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Spalted Wood

spalted silver maple

Wood is such a fascinating medium. Even in the decay process nature brings forth spectacular designs and colors. Spalted wood has been used for many centuries by woodworkers to enhance the visual appeal of objects. The recent publication of a book called Spalted Wood: The History, Science and Art of a Unique Material by Sara C. Robinson et. al. places in one volume all that is currently known about this form of wood. Sara has devoted her academic career to advancing the science of spalting and has collected an enormous amount of information on the subject. It is a very scholarly treatise on the subject and an excellent collection of photographs of spalted wood objects produced over the centuries.

My own interest in the subject has to do with the use of spalted wood in objects turned on the lathe. My first experience with it came from cutting down a tree in my yard in Virginia. It was a maple and I decided the wood was too attractive to burn it. I set it upright on the concrete floor of my garage. Two years later I cut into the log and found it discolored by black lines. My first reaction was that the pretty white wood was spoiled by this fungus attack.Yet as I examined it more closely I found the black lines more interesting as this was a piece of tiger maple and the lines followed the plane of the wood fibers and outlined
the squiggly pattern.

Over the years I have seen lots of spalted wood species. Most of my experience has been with wood with black zone lines. These lines are composed of melanin pigment, the same pigment that makes our skin dark. They mark boundaries to keep other fungal colonies out of that territory which had already been claimed. They are like fences, if you will. Of all the varieties of wood to produce these zone lines I have found silver maple the most dramatic.

spalted ambrosia silver maple

Spalted Ambrosia Silver Maple

This is an example of ambrosia silver maple. The wood is infested with the ambrosia beetle who brings the fungus with him. So around the holes he bores developed the discolored wood, mostly in terms of brown colors.

spalted silver maple

Spalted Siver Maple

This is a more typical spalted silver maple pattern with the dense black zone lines and the white rot contrasting with the darker undigested wood.

Spalted Sugar Maple

Spalted Sugar Maple

This is an example of spalted sugar maple. I my experience the spalting is more diffuse in this species. You can see a few black zone lines but the color changes are more diffuse.

spalted sugar maple

Spalted Sugar Maple

Another example of spalted sugar maple showing the diffuse changes in the wood. Spalting occurs in many other species of wood. Attractive examples are ash, birch, box elder, beech to name a few.

box elder

Box Elder

In her bood Sara Robinson points out that many different colors can arise from spalting wood. The chlorociboria species of fungus produces green colors which were favored by European intarsia artists to portray grass or forests. Other fungi may produce red, orange, purple and blue colors. Extracts of these fungi can even be used for creating dyes. However, she pointed out something that I had already suspected. The red color that comes from box elder is not due to fungal activity but is produced by the tree in response to injury.

The dramatic red color of this box elder piece is not due to fungal activity but is produced by the tree in response to injury. If someone would get around to study it they might find that the pigment has some anti-fungal or anti-bacterial properties or yet some other interesting quality.

spalted Norfolk Island pine

Spalted Norfolk Island Pine

This is a Norfolk Island pine hollow vessel with the characteristic blue diffuse staining of pine by fungal attack. As I had already turned the lower piece of this with the colorful symmetrical knots I almost discarded the remainder but on a whim turned this vessel and found it interesting.

Robinson goes on to tell about how other woodworkers induce spalting. David Ellsworth takes logs and lines them up about an inch apart and then covers them with leaves and leaves them on the ground for a year or so. The practice of coating the wood with chips from spalted wood turnings, coating with beer or other substances Robinson believes is a waste of time. She points out that the fungi eat the easiest food first so these coatings just delay the fungus getting into the sound wood. The fungal spores are everywhere and cut wood comes already inoculated. She does go on to talk about commercial efforts to induce spalting but this goes beyond the turners interest but the information is available in the book.

My own technique for inducing spalting is based on my first experience. Take a log section, set it upright on a concrete slab floor and now I cover it with a plastic bag. You want the wood to stay damp but not soaking wet. Moisture wicks up through the concrete and up the wood fibers at just about the right speed. I leave it there for one to two years and have been rewarded with very attractive spalting.

Turning spalted wood produces some challenges. The wood has been partially digested by the fungal enzymes and it is not as dense. You may have noticed that a spalted piece of wood is light in weight. When sound wood is next to spalted wood it can lead to tear out. Cuts need to be light and sanding may be the only way to get a smooth surface. That surface will be more porous and won’t take as high a shine when finished but the interesting colors in the wood make up for that “defect.”

The easiest way is to let nature do the word for you. Check out wood that has been down for a year or two. Look at dead standing trees. You may find hidden treasures.

spalted hop hornbeam

Spalted Hop Hornbeam

This was a dead hop hornbeam trunk. In Vermont they call it hardak. I just bored down the center of the log to get this vessel with interesting visual appeal. Hornbeam, also called ironwood, is very hard so there was a lot of tear out but the color contrasts between the white rot and the normal wood was so striking that the tear out is not noticed.

So, most spalted wood has already been created for you by nature. You can assist the process if you wish but don’t fail to discover the joys of working with spalted woods.


Making Wooden Bowls from Unwanted Wood

In every community in which I have lived, and there have been quite a few, there always seems to be unwanted wood. This can be a real boon for the wood turner. The wood species may be very plentiful such as cherry in Kentucky. Horse farmers felt that the huge cherry trees in the pastures harbored tent caterpillars which made the colts sick. So they cut down huge cherry trees and left them in the fields. In Albuquerque, which is high desert, wind would take out trees that had been planted and the cut wood was just left at curbside to be hauled to the dump. In Maryland the power company would clear right of ways and just leave all kinds of hard woods for the taking. Storms everywhere take down large trees in city lots and disposing of the wood is a headache for the owner.

Here in Vermont, where I currently reside, the same rule applies. Dutch elm disease was first reported in the US in 1928. It is caused by an invasive beetle that may have started in Asia and spread to Europe from where it made it to the US in infected lumber. Every where I look here in Chittenden County there are dead elm trees. Some are small but others are more than 12 inches in diameter. When they are finally taken down they have been standing dead for several seasons. No one seems to want them. Elm has interlocking grain that makes it hard to split. Early settlers did not like elm because of its peculiar odor. So there the trees stand.

My first experience with elm was in Albuquerque, New Mexico. Siberian (or “Chinese”) elms were widely planted in the city as they grew rapidly and provided shade. Someone gave me some logs. The wood was not very attractive to my eye and it was very hard to split. It did not take a good finish.

So, when my mother-in-law in Shelburne, Vermont asked me to take down some dead elms from her yard, I did not think I wanted any of the wood. When the time came, however, I could not resist salvaging a log or two. It was attractively spalted, was very hard and turned well and accepted a nice finish, much better than the finish I could achieve on Siberian elm.

When I noticed some dead elms across the street from where I live, I asked if I could have some wood when they took it down. I showed them a bowl from the previous elm bowl I had made and they were interested. One Saturday this summer I hear a chain saw and followed the sound. The neighbor was taking down his dead elm. He not only let me have all the wood I wanted but brought it over to my shop. The rest went to the dump.

Below are examples of the finished products.

diffuse gray spalted wooden bowl
I find the color and grain pattern in this bowl to be interesting and attractive. The diffuse gray spalting adds additional interest.

diffuse gray spalted wooden bowl side view
This is a side view of the above bowl.

spalted bowl mother-in-law
Here is the small bowl from my mother-in-law’s tree. The spallting, both linear and diffuse in the upper left side adds visual interest to the piece.

natural edge bowl dead elm
Here is a natural edge bowl from a spalted dead elm from down in the lower end of Addison Counthy. It was just going to sit there until it disintegrated as no one had interest in the wood. The spalting followed the annual rings and gives a visually appealing pattern.

So, if you just want to stick to what the wood merchants sell, you will be missing some very interesting and attractive wood which is free for the asking. Unwanted wood is a headache to the property owner but a boon to the turner. If you give a bowl in return you make a fast friend.


In Praise of the Bandsaw

I would like offer my experience with the most important saw in my shop.
Next to my lathe and bench grinder the band saw is the tool I use the most. My experience is that wood is everywhere for the asking. Neighbors are happy for you to take wood from downed trees off their hands. This can vary from large limbs to major trunks.

With a chain saw, also an important saw, I cut the fresh wood to lengths. Then I use my bandsaw to rip the pieces in half through the center growth ring. With the band saw I can cut a circle which will fit on the bed of my lathe. I find my 14 inch Delta is good for smaller projects but I rely heavily on a 21 inch Grizzly band saw which will cut bowl blanks 14 inches thick. My advice is to get the largest band saw you can afford. With the two saws I find I don’t have to waste so much time changing blades. I use a 1/2 inch blade on the large band saw and a 1/4 inch blade of the smaller saw. The thinner the blade the tighter radius it will cut.

As most experienced turners know, there are many non-commercial wood species which possess beautiful grain patterns and colors. With a band saw you can experiment with these different woods and may find many treasures lurking in wood that has been rejected by commercial loggers. Further, wood with wild grain patterns tend to be rejected by loggers and these may be of the greatest interest to turners. With a band saw you can rip a crotch piece of wood to discover what is inside.

As I don’t limit my woodworking just to bowls, I find the band saw invaluable for ripping out small planks for making spoons and other treen ware. In addition you can rip out turning squares of various dimensions for turning rolling pins, boxes and cups. What may start out as a candidate for a bowl blank could have a defect
but the same piece may be suitable for the non-defective part to be ripped into planks and turning squares.

Just a word of caution. The band saw may make re-sawing so easy that you cut more wood than you have room to store and dry that which is not turned green. Treen ware is not critical due to the small size of the spoon or spatula and it tends to dry without difficulty though I prefer to shape it when dry. However, when you turn lidded boxes out of wood it must be absolutely dry. If not, you may find that a perfect fitting lid just off the lathe will not fit after the parts dry and warp. So if you rip the turning squares you need to have a place for them to dry for a year or two depending on the thickness of the square.

So, get a band saw. If you cannot afford one make friends with someone who does. It is certainly a saw that can be shared. It used to be that lumber yards had a bandsaw where you could get wood re-sawn. I was visiting my son in Ojai, California this February and the local lumber yard did not even own one. I finally was able to track down a local contractor and he was happy to let me re-saw some olive wood for the price of a new bandsaw blade.

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Invasive and Unwanted Wood Species

I was doing a show in Maryland and a woman looked at a bowl and exclaimed:  “That’s Norway maple isn’t it?  Well at least it is a dead one!”

She worked for the government in an agency that combatted invasive species.  In spite of all the hype I have never known an invasive species that took over the whole world, except for mankind, I guess.

My own feeling is to make the problem the solution.  If you can make something beautiful or at least useful from an invasive or unwanted species then then next thing you know it will make it to the endangered species list and another government agency will be getting involved.

A few months ago a woman brought me the biggest buckthorn log I have ever seen.  Buckthorn is an invasive species here in Vermont and elsewhere.  It is a low scrubby bush with bad thorns and it spreads easily.  You will find it in overgrown meadows.  It is not a climax tree and gets shaded out by the taller climax growth hardwood trees.  The wood is very hard and tends to have twisted grain which checks easily.  However, like any dense wood it turns well. Here are some of the items I made this woman from the chunk of buckthorn she brought me.

buckthorn wooden bowls

buckthorn wooden spoons

To my eye the wood has a lovely orangish tan color.  I was trying to tell my son who had never seen it what it was like. I told him that it looked exactly like buckthorn.  Don’t know any other wood that looks like it.

buckthorn wooden spoons close up

A close up reveals the interesting color variations of the grain.  You can make out a little curly pattern on the spoons. Who would have guessed you could make anything useful out of buckthorn?  I once heard a definition of a weed being a beneficial plant the use for which has yet to be discovered.

This same woman, who had been doing some land clearing, also brought me what I would describe as a cedar fence post. Where I come from in Virginia we call it common red cedar.  Actually, it is Juniper virginianis, a juniper and not a true cedar like we have here in New England.  It was about five feet long and no more than six inches in diameter.  It surface was deeply corrugated.  She wanted something made out of that!  Here is what came out:

red cedar wooden cups

Frankly, I was surprised at the interesting patterns which appeared with spindle turning this aromatic wood.  A man from New Zealand spent a day in my shop recently and I let him turn a piece of this wood.  He was delighted as no wood of that color grows in New Zealand.

Going back to that invasive Norway maple here are some things that came from that “dangerous” species.  These were ornamental trees planted in people’s yards that died or had to be cut down for some reason.

Norway maple hollow form

spalted norway maple hollow form

norway maple bowl

norway maple bowl

norway maple bowl

So, for my money, everything has a use.  Don’t overlook the unwanted and invasive species.  I’ll take all the Norway maple and large buckthorn I can get.

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What Can I Do With That Wood? Part 2

Developing skill with a chain saw and having a large bandsaw at my disposal has allowed me to make use of a wide variety of woods. Commercial lumbering favors wood that can be sawn into boards and that has qualities favored by carpenters and cabinet makers for construction. For this reason there are many non-commercial species in the US which are overlooked by the commercial interests. Many, I think, are just as spectacular or quietly beautiful as any imported exotic wood species.

In a sense I am a wood recycler. Trees are always falling in storms, dying of old age, or having to be removed because of proximity to a house, pool, etc. The wood then becomes a liability to the home or farm owner (unless they have a hobby like mine).

One of the most unwanted tree here in Vermont where I am living is the box elder. It is a poor cousin to the sugar maple. Yet unlike its cousin its wood is not hard, does not make good fire wood and it grows like a weed, especially in wet areas. In short it is considered a trash tree.

Yet it take a good finish and it has one interesting feature. When injured the wood produces a pink or red color which contrasts sharply with the creamy white wood of the rest of the tree. My research suggest that this pigment is a non-specific reaction to injury. You see it where a branch has broken off or where there was disease in the center of the trunk.

The color varies from light pink to scarlet red. Unfortunately the color is not fast and fades into a light brown over time. No one knows how to prevent this color fading. Yet while it lasts, it can be very attractive. It is the nature of all wood to fade or darken with the passage of time. You may have noticed that furniture under a sunny window changes color.

If you have ever seen a 17th century antique you will note that it is black. Wood as it deteriorates reverts to elemental carbon which is black. You may have noticed that you have faded a bit with advancing years yourself. So don’t be too hard on the box elder because the color is not permanent. If the design of the object made from it is good then it will be enjoyable in spite of the changes just as you consider yourself to still have value in spite of the changes in your physiology induced by aging.

red box elder hollow form

This is a box elder that is about as red as I have ever seen. It almost shouts at you. It was from a tree that fell over in a storm in the town of Williston, Vermont where I live. It was kindly given to me by the owner who was happy for me to remove some of the wood on his lawn. I, in turn, was very happy to get this unique log and was happy to share a hollow turning from this log to the donor of the wood.

box elder wooden hollow form

This is a hollow vessel from the same log. You can see that some of the color has changed into a lovely light brown with differing intensities. So I feel that Nature has hidden some great beauty in a lowly short lived brittle tree of relatively soft wood which grows like a weed.

Butternut is another of my favorite woods to turn. It takes patience as the wood is softer than its cousin black walnut and tends to leave a fuzzy surface. It takes extra sanding to produce a good surface but the extra work may be well worth it.

butternut hollow form

Notice how the soft curves of the grain are reflected in the soft contours of the bowl. Notice how the soft shades of brown of the heart wood blend into each other. This is the subtle beauty of Nature at its finest, in my opinion.

butternut hollow form

Yet we are losing our butternut stands to a fungal disease known as butternut canker. This hollow vessel shows two black streaks where the fungus has invaded the tree. In time it will kill the entire tree. This tree had died and was given to me by the homeowner.

Even in disease we can see beauty in Nature. Those black defects can be considered artistic accents to an otherwise plain design.

Butternut Vase

Here is another example of the softness of colors in the butternut. The creamy sapwood blends gradually into the soft warm browns and tans of the heartwood. The simplicity of the design does not detract from the subtle color variations created by Nature. In my opinion, Nature is the real artist and my job is to show the beauty nature has already created.


Shop Safety Tips For Woodturners

Over the years you come on tidbits of information that become a part of your routine. Woodturning is a hazardous hobby or profession. When I attend my woodturning club meetings I am constantly seeing members who have managed to injure themselves. If you have tried to get insurance to cover your woodturning activities you know that the insurers realize that injury is common and they may be severe and the insurance premiums reflect that. So here are some pointers to file away in your mind.

Most would agree that it is not good to be between a rock and a hard place. A tool rest does not have much give to it. When a finger is caught between a spinning block of wood or a four jawed chuck and the tool rest it is a formula for pain at the least and a disaster at worst. So learn to rotate your work piece by hand before you turn the power on and keep fingers clear of the gap between the tool rest and the spinning wood.

One of the conditions which can encourage such a mishap is an ornery banjo. The banjo slides on steel ways. Into it is fitted the tool rest post. There is little tolerance between the banjo and the lathe bed (or ways) when the lock released. So just a small amount of dust or wood chips can cause it to seize as you try to slide it up or back. So you wiggle on the lock down handle and push with the other hand. Often it will stick and then when heft is applied it suddenly gives way and slides into the moving work with unpleasant repercussions.

We all know that we are supposed to turn the lathe off when we adjust the banjo holding the tool rest. Yet I doubt there are one in a hundred turners who regularly do this. The reason is that time is money. It takes extra time to do this step.

What may help is to make sure that the banjo slides easily on the ways of the lathe. It is steel on steel and friction is a problem, especially when dust or chips are on the ways to reduce the clearance. It is not original with me but I read somewhere that if you take an ordinary piece of wax paper and rub the ways frequently, it makes the banjo slide easily.

The first time I tried it I was surprised at how well it worked. The wax leaves no sticky residue. It just reduces friction by transferring a minute amount of wax to the steel surface of the ways. Now I keep all my used wax paper sandwich wrappers just for this purpose. I had tried grease but that just attracts dust and chips. Spray on silicone did not seem to last very long. The wax paper was just the ticket for me.

Just bear in mind that the banjo may slide so easily that it flies further than you intended and can run into the spinning headstock if you are one of those who refuses to turn the lathe off when adjusting the banjo. Whatever, wax paper really makes the banjo slide on the ways. It has to be repeated frequently but will reduce the cussing you do when it sticks and it saves time and is much safer.

Another point I want to make is that a sharp piece of spinning wood will cut you just like a scalpel. Someone in our club recently cut a tendon on a finger. This is no trivial injury. So I make it an absolute rule to sand off any sharp spinning edge of wood that I have created, with my gouge preferably before I cut myself. When I ignore this rule I get blood on my lathe and tools. So, really, sand that sharp edge down as soon as you create it.

As a physician who has taken care of patients with chronic lung disease I know the dangers of breathing particulates. Thus I have made it my rule to don a dust mask as soon as I enter my shop and don’t remove it until I leave. It makes conversation difficult but I don’t do a lot of talking in my shop for that reason. Enough dust will make anyone wheeze. It is a signal from nature that something is wrong that you need to correct. I want to be turning for a long time and breathing easily for a long time as well. Prevention is better than cure.

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Scraping and Simplicity

Sometimes solutions are so simple you wonder how you ever overlooked them. I make a lot of bowls. My gouge technique is not so perfect as to leave an interior free from ridges so I frequently use a scraper. Both the interior and exterior of bowls have given me a problem with end grain tear out. The gouge or the scraper just makes ragged tears in the end grain and the more I scraped the worse they would become.

I had read of some solutions. One was to put oil on the problem area and then scrape. Some say that water will also work. This softens the fibers and make them easier to finish cut. I have tried these with modest success but in reality they are very messy.

Another suggestion was to make feather light cuts. That is easy to do when cutting with the grain but when you get to the end grain the gouge or scraper just seems to want to dig in and make the problem worse.

To sand out these areas of end grain tear out is laborious and time consuming. The dust it generates is just no fun. After years of turning bowls I seemed to be no further along.

I belong to a local woodturning club here in Vermont. It is the Woodchuck Turners of Northern Vermont. One of the functions of a woodturning club is to bring in demonstrators who have gained proficiency in some area of the craft. Our most recent meeting was host to Rich Detrano (www.richdetranowoodturner.com, e-mail: richdetranowoodturner@live.com) Rich does lovely hollow turned pieces.

Rich was demonstrating how he does hollow turning for people in the club who wanted to learn the skill. What I learned from Rich was so simple but it hit me like a ton of bricks. He said the solution to most problems on the lathe can be solved by slowing or raising the speed of the lathe or by raising or lowering the tool rest or by moving the tool rest closer to the work or further away from the work.

Now that is pretty simple and straightforward. I had learned that to scrape properly, your tool cuts better when it is presented to the wood somewhat above the center of the axis of rotation. If it is below the center it will just rub and not cut at all.

I had also learned that if your tool was too far over the tool rest it tended to be hard to control and took a lot more work. So I had learned to move the rest closer to my work and enjoyed the results of this simple adjustment.

When turning I generally wanted to cut as quickly as possible. So I would push up the speed as much as I dared. Never, in my wildest dreams did it occur to me to slow the lathe when I scraped. When I did, scraping became a joy. Instead of vibrating over the end grain tear out it tended to cut right through the irregularities. The shaving were very fine and with repeated passes I found that I could eliminate the tear out better than I ever had before.

When you think about it, it makes perfect sense. The faster you drive your car over a depression, the higher it bounces. When it comes down, it comes down harder and tends to dig the next rut. This is how you end up with a “washboard road,” the kind of dirt roads I learned to drive on as a kid. Just like that when the scraper or gouge hits a rough spot of tear out at high speed it tends to bounce off the rest and then it comes down hard to dig into the next area of end grain. Thus the end grain tear out gets perpetuated and even made worse.

By slowing the lathe speed, and you can adjust what speed works best for you, the tool cuts evenly and does not vibrate and you have greater control.

How I could have overlooked something so simple all these years is beyond me. I don’t ever remember reading about this point although I may have and it didn’t register. So I am very grateful for Rich Detrano making this point so clearly and succinctly. To solve problems, slow the speed, raise the speed, lower the rest, raise the rest, move the rest closer or further away.


Center Finding Device for Jam Chucking

As an avid turner I may turn a hundred bowls a year. Turning the bowl, either wet or dry is pretty straightforward. However, when you remove the finished bowl from the face plate or the four jawed chuck, remounting it to turn the foot is another matter.

The key thing here is to get the tail stock in the exact center of rotation when the bowl was reversed and you finished the outside and inside of it. Now you have removed the bowl from what was holding it and need to get it to spin on the exact same axis of rotation but with the bowl reversed so you can finish the base of the bowl and the foot, if any.

If you are not successful in this, when you try to blend the foot with the body of the bowl, there will be unevenness where the curve of the bowl meets the new curve of the foot or base. One side will be high and one side will be low. It won’t sand out easily either. So I would like to take you step by step through the method I have found works best for me.

First of all, I use jam chucks. I know about vacuum chucking but at this point in my career I just don’t want another piece of apparatus with a long learning curve attached. Jam chucks are so simple, easy to use and durable. Nothing to break or get out of adjustment.

Here is a selection of jam chucks I use. First I purchase inexpensive aluminum three inch face plates. To these I screw a piece of 3/4 inch plywood cut in a rough circle. I put this on the lathe and true up the circle with a gouge and then turn a curved bevel on the edge which will fit into the inner curvature of a bowl. I have several sizes to suit the size of the bowl being finished.

jam chucks

Here is the back side of the jam chuck showing the aluminum face plate which has been screwed to the plywood. These are much less expensive that the Oneway steel face plates I use for mounting bowl blanks to the lathe for initial turning. Since there is no great strain on the jam chuck it does not need to be so sturdy.

jam chuck back

This is how the jam chuck will fit into the inside of a bowl Ordinarily the inside and exterior of the bowl would be finished but I didn’t have one handy when I took these shots. So this bowl has yet to be finished but the principle is the same.

how jam chuck fits into bowl

Now we see the jam chuck mounted to the lathe and the bowl to have the foot finished being shoved by the tailstock against the jam chuck with a pieced of foam between to prevent marring of the a finished surface and to prevent slipping and heat scoring of the bowl interior.

So this is how a jam chuck works. You use the tail stock to press the outside of the bowl against the jam chuck which fits inot the interior of the bowl or object. It could be a box or a hollow turning just as easily. You turn off the excess wood of the tenon and then remove the last little plug with a saw or chisel and sand flush. If it is a dovetail base then you turn off the dovetail and blend the curve with the base of the bowl. In this case you may be left with a hole made by the tail stock center.
That, too, can be sanded off if you left enough wood in the center.

The important point is to get the center of the tail stock center into a spot which is the exact center of the axis of rotation of the bowl which was established when the bowl was turning the opposite way before it was removed from the face plate or four jawed chuck and reversed. I f you don’t find the exact center then the bowl will wobble and the gouge cuts on the foot will not blend with the curve on the upper part of the base.

dovetailed recess

Here we have a walnut bowl. Instead of having a tenon on the base which would be held in the chuck, it had a recess turned in the base. The chuck jaws have been lowered in the recess and then the jaws expanded into the dovetail recess cut in the base. Whether the bowl was held by a tenon or by a dovetailed recess the tenon has to be removed or the recess has to be blended into the base of the bowl to create a nice finish on the bottom of the bowl.

bottom of the bowl

Here is the base of the bowl and you can see the dovetail recess.

dovetailed recess

With more magnification you can see that the exact center of the recess is not apparent. To pick a spot would be just to guess. and with the slightest error you would get a wobble. I have seen very experienced woodturners use trial and error methods over and over and even resort to pounding on a vessel to try to get the tail stock center to get in the right spot. You do this enough times and you scar the area around the center and it becomes harder and harder to find the exact center.


Here is a device that is simplicity itself. It makes quick and easy work of finding the exact center of rotation of the vessel in one step. It consists of a turned steel cylinder with a wide flange on top. This has been machined to fit exactly into the same hole in the four jaw chuck as the threads on the drive center of the lathe. I use Vicmark chucks and the fit is perfect. I also use a Nova chuck and the fit is a bit loose on that one. So to get around this I put a couple of turns of painters tape around the cylinder until it fits into the hole in the chuck snugly.

small steel round with point

The smaller black steel round is made to fit exactly into a hole milled into the larger steel cylinder. You can see from the picture above that this has a small point on the end.

inserting the cylinder into the chuck

Here the cylinder is about to be inserted in the base of the chuck.

cylinder is seated

Here it is fully seated with the inner rod with the point inserted in it. Since this bowl did not have a plug tenon turned on the base but rather a dovetail recess the pin drops below the level of the insert. No matter. If the pin is above the surface of the insert I just give it a knock with a wooden mallet. I use wood to keep the head of the pin from spreading which would happen if I repeatedly hit it with a steel hammer. You can see that if the head was spread then it would not seat properly when the striking surface was low as in this example.

using a drift pin to strike

Here I am using a drift pin to strike the pin which will leave the center mark on the bowl. This allows me to strike a blow even thought the pin is below the surface of the insert.

the wood is marked

Now the jaws of the chuck have been removed from the bowl bottom and you can see the dark shadow cast by the dimple made by striking the pin in the previous step above. Note that the exact center is not where you think it should have been using visual clues from the base of the bowl.

the wood is marked

In this picture I have mounted the bowl against the face plate which is attached to the drive center of the lathe headstock. I have deliberately pushed the tailstock against the bowl base to hold it for the picture but have not centered the point on the tail stock in the hole punched by the center finding apparatus. I wanted to show how clear the marking is for the center point. From this angle we get more shadow and contrast than with the picture where we were looking face down into the hole which was shown previously.

mounting tail stock

Here the tail stock has been firmly mounted into the exact center of the bowl.

jam chuck mounting

Once again here is the jam chuck with the bowl centered exactly on its axis of rotation. The foam insert between the jam chuck and the bowl makes the fit better and prevents friction marks and scarring by the face plate twisting against the bowl inner surface.

I turned on the lathe and the bowl turned perfectly on its original axis and there was not the least wobble. With this the foot can be finished and blended in with the base of the bowl without a trace of where the two curves met.

I purchased my center marker from Craft Supplies several years ago and have used with pleasure ever since. (www.woodturnerscatalogue.com)

I have learned over the years that if there is a tool you like it is best to purchase it now rather than wait. When you are ready the tool may no longer be available. This has happened to me enough times to make me sensitive to this point. When everyone has the tool, the sales collapse and the manufacturer turns his attention to something new. After all, this tool will last a lifetime.

Some of the very best tools are simple, easy to use and save you huge amounts of time and save you from frustration over the years. This, in my opinion, is one such tool.


What Can I Do with That Wood?

Since the industrial revolution people have become removed from nature.  Things that were taken for granted in past centuries are not obvious to modern city dwellers.  The novice woodworker usually purchases dimensional lumber and turning blanks from commercial houses.  Often the species are limited to oak, maple, walnut, cherry and a few other species.

Being frugal by nature I have always gotten my wood in the rough.  Neighbors give me trees or logs or I find them left by the side of the road by utility companies.  Much of the wood I find comes from inside city limits where the wood is a liability for the home or business owner.

There are many non commercial species that one runs across.  Timber men want tall straight trees with no defects, crotches or knots. Many trees do not have such a growth pattern and don’t find their way into their inventories.  However, many are very beautiful or have unique characteristics.

I want to share my perspective as a turner and treen ware maker about some of the woods I have encountered.  This is not meant to be an exhaustive list but just my own personal experience.  I will start with the more common trees one encounters.

Oak is probably a very underrated species for wood turners.  I had a real bias against oak as rough turned bowls always seemed to check on me.  I would take large blanks out of the paper bags in which they had aged only to find to my dismay large ugly checks going all the way through the bowl making it useless.

A few years a large red oak had died across the street and when it was taken down by the professionals my neighbors said I ought to get some of it.  I told them I was not very interested as it always seemed to check on me.  Curiosity prompted me to walk across the street and actually examine the tree.  Lying on its side it was about five feet high.  It had lived 150 years by ring count.  The trunk had been sectioned into boles about 16 inches in length.

After inspecting one of these massive boles I determined that I could get some quarter sawn two inch thick pieces to make large platters with.  So, with permission, I ended cutting out a platter blank from the heart out to the top, bottom and each side of the bole.  However, it was so large that I was able to get four more from the remaining quarters.  Looking at the pieces that remained I could not make myself leave that beautiful wood in the snow.  Even though they represented eight sections of the bole they were still very heavy to lift into my van.

I had just learned to make natural edge bowls and decided to try that technique on these blanks.  You had the black bark, a layer of spalted sap wood and the red heart wood for nice contrast.  Now the technique for turning a natural edge bowl is to turn it to finished dimensions on the lathe.  I leave it attached to the face plate for a few days and then can begin sanding before I reverse chuck it to finish the foot.

The secret is to turn the bowl thin and make sure the bottom is s trifle thinner than the rim.  I partially make a parting cut to isolate as much of the wood  screwed on the face plate from the foot of the bowl to make sure that it allows the base and foot to dry along with the rim at the same speed.  This was a trick I learned from Fred Williamson, a fine bowl turner in the Crozet, Virginia area.

To my amazement six of the seven bowls I turned had absolutely no checking.  Now I was hooked on oak.  Here are some examples of the 150 year old red oak.

150 year old red oak bowl

red oak bowl

On another occasion I was offered some 350 year old white oak.  It was part of a stand of virgin timber in a park in Baltimore, Maryland.  This tree was just outside the park but part of the stand of virgin timber.  Most of the trunk had already been cut up for firewood .  I took three pieces from very large limbs.  I remember not being very impressed at the time.  I split each piece and got six blanks to work with.  As soon as I put my gouge to the wood I realized I had something special.  The wood worked with unusual ease for oak and it completely drew me in.    I guess anything that can live for 350 years has something special going for it.  None of the six bowls checked and the woman who gave me the wood bought all five that I had completed.  I have one more that was not finished at the time and every time I look at it I wish I had gotten more.  The point of this is that oak is a lovely wood and when handled correctly gives wonderful results.  The big plus is that oak is everywhere. Here is a picture of the white oak bowl.  The light areas are due to spalting of the sap wood.

350 year old oak wood bowl

Cherry has to be one of my all time favorite woods for turning, treen ware and furniture. It is hard and does not carve easily like mahogany but in every other respect it is without a peer. It is tight grained, machines easily, takes a beautiful finish and is very durable. All woods tend to darken with age. Wood is carbon and if you have ever seen any 17th century antiques they are black. All wood reverts back to this color. Cherry wood has a dye in it which turns a beautiful deep red with continued exposure to light. Bowls that have been to many outdoor shows with me over the years are ever so much more pleasing to my eye because of that deep cherry red they have assumed and look quite different from their pale peers which have been newly turned. So, you don’t have to keep your cherry bowls out of the sunlight, it just makes them prettier. Other woods such as walnut tend to bleach in the sun but not cherry.

The reason I know about the dye in the cherry wood is that it stains my clothes like no other wood I work. My wife is constantly complaining about the stains it leaves on the towels. So you woodworker be careful what you do with your cherry dust.

cherry wood bowl

This is a cherry bvwl which has begun to take on that deep red color.

new wood cherry wood bowl

This is a more newly turned bowl. In time it will get as dark or darker than the cherry bowl above.

The crotch of a cherry tree is something in which timber men and fire place log splitters have no interest. Yet within these pieces are designs of spectacular beauty. Nature sews a crotch together with wood cells growing in all directions. Cells growing in one direction diffract the light differently than those growing in another direction. The result is light and dark ares which some have likened to a flame hence the name flame grained cherry. Below is a platter showing this feature. I have learned to cherish irregular grain. Flame grain is also spectacular in other woods such as walnut, mahogany, etc.

crotch wood cherry platter

Don’t overlook ornamental cherry trees. I was asked to make some things from a flowering cherry whose roots were growing into a swimming pool. It was not particularly large but I took some of the best pieces to the shop. Below is what came out of one. This wood took a beautiful finish and the yellow sap wood was most attractive to my eye.

flowering ornamental cherry wood bowls

flowering ornamental cherry wood bowls

Maple is another wonderful wood. For those not familiar with the commercial timber nomenclature they use two terms. The first is rock maple. This generally means sugar maple and sometimes includes red maple. The second is swamp maple. By this they mean all other maples. The maple family is large. There is little question but what sugar or rock maple is a marvelous wood to work. It, too, is tight grained, but has a light color and machines well. It takes a lovely finish. Over time the maple turns a lovely yellowish gold color. My experience is that it takes about 20-30 years for this color to become fully apparent but it is very warm and pleasing to the eye. Stains cannot really do it justice. I prefer an oil stain without pigment and just allow the wood to age.

The maple is subject to genetic variation in how the wood cells grow. A wavy growth pattern can give us curly maple, tiger maple, fiddle back maple and birds eye maple. Norway maple, not native to America but imported as an ornamental tree, has some spectacular grain patterns as evidenced below. I have heard that the Stradivarius violins and cellos may have been made of Norway maple. If someone offers you Norway maple, it would be prudent to take them up on the offer.

Norway maple wood bowl


Turning a Natural Edge Bowl-A Step by Step Guide

Some people learn by reading but others do not.  So I include lot of pictures with the text to help those others.

In the previous blog post I showed how to use a chain saw to prepare bowl blanks for mounting on the lathe.  In this post I show the steps for mounting the blank on the lathe and turning a bowl.  Specifically I am going to show how to make a natural edge bowl.  In natural edge bowls the outside or bark side of the blank will become the rim and the inner side ( heart wood) will become the base.

Natural rim bowls have visual appeal and certain advantages.  Since the outside of the log is curved the natural rim bowl will have an undulating edge going from high to low and back again.  It also will have bark on the outer part of the rim, provided it stays on, and a ring of lighter sap wood with darker heart wood in the center of the bowl.  This gives strong visual contrasts which many feel are attractive. Since the rim is already curving, any warping of the bowl rim as it dries will be undetectable.  Finally, the bowl can be turned and dried in a couple of days while a cut rim bowl may take months to dry and then has to be remounted to the lathe and turned again to hide the warping that inevitably occurs and achieve the final wall thickness.

For some, having the two higher sides of the rim in the same plane and the two lower sides of the rim also in the same plane are desirable.  It gives a feel of balance.  So I am going to assume this is the desire in this piece and will show how to mount this blank of cherry wood to achieve that end.


mounting blank to the lathe

Here I have brought the blank to the bed of the lathe.  My first job will be to determine the plane of the axis of rotation to give the effect mentioned above.  If I just mounted a faceplate to the flat side in this picture the high sides of the rim would not be in the same plane.  That also goes for the low sides of the rim.  Note that I have not added the faceplate yet but am going to turn this blank between centers.  To do this you need a large spur drive center in the head stock and you need to cut away the bark in the center so that the spur drive center can grip into the wood and not spin in the loose bark.  First I fit the drive center into the hole in the bark on the outside of the blank and then draw the tail center up to the other side to pin it securely.


pinning the blank between centers

Here I am pinning the tail stock into the heart wood side of the blank.  This is just a temporary fix and much adjusting will be needed.

It is not just a matter of putting the tail stock into the center of the circle that is the base of the blank.  In this job it would be nice to have four arms but I have learned to make do with two. The blanks may be heavy and awkward.


Now I have the tail center in the approximate location and am ready to clamp the tail stock to the lathe bed.


Here I have clamped the tail stock to the late bed and am ramming the tail stock into the blank to hold it securely.


Now I am ready to turn the blank by hand to make the final adjustments.


From visual inspection I have determined that the flat plane of the heart side of the blank made with the chain saw is not the plane I want.  Here you see that I have changed the angle quite a bit by lowering or raising the position of the tail stock.


Using my finger as a fixed reference point I slowly turn the blank between centers and see if I can  get the higher edges of the rim to lie in the same plane.  I make adjustments by either raising or lowering the position of the tail stock center on the blank at the heart wood side of the blank.  It is a trial and error exercise and it may take several adjustments to make the satisfactory change.  Here is where an extra set of hand would come in handy.

Once you are satisfied you have the high sides of the rim adjusted properly then you need to do the same process for the lower sides of the rim.  Once that is done you need to go back and check and make sure that both high and low sides are properly adjusted and make any slight changes that are needed.  Now you are ready to prepare the foot so that it is completely flat and in the plane that is perpendicular to the bed of the lathe.


As you can see from this photo and the one below that significant amounts of wood needed to be removed to true up the base allow the face plate to sit flat on it.


Here the truing up process is just about complete and the blank is ready for removing from between centers  for faceplate attachment.


Here I am using a wood carving gouge to remove the button of wood so that the face plate will sit flat on the base.


I like using a wooden mallet on the wood handled gouge.  This is one that I made which has a head made of dogwood.  It is a very hard wood but does not damage the wood handle of the gouge.


Now I am using a power drill to mount a six inch face plate to the heart side of the blank.  I really like the Souix angled drill shown here.  I find it more ergonomic for this use as well as for bowl sanding.  Everyone has their own preference for fasteners.  Frankly,  I just use sheet rock screws as they are cheap and quick.  I have tried thicker screws, stainless steel screws and just keep coming back to the sheetrock screws.  To compensate for the reduced holding power of these screws I just use more of them.  I prefer the square drive screws.  It is a good idea to measure the amount of the screw that will protrude from the faceplate.  This will tell you how much wood must remain waste wood on the bottom side of the bowl.  There are other ways of getting around this problem such as having the base go inside the circle of screw holes but for now we won’t go into that.


Here I am sharpening my 5/8 inch gouge with an Ellsworth jig.  I find the Ellsworth grind the most satisfactory one I have used.  You will find a description of David Ellsworth’s book in other blog issues I have written on this site.


Now the outside of the bowl has been finished.


Here I have started to turn out the inside of the blank.  When using a large blank, the banjo of the tool rest will not slide under the blank.  That means that you have to think ahead.  When doing the outside you need to slide the banjo all the way down to the head stock before screwing the face plate and bowl blank to the lathe.  When you want to do the inside of the bowl you need to remove the faceplate and bowl blank from the head stock and slide the banjo towards the tail stock and then reattach the face plate to the head stock.


Here I am sitting on the lathe bed as I hollow the inside.


Here is more of the same with the chips flying.  Turning wood which is wet allows for more aggressive cuts as the wood is softer (by 40%) when wet.


As I go deeper into the bowl I switch from the straight tool rest to a curved one so my  gouge is supported closer to the cut I am making.  It is safer and easier on the turner as you have greater mechanical advantage from a longer lever arm.  The tool rest is the fulcrum and the closer the fulcrum is to the cutting end of the gouge the greater the mechanical advantage.



Here I am measuring the depth by placing a straight rod, in this case my gouge, to the center bottom of the inside of the bowl.  It is good to sight down from one high rim to the other so that you get a true reading of the depth.


I place my thumb on the exact point of maximum depth and then take the gouge out of thebowl and using my thumb mark transfer the depth mark to the outside of the bowl.  Then I make a mark on the outside of the bowl to indicate how deep the bowl is on the inside.  As I  cut the bowl from the face plate this will keep me from making the parting cut too shallow or too deep.


Here I am making a cut to the final uniform thickness of the bowl wall from the inside.  The outside was already set before we began to turn the inside.  It is very important to have the bowl wall thickness uniform  in order to avoid checking of the wood when it dries.  Some will check no matter what you do but if the bowl wall is thin and uniform, very few will check has been my experience.


Every time I am too lazy to use the calipers, I regret it.  Here the calipers are set at a known width and slid down the bowl wall, with the lathe off.  When it begins to hang you know that more wood needs to be removed at that area.  Trimming cuts like this need to be done gently.  You cannot replace wood you have turned away.


Measuring of the bowl wall thickness is now complete.  Notice that in some areas of the rim the bark has come off.  When this happens I remove all the bark.  If it all stays on I leave it on.  Some people love the bark left on for the added contrast.  Others feel it is too impractical to use around food.  The bark edge is somewhat delicate and can chip off.  However, it is not too delicate or it would not have survived being cut to a narrow width with a gouge while spinning at 500 rpm.


In this picture I am removing some waste wood about the base and getting ready to use a parting tool.


Here I am using a thin parting tool to remove the bowl from some of the waste wood into which the face plate screws are lodged.


This is a trick I learned from a master bowl turner named Fred Williamson.  See the article on Fred williamson’s bowls elsewhere on the blog.    I will not complete this cut for several days.  However, I cut in deeply enough to leave only 1 to 2 inches of wood of the base of the bowl still connected with the waste wood with the screws attached.  How deep the cut depends on the size  of the bowl and the size of the faceplate being used.


What this step accomplishes is to separate the bowl base from most of the still wet wood in the waste attached to the faceplate.  I will leave the bowl just as you see it now.  In one to two days it is dry enough on the surface to begin sanding.  I use my Souix drill with sanding pads to do the rough sanding.  If you have ever tried to hold a large curved bowl in your lap to try to do this sanding you appreciate how nice it is to have the bowl still rigidly attached to the lathe so both hands can be used on the sander.  Working near the base, the lathe can even be spinning slowly to speed up the sanding process.  So the one or two inch plug at the bottom is enough to hold the bowl on the lathe but still most of the wet waste wood has been separated from the bowl so that the bowl base can dry evenly.

I am very grateful to Fred for sharing this technique with me.  If you have several faceplates then you can have multiple bowls drying for several days while you continue to turn more bowls from wet wood.

When you have completed the sanding of the bowl on the lathe then just cut through the plug that holds the base to the faceplate with a hand saw.  This is safer for me than parting off a large bowl with the lathe spinning.  If you use a saw, be careful how you angle the cut so that the saw teeth do not cut into the base of your bowl.  Sanding will finish the base so that it looks professionally done.


Here is the finished bowl.  All the bark has been removed and the rim has been trimmed with a pattern maker’s spokeshave and sanded smooth.

To finish my bowls I sand through grits 80, 120, 180 and 220.  Then I spray with dewaxed shellac  (I use Bullseye brand in an aerosol can available from Klingspor) to seal the grain.  Since the shellac has been dewaxed it is compatible with any other kind of finish including oil finishes. Sealing with shellac keeps the oil stain from soaking in the end grain and oozing out later to spoil the surface.  I sand all the shellac off starting with 220 grit and then progress with 320, 400 and 600 grit.  At this point I apply tung oil.  I get a food-safe grade and dilute it with mineral spirits so it will penetrate.  I use anywhere from one to four coats of tung oil waiting 24 hours between coats.  More coats give a deeper looking finish.  Then I like the bowl to dry for a month or more and then use the Beale buffing system I have described in earlier blog posts.  This starts with a coarse abrasive and ends with carnauba wax all applied with a buffing wheel.  This is a real labor saver and results in a low gloss sheen.  I am not in favor of shiny plastic appearing finishes.

Everything is easy when you know how.  With the ability to show text and graphics, it puts the skill of wooden bowl making within the reach of anyone who has the proper equipment.  Woodworkers have been generous to share their skills with me and I am pleased to be able to pass them on to you.