Wall Sculptures

April 4th, 2007

At the April MWA club meeting Duane Gemelke showed us how he makes his unique wall sculptures. The process is deceptively simple: Turn a sort of platter with bead and cove pattern, cut it into strips (straight or wedge shaped), and glue the strips back together at an offset.

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Wood selection

The wood used should have these properties:

Duane started out with Butternut. While easy to sand, it does like to tear out while cutting. Next he tried soft Maple. The problem here was excessive movement due to the moisture introduced while gluing. Currently Duane works with Beech, which provides a reasonable compromise. Other possible alternatives to try might be Hickory or some (though expensive) exotic woods.

Wood preparation

Duane starts out with a board 3/4” thick. The size is limited by the swing of the lathe, so around 10” to 12” for smaller lathes, or 16” for larger lathes. For those larger sizes to boards can be edge-glued together. If the wood does have some figure, a thicker board can be re-sawn to get a book-matched appearance. Later the first cut can be made along the glue line so it will not show.

A small hole is drilled into the center, this will make it easier later to center the board on the lathe. Now a disk of the desired diameter is cut out of the board. Next one side of the disk needs to be flattened perfectly. Start out with a disk of scrap wood attached to a face plate. Flatten the scrap using a light sheer cut and frequently check flatness with a steel ruler. Now our work disk can be mounted on the lathe using the tail stock registered on the center hole to press the disk against the scrap disk. Flatten the work piece using the same technique used to flatten the scrap on the face plate. Light cuts are paramount as the disk is not secure. The remaining bump obscured by the tail stock is then sanded away by hand.

The flattened side of our disk is now glued to the flattened scrap on the face plate. The most secure way is a paper glue joint: Using wood glue glue the flattened sides of the disk and the scrap together sandwiching some craft paper or paper cut from a brown paper shopping bag. Doing it on the lathe, with the tail stock registered to the hole in the disk will make it easy to align it to the scrap on the faceplate. Add clamps and let dry. This will result in a secure bond, but the paper will allow it to be separated once the turning is done.

A less secure method (and hence not recommended) is to use double faced tape to glue the disks together. Duane prefers Heavy Duty Carpet Tape, which contains a thin layer of fabric (available ate Menards and other home improvement or hardware stores). Clamping pressure for about 15 minutes will make the bond more secure.

Turning

Next a pattern is laid out on the wood. Duane uses 3/8” beads and 3/8” coves, separated by 1/8” steps. Mark your layout with small marks, mount the disk on the lathe, and transfer the marks in the round by rotating the disk.

Cutting the beads and coves onto the flat face is a lot different than with spindle work. Gouges are not well suited due to the extreme tool angle required. On larger lathes a short gouge with a short handle could be used, though on smaller lathes it will hit the lathe body. A possibility would be a lathe where the head can be rotated to allow outboard work.

A staple during the yearly tool-making sessions is a simple cove tool, this works better than most other tools but still leaves some tear-out.

Duane’s solution is to use the Mike Hunter tool with the cup cutter. This tool does not require the bevel to rub, and it also allows to work uphill without creating excessive tear-out.

To save time, the beads can be rough-cut with a beading tool. The tools sides need to be ground slightly as unlike with spindle work the beads on the face will curve. However being basically a scraper the beading tool will result in some tear out, so the cup tool will be needed for a final cleanup cut.

Finish the cuts, and sand if needed. Separate the disk from the scrap.

Finishing Part 1

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It is a lot easier to finish the surface now than later when the individual pieces have been cut. An oil finish can be used, but to finish the exposed areas after the cuts will require time. An easier way is to use a lacquer from a spray can, but due to the strong (and unhealthy) fumes a well ventilated area is mandatory to use this finish. Another option is to use sanding sealer which has moderate fumes. Once the sculpture is assembled, a final coat of some other finish (lacquer, shellac etc) and then be applied.

Cutting the Strips

Next the disk is cut into strips. In our example Duane used slightly wedge-shaped strips, but straight cuts can be used as well for a different finish look.

A table saw or chop saw might be used, but the thick kerf and the danger involved cutting the last small pieces do not make those the ideal tools. Duane uses a bandsaw. For the first cut mark a center line down the back of the disk (again the small hole in the center will make this easy), and transfer the line over to the sides. For the actual cut Duane prepared a jig similar to a cross cutting sled, but adapted to the bandsaw. The disk is affixed to the sled using a couple of small pieces of double-faced tape, then cut.

Next sand the freshly exposed surfaces, again checking with a steel ruler for flatness. The thin strips are harder to sand than the larger pieces, so always sand before the next cut.

To cut the wedged-shaped strips, duane uses another jig: a board with wood strips affixed to it to make a tapering jig-like jig. This jig rides against the bandsaw’s fence. For symmetric work, two jigs are required with the taper angle reversed, one for each half of the wood.

Creating the shape

Now the fun part starts: Assemble the strips. Many variations are possible: Varying offsets, reversing every other strip etc. See the photos for some examples.

Duane does this on a board with a slit cut in. The slit allows to draw a witness mark to the underside of the strips to make it easy to find the desired position during final assembly.

Finishing Part 2

Once a pleasing shape has been found, draw the witness line and finish the newly exposed parts of the wood. Finishing now is important, it will make it easier to remove squeeze out during glue-up.

Final Assembly

Now on to final assembly: First glue up pairs of strips, using plenty of clamps and removing any squeeze-out immediately. Angle iron cane be used between the strips and the clamps to even out the clamping pressure. Then glue the pairs together, clamp and clean, and continue until all pieces are glued together. Duane prefers water-based clear drying PVA glue, such as Titebond Molding & Trim Wood Glue.

As the segments are glued together, the resulting structures can have shapes not well suited for regular clamps. Duane devised an assembly table that allows round pieces of woods to be placed in various holes drilled in the board. Machine screws through the wood pieces produce the clamping pressure.

Once all pieces are glued together and have dried, the back is sanded flat, as assembly will always result in some slight unevenness.

A final touch is to devise some method to allow hanging the sculpture to the wall. In earlier sculptures Duane used a keyhole bit in a router to cut a keyhole into the back. But the required depth of the keyhole brings it very close to the surface of the front. So Duane came up with another clever solution: Keyholes cut into round pieces of formica or a similar material. Drill a shallow hole the thickness and with of the formica pieces using a Forstner drill bit, and a slightly deeper hole (but not to deep to come close to the surface on the other side) where the keyhole will be located. Glue the formica onto the opening.

Ideas

The above process allows for a lot of variations to produce different results. Contrasting woods can be glued up resulting in the coves being a different color than the beads. The angle of the slices can be varied. The initial surface treatment can be modified. This is a great project to experiment with!

Handout

Duane Gemelke provided are great illustrated handout that describes the above process. It is available to MWA members who have signed up to the forum in the forums Library section.

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Tops, Chatter and Marbling

March 3rd, 2007

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In todays MWA meeting Alan Lacer shared with us his passion for wooden tops. He started out by showing us a rather large collection of tops in many different variations. Some of these came all the way from Japan, where tops are a favorite past time and also quite a source of competition!

We saw many different tops: Throw tops, chasing tops, howling tops, stacking tops, small (very small!) tops, large tops… The photos in this article show a small part of the collection Alan brought along.

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Alan also brought along two squared platters turned from slate. This have a very nice surface and are well suited running some of the smaller tops in. Slate can be turned, but depending on the composition and hardness that may sometimes be a very tedious process that requires constant sharpening of the tools (as Alan said: don’t turn that grinder off!).

Next Alan showed us how to turn very small tops. For that he used a small piece of Osage Orange, slightly sharpened and hammered right into the head stock of the lathe. Alan being Alan he used a large Skew chisel to turn those small tops, one being less than 1/2” in diameter, the other less than 1/4”. But even smaller tops can be turned (and painted!) as the photos prove (note the ball point pen shown for scale in one of the photos!).

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The rules for a traditional top are simple: good balance and a low center of gravity. But that those rules are not written in stone Alan showed with the next top he turned: a pear-shaped top, designed to stand on the small end of the shape. For this he used a commercially available hard-plastic insert that made the point of the top. Drilling the hole for this point is often a bit frustrating, as the head and tail stock rarely line up perfectly enough for the point to end up exactly in the center. In the worst case the turning tools cane be used to slightly reshape the tip.

For decoration he added some small V-cuts, which he then bruned with a plain piece of wire. He also added some decorative lines with an acid-free pen, which are available in many colors in art supply stores.

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Chatter

Next Alan turned a more traditional top, and demonstrated chattering techniques as a method of texturing. Many turners are familiar with chattering as an unwanted effect whenever vibrations occur during turning.

Best suited for chattering are end grains of dense woods such as hard maple. Nearly any turning tool, held lightly, can be made to chatter, but easiest is the use of purpose-made chattering tools. These usually consist of a piece of thin steel mounted in a tool handle (look out for Duane’s next Tool-Making session! Lightly applied to the surface of the wood, either with the tip or the full flat side of the tool, soon you will here the typical chattering sound. Only this time it is what we are looking for!

The chattered surface can stand as is, or it can be colored. It only takes a moment to use one of the above mentioned pens with a blunt tip to transform the surface. One can even lightly sand afterwards to take the paint of the high spots for yet another effect.

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Marbling

To demonstrate marbling Alan starts by turning some tops specially suited for marbling. These tops consist of two parts: The disk-like body of the top, which is going to be marbled, and an axle. Alan likes to just pressure fit these to parts together, so that in case the axle is damaged it can be replaced without having to discard a nicely decorated body. In this session Alan concentrated on the bodies.

Works starts by drilling the hole into which later the axle will be pushed into. Then he prepares the upper service, and the lower surface as good as possible before parting it off. He then fabricates a jam chuck to reverse fit the disk and finish-turn the future bottom.

The disks, as well as any test paper used for marbling, need to be coated with an alum solution. Otherwise they will accept little or no color in the marbling process.

For marbling, essentially colors are dripped on a bed of a thicker fluid, in this case carrageenan dissolved in water. The colors are then manipulated by means of combs (toothpicks in a piece of styrofoam), brushes or even cat whiskers. Once a pleasing pattern has been achieved, the object to be marblized is carefully deposited on the bed.

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In the case of paper it works easiest by rolling it into the bed to avoid air bubbles. A shake introduced while doing so achieves additional decorative effects.

To dip the disks for our future tops, a dentist hook tool can be pushed inside the hole drilled into the disk. The disk is the carefully pushed into the bed, upper side first. When the disk is submerged, the backwash will color the bottom. A turn of the wrist while submerging the disk creates a nice swirling effect.

The mabelized material is then carefully rinsed in plain tap water, and allowed to dry thoroughly which may take several days. If the results are not pleasing, the process can be repeated one the disks had time to dry.

The bed can be reduced several times, the leftover paint can be skimmed off with newspaper strips before applying new paint.

Marbeling is a fun process. Many kinds of colors, dyes or inks can be used. Various materials are suited to prepare the beds. And the colors can be manipulated using any kind or combination of tools.

This was a fun demonstration, well worth the price of admission.


Handout: Marbeling

Supplies

  • carrageenan (size material)
  • distilled water
  • blender
  • alum
  • foam brush
  • liquid acrylic paints (Golden is a good brand)
  • container for marbling (11/2” to 2”’ deep)
  • eye droppers and/or wisks made from broom straw
  • rubber gloves
  • plastic drop cloth
  • newspaper strips (1” x 10”)
  • optional combs for pattern making

Source for supplies locally

  • Wet Paint at 1684 Grand in St.Paul.

Practice paper

Ingres Pastel paper in white (available at Wet paint).

References

Books
  • The Ultimate Marbling Handbook by Diane Maurer-Mathison

  • How to Marbelize Paper by Gabriele Grunebaum

Articles
  • Mary Thouin did a two-part article in the Fall 2002 issue and Winter 2002 issue of American Woodturner

  • Jacques Blumer, page 40 of American Woodturner Fall 2003

Links

Lace Bobbins

February 6th, 2007

Gosh, I can’t believe it has been more than half a year since my last entry here! A lot happened in my life since and time has become a more scarce resource. I missed some great demonstrations at the MWA, though I did manage to attend Jim Jacobs great demo in November on how to make ornamental birdhouses. Though I failed to report about it, I did learn a lot and put it to great use. Jim made kits available at a low price, and I turned several birdhouses for friends and families.

Lace

But back to today: Todays MWA meeting was all about lace, and how to make lace bobbins. The meeting started with guests from the Minnesota Lace Society giving an intro about lace making, what tools are required, especially the lace bobbins. Like our turning tools, lace bobbins come in many different variations, depending on what technique is used and what country and region they come from. And like turners, lace makers have their preferences about how their tools should look and feel. I will attach some scans to this entry that point out some basics, some examples for lace bobbins, and also some references.

Bone as a material

Next Lisa Botten demonstrated how to turn a lace bobbin. While many dense hardwoods can be used to make lace bobbins, Lisa chose bone for todays demonstration. She uses blanks cut from a cows femur bone. To prepare the raw bones she cuts of the top and bottoms to expose the mark inside, then she repeatedly cooks the bones until the water stays clean and most of the fat has been cooked out of the bones. Then she selects the parts of the bone she will use for her blanks. Some areas in the bone have a more punky structure which is less suited for this purpose.

She cuts the blanks using a vertical bandsaw, though others methods may be used too. Extra care must be taken to guarantee a safe cut due to the shape of the bone.

Bone is a brittle material and requires very sharp tools. It should be mounted between centers with as little pressure as possible. Light cuts, supporting the work with fingers, are paramount. Other than that the technique is very similar to spindle turning, just everything en miniature. Lisa turned the entire bobbin using just a small skew chisel, a perfect too (once mastered) for the job.

All in all a fun presentation, thanks to all who made it possible!

Bobbins worksheet

Here are some Bobbin-making instructions and samples provided by our guests from the Minnesota Lace Society.

Lace Making Bobbins

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Lace Making Bobbin: A hand-held tool used in a particular lacemaking technique to move thread in various patterns. Bobbins come in a wide variety of shapes and weights, depending on their regions of origin and the thickness of the thread used to make the piece of lace. Bobbin lace is made with 4 to 400+ bobbins of thread at a time, unlike knitted, crocheted or tatted lace which uses one or two threads at a time.

Bobbins must:

1) Have a slim neck around which the thread is wound/stored.

2) Be of sufficient weight at the end of the shank to keep thread taut enough to keep under control on a special pillow, but not so heavy as to risk breaking the thread.

3) Be designed so that the lacemaker’s fingers do not touch the thread.

4) Be finished so as to not catch or discolor threads.

5) Feel comfortable in the lacemaker’s hands.

How-to Resources
  • Son of Skew DVD by Alan Lacer
  • Woodtuming in Miniature by Ian and Nina Wilke, Crowwood Press, 2001.
  • Kenn Van-Dieren. Website: www.bobbinmaker.com or Kennr@bobbinmaker.com. Kenn has a book out on how to turn bobbins as well as a catalog of lace tools he makes.
  • VanSciver Bobbinlace. Website: www.vansciverbobbinlace.com for a catalog of shapes, tools, information and Kenn’s book.

2/6/07 L. Fumuso

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Click here for a high resolution version of above image.

Tool Making Meeting

June 10th, 2006

Todays MWA meeting was at John Magnussen’s great place out in Buffalo. He also invited us to visit his private gallery, and there was some absolutely stunning work to be seen!

But back to the meeting: Duane Gemelke gave a great introduction to tool making, followed by an opportunity for us to make our own tools. Many type of tools could be made:

  • Texturing/Chatter tool
  • Straight and angled hollowing tools
  • Captive ring tools
  • Diamond tool
  • Small detail skew
  • Small gouge-like tool

and a number of other shapes that can be easily ground from a round tool steel. And of course tool handles for the newly-made tools. Duane gave a rundown how to make each of these tools, then we started making whichever tools we liked. Duane and several MWA members were at hand to help.

I will not go into the details of making the specific tools as it depends a lot on the available materials and tools. Instructions for many tools can be found on the internet. But there were a number of tips and jigs that were very helpful and which I list below.

Hidden jaws in Talon chuck

This was a very valuable tip: If you remove the jaws from a Talon chuck, the now exposed ‘jaw holders’ (for lack of a better name) can be used as jaws for small-diameter items! In the tool making session we used it to chuck the tool steel to work on the front.

Splitting pipe fittings into ferrule blanks

Copper pipe fittings are a popular base material for making ferrules. But the have to be cut in half, in the plane where in ‘real life’ the pipes would meet. Thus each pipe fitting provides material for two ferrules. Duane had a very helpful jig for this: 2 Wooden blocks with a square cross section, one end each turned to a diameter so the pipe fitting would just fit over it. One of these blocks on each end of the pipe fitting, the blocks clamped down to the table, and there is a handy holder to hold the pipe fitting while cutting it.

De-burring jig

The above splitting of the pipe fittings leaves one end of each ferrule to be with a rather sharp burr. Duane had a special-made chuck for the ferrules: A block of wood turned round on one end to fit into a chuck, the other end turned down to just fit about 3/4 deep into the ferrule. This end is then cut with a thin blade about halfway towards the chuck end, and a second cut at a 90 degree angle. Now with the ferrule mounted, a screw is screwed into the center from the front, expanding the four quarters slightly and securing the ferrule.

Now with the lathe at slow speed a file can be used to true the swan edge and round over the outside edge. The inside edge can be de-burred using a small tool. As copper is relatively soft pretty much any turning too may be suited for this.

While on this jig one can also sand and polish the surface of the ferrule if so desired.

Tool handle turning jig

It is a lot easier to drill the tool handle blank for the tool steel before turning it. But that makes it tricky to mount the blank between centers. A small piece of wood as adapter between the blank and the life center makes this easy. One end of the wood is turned to just fit into the hole in the blank, the other side flat with a small indentation in the center to rest on the tip of the life center with the flat resting on the cup makes that a lot easier. In addition the blank end has a second radius turned on it that just fits the ferrule. That serves as guide for how far down to turn the blank, and the ferrule can be test-fitted on the blank without having to remove it!

Book List

May 27th, 2006

Over at BT3Central.com a nice fellow named Keith went through the archives and compiled a list of woodworking books recommended frequently. Thanks! Just in case I made a copy here.

Whole lot of folks recommended these books

  • Table Saw Magic by Jim Tolpin ISBN: 1558706771
  • The Table Saw Book by Kelly Mehler ISBN: 1561584266
  • Woodworking with the Router by Bill Hylton and Fred Matlack ISBN: 0762102276
  • Bandsaw Handbook by Mark Duginske ISBN: 0806963980
  • The Bandsaw Book by Lonnie Bird ISBN: 1561582891
  • The Complete Book of Woodworking, Published by Landauer ISBN:1890621358
  • Getting Started in Woodworking by Aimee Ontario Fraser ISBN: 1561586102
  • Measure Twice, Cut Once by Norm Abram ISBN: 0316004944
  • Understanding Wood Finishing: How to Select and Apply the Right Finish by Bob Flexner ISBN: 0762101911

Individual recommendations with poster that recommended at the end

  • Tage Frid Teaches Woodworking 1&2 ISBN: 1561580686 esp. vol. 1 – jethro
  • Router Basics by Patrick Spielman ISBN: 080697222X –Anthony
  • The Router Book by Doug Geller ASIN: 069611092X –Anthony
  • The Complete Guide to Sharpening by Leonard Lee ISBN: 1561581259 - milanuk
  • Turning Pens and Pencils by Kip Christensesn ISBN: 1861081006 – S. Muth
  • Workshop Math by Robert Scharff ISBN: 0806958022 – John Parker
  • The Handplane Book by Garret Hack ISBN: 1561587125 – Bob Crosley
  • Choosing and Using Hand Tools by Andy Rae ISBN: 1579902944 – Bob Crosley
  • The Complete Guide to Easy Woodworking Projects by Black and Decker ISBN: 1589230930 – Woodnut
  • Woodworking: The Right Technique: Three Practical Ways to Do Every Job – And How to Choose the One that’s Right for You by Bob Moran and Nick Engler ISBN: 0762102284 -jriechel
  • Proven Shop Tips by The Taunton Press ISBN: 0918804329
  • Decorating with Architectural Trim work – Planning – Designing - Installing By Jay Silber ISBN: 1580110789 – Steve
  • Woodworkers Hand Tools: An Essential Guide by Rick Peters ISBN: 0806966610 – Bob Crosley
  • Restoring, Tuning and Using Classic Woodworking Tools by Michael Dunbar ISBN: 080696670X
  • Router Magic: Jigs, Fixtures and Tricks to Unleash Your Router’s Full Potential by William Hylton ISBN: 0762101857 – oakchas
  • Crown Molding and Trim – Install It Like a Pro by Wayne Drake ASIN: 1581125941 – wild bill
  • Make Your Own Electric Guitar by Melvin Hiscock ISBN: 0953104907 – Tundraman
  • Chests of Drawers by Bill Hylton ISBN: 1561584223 - istvan

Video’s mentioned while looking for books

  • Master Your Table Saw Video by Kelly Mehler -sillygoose
  • Frank Klausz on Biscuit Joinery
  • Mastering Your Table Saw by Taunton Press ASIN: 6302706262 - sillygoose

Wood Finishing with Allan Lacer

May 6th, 2006

In today’s MWA meeting world-renowned turner Alan Lacer talked about wood finishes, specifically how they apply to wood turnings. It was a whole-day meeting at Jim Sannerud’s shop in Ham Lake. It has to be said that Jim went above and beyond to make this an enjoyable day, many thanks to him!

I was utterly amazed by the entries for the egg challenge. All the entries did deserve a price, they were just awesome. Great work!

But let’s get to todays topic: wood finishes for turners. Below a (brief) summary of todays session.

Preparing the wood

Finishing the wood starts with the last cuts on the lathe. When turning for example a bowl within one revolution on the lathe the wood will be cut with the grain in some sections, and across the grain in others. That can easily lead to tear out, which is not easy to sand away. Also excessive sanding can bring a piece out of round, as the sand paper cuts different across and with the grain.

Sharp tools and a gentle cut can leave a surface that doesn’t require much sanding. A bowl gouge with an Irish grind (many variations are known as fingernail grind, Ellsworth grind etc.) can be used for a light shearing cut or shear scraping by using the sides of the tool presented at a steeper than usual angle.

Another option is to use the burr of a scraper with the scraper on edge so that just the burr cuts at an angle to the wood. For a finishing cut the burr of a grinder is usually to aggressive. For finishing Allan takes the burr of with a honing tool, then creates a new lighter burr with a burnisher.

Fine paper-thin shavings are a good indication of a light cut suited for finishing. These cuts are not very hard, learning them will make finishing much easier.

Sanding

Choosing the right sand paper will make this job much easier. Alan’s favorite is a purple ceramic-based sanding paper from 3M, currently only available commercially or in large quantities. Another choice is the 3X paper from Norton. I have been using that paper exclusively for the last 2 years, it is much superior to other papers I have tried. It doesn’t load easy and seems to cut for a long time.

When sanding on the lathe avoiding sanding rings is important. For bowls using and angle-drill with a cup (soft or hard) and a sanding disk makes sanding on the lathe (with the lathe running relatively slow) fairly easy. And the two opposing motions help avoid sanding rings. Finishing up to (depending on wood) 220 to 380 grid leaves a surface suited for finishing.

I do not have a angle drill and use the papers ‘by hand’ with the lathe running. That works, albeit slower. To avoid visible sanding rings using this method one has to go to a higher grid, depending on the wood I typically go to 400 or 600 grid.

When sanding spindle work, end a sanding grid by stopping the lathe and sanding larger flat sections with the grain. That avoids the most visible sanding rings.

Safety: Sanding generates fine dust that is quite hazardous to your health. Prolonged exposure can even trigger allergies. Collect the dust at the source! I use a section of flexible metal dryer duct connected to my dust collection piping. The duct can be aimed at wherever the dust is produced. This is an efficient and low-cost method.

Finishes

Choosing a finish is not easy, there are many factors to consider. If in doubt, try a sample piece, especially with finishes that are not easily removed. Some of the deciding factors are:

  • Desired appearance: Glossy or flat, finishes that leave a film or are ‘in’ the wood, color
  • Ease of application: Wipe on (on the lathe or off), spray finishes etc., required equipment
  • Speed: Drying time, curing time, time between re-application
  • Repairability, reversibility, renewability, durability
  • Health concerns

That last point requires special attention. Pretty much all finishes available today are save for contact with food when fully cured (which can take some months for certain finishes). Salad bowl finishes or finishes for use on toys are nothing but re-badged common finishes. A cured finish leaves behind substances that are actually used in food production (mineral oil, plant-based oils, shellac, wax), or substances that are inert (film finishes such as polyurethane or varnish).

However during application the solvents used in most finishes are toxic. Nitrile gloves and in some cases respirators are strongly recommended. Environmental concerns (solvent release into the atmosphere, proper disposal of left overs) may further sway you to avoid certain finishes.

Safety: Note that rags used to apply most finishes are a fire hazard due to the heat generated during the drying process! Keep used rags outside, or in a water-filled bucket. Do not simply throw them in the trash!

Drip test

Many finishes these days do not list ingredients, making it very hard to predict their performance. Even worse, some finishes have a limited shelf life (sometimes as little as six months) but do not list a date.

A very easy way to evaluate a finish is a drip test: Apply a few drops of finish on a piece of transparent plastic. From this you can tell drying time, color, hardness when dried and or cured (not the same). This often allows to determine likely ingredients of a finish, and more importantly gives you data for some of the basic parameters of a finish.

Oil finishes

Mineral oil (which is suited for human consumption) is frequently used for food bowls and cutting boards. It is transparent and does not change the color of the wood other than the wetting effect common to all oils, which often highlights the beauty of the grain. Mineral oil penetrates the wood and helps it resist moisture. However it does not cure and requires regular re-application. Mineral oil is available at grocery stores.

Nearly all other oils used in finishing cure eventually. However the do not build up significantly, so they do not tend to create a finish with a deep luster. Drying time varies but is generally very slow.

Tung oil is a favorite among the oils. It comes from the chinese tung nut, and has a very unique scent. Application is simple: flood the surface, let it penetrate for a while, then wipe off the excess. It does cure, and is used in many coats can create a very slight build up. It has a yellowing effect, which makes it less popular for light colored woods. Shelf life is almost unlimited. Care must be taken when purchasing tung oil. Many products using the name tung oil or even pure tung oil contain additional ingredients or sometimes no tung oil at all.

Walnut oil is another favorite. Cheapest source is the grocery store. It is a bit lighter in weight then tung oil and does not build up.

Linseed Oil (or BLO, Boiled Linseed Oil) is another commonly used oil product. It has a lot of tradition, because it was one of the most commonly available oils. But in my humble opinion it is not a very good finish. Protection value is minimal, durability low. Though it may be suited for mixing with other finishes (see below).

There are some specialty oils available for finishing, such as polymerized tung oil (a favorite for gun stocks) or polymerized linseed oil. These oils cure much faster than their non-polymerized base materials, and may even build up a finish. However they are quite expensive.

Film building finishes

Varnish

Varnish is another very traditional finish. It is durable, alcohol and water safe. Traditionally it comes in soft, medium and hard varieties, and sometimes with additional properties such as UV protection etc. It is a film finish that stays on the wood and builds up with repeated application. One of the problems of Varnish is that today it has become a synonym for a very large family of finishes with vastly different properties. Many manufacturers do not list ingredients, and it is impossible to tell if they started with a good quality varnish or not.

According to Allan one of the better brands with consistent high quality varnish is Waterlox.

Oil-Varnish mix

Oil-Varnish mixes have been popularized by Sam Maloof. They attempt to combine the ability of oils to pleasantly highlighting the grain with the protective qualities of varnish while trying to avoid it’s sometimes plasticky ‘on the wood’ appearance. It is available in many varieties, containing unknown quantities of ingredients and solvents.

Allan recommends mixing your own. The traditional Sam Maloof formula is pretty well known:

  • 1 part Boild Linseed Oil (for it’s drying ability)
  • 1 part pure 100% tung oil (for it’s beautification ability)
  • 1 part high quality solvent/oil(!) based varnish or polyurethane

Spar varnish is not suited as it is to soft. An example for a suitable varnish is Behlen’s rock hard table top varnish.

The above mix results in a pleasing and durable finish, suitable for items handled frequently. At least three coats are recommended, wait at least two days (better two weeks) between coats.

Lacquer

Lacquer is a finish that creates a clear, very high-gloss film finish. It dries extremely fast, in fact consumer-grade Lacquer typically contains retardants to make it dry a little slower so it is easier to work with.

It is liked by many turners as it is easily available, fast to use with predictive results. The downsides to Lacquer are the strong fumes it creates during application and while curing. Some people also do not like it’s appearance, which can be cold.

Water-base finishes

This group of finishes mostly consists of water-based (or water-borne) polyurethane. These finishes dry fast with little odor. But the film finish tends to leave the wood cold, and it tends to build up with a bit of a haze. However these finishes are a relatively recent addition to the finishing market, and given fast-paced development they hold promise for the future.

Shellac

Shellac is a great finish that many think will have a renaissance. Shellac comes in flakes produced by the female shellac bug for protection. It is available in various colors from very light blond to a fairly dark color, all also available de-waxed. Once the flakes are dissolved in denatured alcohol, shellac is ready to use.

Shellac has a lot of great properties: It can go above or below any other finish (the only finish that can do that), is easily applied and repaired, new coats slightly dissolve and bond with previous coats. It creates a great looking finish which can be buffed to a mirror sheen.

Shellac also is a finish that minimizes vapor penetration into wood, preventing wood from moving.

Downsides are that it only tolerates moderate handling, which makes it unsuited for items such as pens. However most commercial pen finishes contain mostly shellac and wax, because they are easy and fast to apply with a great appearance. But they are not durable enough for day to day use.

Also once shellac is dissolved in alcohol, the shelf live is approximately six months. The alcohol changes the chemical makeup of shellac, and after a certain period it will no longer cure properly.

In some cases the color of shellac can also be a problem, though the blond varieties are very lightly colored and typically just add a bit of warmth to the wood.

For starters Allan recommends to get some light and some dark de-waxed flakes. Colors in between can be achieved by mixing these varieties. Mixes suitable for turners are 1.5 to 2 pound cuts, meaning 1.5 to 2 pounds of shellac per gallon of alcohol. Obviously that is a rather large quantity, so divide into smaller equivalent quantities. 4 ounces to a pint also results in a 2 pund cut.

A great french polish type finish that is very fast to apply and dry can be achieved by mixing shellac with oil (tung oil, BLO etc), shellac in an amount equalling about 3/4 of a jar of baby food with about a table spoon full of oil. Application is much like a friction type finish: use a lint-free cloth with very little texture and apply the mix on the wood spinning in the lathe. It builds a very nice sheen in a hurry and dries to the touch within seconds.

Wax

Wax is the closest to no finish at all. It is easy and fast to use, but does not stand up to use making it suitable only for decorative pieces or to give a piece that extra sheen to facilitate sales by applying on top of other finishes.

The best of the waxes is carnauba wax. It is fairly hard and at least somewhat durable. However it leaves a slightly cold looking finish. Beeswax leaves a warm finish, but is very softy. For this reason folks sometimes mix waxes, for example by adding a bit of bees wax to carnauba wax. The waxes can be mixed by heating in a double boiler, or the can be made into a paste by adding turpentine.

Common floor waxes can also be used. However one should make sure they do not contain the solvent toluol, as that can react with other finishes to make them milky in appearance. There are also health risks involved with toluol.

No finish

Some oil rich woods can be polished to a great luster without the use of any finish at all. Cocobolo is one such wood, and in fact finishes do not easily bond with cocobolo because of it’s high oil content. Another wood that can come out great without finish is bloodwood.

Finishing the Finish

The appearance of some finishes can be further improved by polishing the finish, though care must be taken to not work through the finish. Finishes should be thoroughly cured (and therefore hardened) before polished. Traditionally compounds such as Pumice Stone & Rotten Stone were used for polishing. These days however many polishing compounds found in automotive departments offer a easier and faster to use solution, though it requires a little experimentation as the abrasive quantities of such compounds are not known until tried.

Another buffing solution are the Beall buffing wheels.

Sometimes it is also desirable to flatten the appearance of a finish. For this Allen recommends a steel-wool like synthetic product from Germany which is making an appearance in the US market.

Lidded Boxes

April 11th, 2006

Tonight a very entertaining Brad Hubert introduced us to the art of box turning at the monthly MWA meeting. Brad has several hundred boxes under his belt. It was interesting to see the different approach of a production turner.

Wood choices

Brad makes all his boxes from wood ‘harvested’ in his neighborhood. Most native woods can be turned and also turned into lidded boxes. He starts out rough turning long sections of green wood. Once round, he uses a bandsaw to cut them to the desired lengths for the lids and bottoms, careful to keep the pairs together for best grain alignment. Sometimes he then also ‘rough hollows’ the pieces to relief stress and accelerate drying, then he puts them aside for several months for drying.

My wood pieces are typically smaller and only big enough for a single box. I start between centers, turn the wood round, add a rebate to both ends for later chucking , and cut the top and bottom appart with a saw or a thing parting tool. Brad rounds over a long section of wood and cuts it on the bandsaw. He also foregoes the rebates on the lids and just chucks in the entire top, which saves material if you have a big enough chuck.

Inside: the top…

The top usually being not that deep he just uses a scraper to quickly hollow it out. Then he uses a special side-ground scraper to cut the rebate into the lid that will later fit over the bottom. He adds a very light chamfer to the inner edge. At that point the inside part of the lid is done. Brad does not sand them, he says with sharp tools and sufficient practice the finish obtainable by a scraper is fine enough to leave.

…and the bottom

The he chucks in the bottom. He starts hollowing by making a small dimple into the center, then he uses a long drill epoxied into a handle to drill out the center. He has permanently marked the drill in inch increments (I meant to ask how, seemed like he turned in thin lines on a metal lathe. I have to ask him next time I see him). These markings help him to gauge the desired depth (Brad reminded us several times that the inside of a box MUST be smaller than the outside…). Then it is back to gouge and scraper to hollow out the bottom.

Brad briefly mentioned the back hollowing method, a method to very quickly hollow out wood which amongst others is featured on the (scary) Richard Raffan videos. It is hard to master, and being so quick it is very easy to go to far…

Next Brad uses a peeling cut with a skew to cut the rebate onto which the lid will fit. Here patience is important. By repeatedly cutting, stopping the lathe and test-fitting the lid the correct size is found. As little as 1/1000th of an inch is the difference between a snug and a loose fit. At least for now I prefer a snug fit (it can always be loosened up later), that makes turning the outside of the lid easier. But if it does get too loose a couple sheets of toilet paper help here. Even Brad with his box turning experience needed several attempts. I was relieved to see that he stops the lathe for test fits, unlike a practice shown on some professional turning videos. A trick to use here is to cut the rebate with a very slight bevel. Once the lid starts to fit over the rebate the rebate is carefully squared up.

The outside

At this point the inside of the box is done. The lid is attached. Brad additionally secures it with a strip of masking tape (a very good idea!). He turns the top of the lid to the desired shape, then works his way down the side and in the process the masking tape is turned away. While working on the top light cuts are essential, any catch will most likely send the lid flying.

We do that by magic…

At this point the box is finished. Or ist it? Brad kind if glossed over the detail of turning the bottom of the bottom part and removing the rebate used for chucking. We do that by magic he says… That was a little disappointing as that part gives many beginners pause. But he did explain the basics briefly: One starts by chucking up a piece of scrap wood. A rebate is cut into it, into which the top of the bottom will fit snugly. As before, patience is the key to get the size just right. The bottom is fit into it, then it can be turned. The problem here is that the bottom can’t easily be secured with masking tape like the lid, and also that the bottom is typically deeper than the top, so there is more lever action while turning. I typically use the dead center to help support the work as long as possible, and by making very light cuts.

Finishing

As with most wood projects many kinds of finishes can be used for wooden boxes. Brad prefers Danish Oil which he applies off the lathe in two or three coats. Danish Oil is very easy to work with and almost fool proof.

Smaller boxes are often used for jewellery, so Brad using flocking materials to finish the insides of such boxes.

Belt Change on a Harbor Freight 34706 Lathe

March 30th, 2006

Today I changed the belt on my Harbor Freight 34706 Lathe. That was a lot harder than it should have been: The clearance between the pulley and the cast-iron housing was about 1/4”, not enough to get the new belt through without damaging it. So the pulley had to come off for the belt change.

The outer half of the two part pulley (it is a variable diameter pulley to allow for speed changes) is secured on the axle with a c-ring and two set screws. Problem was that the pulley was stuck on the axle. I guess a pulley puller or maybe some heat could have helped the situation, but alas I had neither available.

I started tapping the pulley with a mallet, but after a few taps I realized that this would probably damage the bearings. I ended up wedging a piece of wood between the pulley halves, using the speed-control handle to apply some pressure, release, rotate the pulley a bit and repeat. It took about 15 minutes, but the pulley came off fraction by fraction.

I cleaned the axle and the opening in the pulley by sanding them lightly, and applied a small amount of White Lightning bicycle grease on the axle. The pulley went together a lot easier (yes I remembered to put the belt in first), and hopefully next time this procedure will be a lot easier.

Egg Turning

March 8th, 2006

Yesterday MWA meeting was about turning eggs, and unlike my Easter Eggs from last year these were solid. Dan Rominski gave the demonstration.

Wood choice and preparation

Pretty much any kind of wood of appropriate size can be used to turn eggs, though it should be reasonable dry to avoid later splitting. The firewood pile might yield some useable pieces for this endeavor. To prepare the wood mount it between centers and round it over with a roughing gouge. Then cut a rabbet on one end so the wood can be mounted in a chuck. In this case a peeling cut with a Skew made quick work of this.

Turning the egg

All the remaining work can be performed with a large Skew, only for the final part off a smaller Skew comes in handy. For safety the tail stock should be engaged for the rough shaping. A blown-out egg can be used to help judging the developing shape. Once a rough egg shape has developed and some of the waste wood has been turned away to have plenty of room for the tool, the tail stock is removed. The egg shape is further refined, leaving just enough wood at the head stock end to drive the egg. Once the shape is fine and the surface smooth, the egg can be sanded and finished right on the lathe. Depending on the smoothness of the cut, start with 150 or 220 grid sandpaper, and work up to 600. In our demonstration the egg was then finished with a mix of Shellac and mineral oil. It goes on very easy and can be polished similar to friction polish right on the lathe. Now it is time to ‘cut the egg loose’. Using a smaller Skew carefully turn away the remaining connection to the head stock end. Once the egg is free some quick sanding and finish touchup at that end and the egg is finished.

Parting thoughts

Turning eggs is a fun project, and a great opportunity to hone the Skew skills. Alan Lacer’s Video/DVD The Son of Skew (which has been on my want list for some time) further demonstrates how it is done.

Various ways of chucking

February 7th, 2006

At tonight’s MWA meeting Jim Jacobs and Steve Tiedman demonstrated many ways to chuck wood onto a lathe. Drive centers, face plates, scroll chucks, even a vacuum chuck were presented. While I knew many of these from the various catalogues and web sites, it was great to see them in person and to get comments from people who have used them.

Of special interest to me were the various home-grown recipes. For example Steve showed how a low cost old fashioned dead center could be modified and used as a drive center. It is similar in performance to a Sorby steb center, but at a much lower cost.

For small objects it sometimes is sufficient to just cut one end into a rough taper. That can then directly be mounted into the morse taper, no chuck required at all!

Another method: turn a taper to fit the morse taper, with a plate on the thick end. Mount into the morse taper, drill a small hole, glue in a nail and fashion the head of the nail into a point. This can be used as drive center for small projects or spindles. It is very save, should the wood catch it would just stop spinning. It is also a great training tool to learn to work with light pressure.

To turn the body part of miniature birdhouses, Jim fashioned a mandrel. While for the body of a miniature birdhouse could simply use a dowel and drill a hole through it, it is hard to get that hole perfectly concentric. Jim’s mandrel solves that problem: It is square on one end to allow it to quickly mount into a scroll chuck. The remainder is turned round to the diameter of the hole drilled into the future birdhouse body. The other end of the mandrel has perpendicular cut through the center. The tail stock will slightly pry the wood apart, and thus securing the body of the birdhouse on the mandrel. A simply but effective solution!

To turn the perches for those miniature birdhouses Jim has another trick: A block is chucked into a scroll chuck, and a hole drilled into the wood block, easiest with a Jacobs chuck in the tail stock as Steve demonstrated. Now a dowel, slightly tapered is pushed into the wood block. Et voila, a simple way to chuck very small items.

Another MWA member demonstrated how simple (and cheap!) PVC endcap from the plumbing department can be mounted onto a chuck. Wrap some non-skid fabric from the home department around it, and it can be used to reverse-chuck a bowl to finish most of the bottom.

Jim used another type of endcap to turn spheres. That endcap was about 5” in diameter, and the closed end has a square protrusion, which fit perfectly into a chuck. A spherical body would fit perfectly into the open end. To support the tail-stock end, Jim removed the point from a live center, leaving just the cup. To prevent the wood from marring he used a hose washer between the cup and the sphere.

Another really helpful gadget: When turning a tenon for a scroll chuck, I like it to be as big as possible while at the same time being not so wide that the jaws protrude sideways from the chuck to reduce the danger of injury. Also for some types of chucks the tenon should be sized such that the jaws of the chuck form a circle, that maximizes the surface area on which they grip. I used to always set the chuck to the proper width, measure it with calipers and use that to gauge the size of the tenon. Jim and Steve had a handy little jig to make that easier: made from wood it looked like one end of an open ended wrench, the width of the opening being the perfect width for the tenon. And when made from wood of the proper thickness it can also be used to gauge the depth of the tenon. It should be deep enough to allow for maximum surface area, but it should never bottom out in the chuck. Handy little gadget, I’ll make one next time I’m in the shop!

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Yours truly also got invited to show the Longworth Chuck. If you came to find out more about that chuck, click here to see my original post along with links to instructions.

All in all another very informative meeting. I learned a lot, and will have to visit the plumbing department soon!