Plexitone Pen Finish
Plexitone Pen Finish Overview: In the December 2008 issue of Lathe Talk, I reviewed a very old home made finish made from Plexiglass and Acetone (known as Plexitone), that's becoming popular again with woodturners for finishing smaller items on the lathe. Plexitone can also be used for stabilizing small wood blanks and as a dipping finish, when thinned to the proper viscosity.
As you recall from last month's issue, Plexitone is not an easy finish to work with, in fact it can be a bear at times. However, if you take your time and experiment with different viscosities, it can produce an amazingly durable and lustrous finish for smaller woodturning projects like pens, bottle stoppers, letter opener handles, small boxes and even small bowls.
Many woodturners are now experimenting with Plexitone as a finish for their writing pens. If you would like to give Plexitone a go, the first thing you need to do is make your master solution (details in 12/08 issue of Lathe Talk). Once your master solution is ready to go, use a wooden tongue depressor to remove some of the master solution and place it into a clean glass jar, or a metal can with a tight fitting lid.
This will be the container that you will use for mixing your Plexitone pen finish. To make your Plexitone pen finish, thin some of the Plexitone master solution with Acetone until it's half way between the viscosity of thin and medium CA. This will be your starting point. Thicker Plexitone solutions can also be used, you will have to experiment and see what works for you.
Always test your Plexitone pen finish on some scrap wood barrels before applying it to your pen. Once you get the viscosity right, you can store the Plexitone pen finish for several months and use it as necessary. Here is the protocol I use for applying the Plexitone pen finish to writing pens.
20-Step Plexitone Pen Finish Application Protocol
- Sand the barrels to P400-grit. Remove any residual dust with compressed air, or wipe the barrels with a clean paper towel.
Pen barrels should be sanded to 400 grit.
- Apply Acetone on a small bit of paper towel to clean the surface and remove any dust from the pores. The barrels must be clean and dry before applying the Plexitone pen finish.
- Double check that no circular sanding scratches are left on the surface. If any are found, re-sand to remove them and then re-clean the barrels before proceeding. This finish will make tiny sanding scratches look like the Grand Canyon, so get the best surface possible before proceeding.
The finished barrels after sanding
and cleaning the barrels.
- Remove the sizing bushings and mount a sacrificial set for finishing. This step is optional, but it is a good idea to keep your primary bushings clean and ready to go for the next project. If you do not have a sacrificial set of bushings for your pen, proceed with your primary set. When you're finished with your pen, place your bushings in a small jar of Acetone and let them soak overnight to clean off any Plexitone residue.
- It's also a good idea to place a drape over your lathe bedway, unless you fancy cleaning up spills. A clean shop towel, or paper towel works well for this, as does a small scrap of thin plywood. Be sure to clean off any dust or debris from the lathe before finishing your pen. Any dust left on the bedways may get kicked up and into your finish when you're applying it, so stop and clean up before proceeding.
- Plexitone pen finish is usually applied whilst the lathe is running, except when used as a dipping or soaking finish. I typically apply Plexitone to pen barrels around 1,200 RPM. The exact speed is not critical, but no more than 1,500 revs should be attempted, or the finish may dry before you can evenly coat the barrels.
Thinned Plexitone pen finish ready for application.
- To protect my fingers when applying this finish, I use a pair of 4H laminated chemical resistant gloves with the fingers cut off to make a small finger glove. Only the last two knuckles of my thumb and index finger are covered for safety.
4H chemical resistant finger gloves are used
for applying the Plexitone pen finish.
- Use a small folded piece of clean paper towel to apply the finish. I like to take a clean white towel and fold it into fourths and then cut strips off the end into 3/4" wide sections. I call these applicators finishing "padettes." Do not use paper towels with coloured designs, as the colour may transfer onto your barrels during finishing.
Applying Plexitone pen finish.
- Apply a small amount of Plexitone to the end of your padette. Start at one end of the blank and in one single smooth pass, run it down to the opposite end of the blank. You should overlap the barrel ends slightly to insure that you cover the entire barrel. (The bushings are easily cleaned later).
- Reapply some finish and repeat in the opposite direction. Your speed up and down the barrel should be fast, but not too fast. You want a smooth even lay down, so adjust your speed as necessary for a smooth continuous flow of finish onto the barrel. This takes some finesse, but it's easy to learn.
- Keep reapplying the finish in opposite directions until you build the finish to an acceptable level. We all have a different idea of what "acceptable" means, so I'll just say that I apply the finish for three minutes, give or take. This is somewhere around 25 to 30 coats of finish. The total application time varies, depending on the finish viscosity and my lathe RPM's.
- This finish will dry quickly, so each pass up and down the barrel should be over the previously applied dry finish. If your barrel is still sticky when you apply the next layer of finish, it may be too thick for fast passes. If so, simply wait a few seconds in between each pass, or thin it down slightly with more Acetone and try again. As I mentioned, this finish requires practice, so start out on some scrap blanks first and get your protocol down pat before you risk an expensive blank.
- After you've completed your last pass, let your lathe free spin for several minutes. This allows the Plexitone pen finish sufficient time to dry. Three to four minutes is usually fine, but this will vary with the viscosity of the finish you applied. Take this time to clean up a wee bit and get your Micro-mesh abrasives ready to go.
- I prefer to wet sand Plexitone with Micro-mesh abrasives. If you achieved a good lay down (smooth finish on barrels), you can start sanding with 2400-grit. Keep your lathe revs set at 1500 RPM. I never use the 1500-grit and 1800-grit Micromesh on a wipe-on Plexitone finishes, because they're too aggressive and will cut right through your built up finish.
Wet sanding the Plexitone with Micromesh abrasives.
- Use water to lube your Micro-mesh when wet sanding and frequently dip your folded sheet into a dish of water. This does two things, it cleans the residue off the face of the abrasive and it forces you to slow down when sanding your barrels. Use very light pressure when sanding, only a tiny amount of pressure (no more than enough to place the abrasive against the barrel and move it along) is necessary. If you press to hard, you will sand right through your finish.
- Move through each Micro-mesh grit without skipping steps, from 2400-grit through 12,000-grit. When you change grits, stop the lathe and wipe the surface off with a clean bit of wet paper towel. This will remove any residual dust and give you the opportunity to examine the surface. After you get comfortable with this finish and how it sands, you can sand all the way through without stopping, but you still need to remove any residual dust with a wet paper towel.
The completed Plexitone finished pen barrels
after wet sanding to 12,000 grit.
- Once you've completed your Micro-mesh sanding, you're ready to apply a microcrystalline wax like Renaissance wax onto the barrels to prevent fingerprints from showing on the high gloss surface. Take a clean padette and apply a small amount of wax onto the barrels with the lathe off. Wipe off any excess, turn on the lathe, and lightly buff to a brilliant gloss. Take care to press lightly when buffing, or you will strip off the microwax.
- After you've completed waxing the barrels, you're ready to remove them from the mandrel. Take a small single edged razor blade and lightly run it around the end of the barrels where they meet the bushings. Be careful to not damage your barrels. Use a magnifying headset if necessary and proceed slowly. There is usually a small amount of finish on the end of the barrels/bushings and you need to score this before removing the barrels, or you may damage the barrel finish.
- Once the barrels are removed, lightly sand the end of the barrels with 600 or 800-grit abrasive to remove any sharp edge transition on the end of the barrels. Take care to keep the end of the barrel straight across when sanding. An easy way to do this is to tape a bit of sandpaper to your lathe bed, place the barrel against the abrasive, and rotate it in small back and forth circles once or twice.
- When you've completed the barrel end sanding, your pen is ready to be assembled. This is far from an easy finish, but you just might come to like it once you learn how to use it. Good luck and happy experimenting!
Thicker Plexitone finishes may be damaged if assembled with hard faced pen presses, or clamps. Always use a firm, soft-faced pad over any pressing faces to prevent fracturing the finish near the edges of the barrels.
Safety Note: Always follow all manufacturers safety instructions before working with your lathe, or any of the tools or products you may use. If you are unsure about any operation, obtain competent professional instruction before proceeding. Use and wear all necessary safety devices during turning and observe safe woodturning practices to prevent accident or injury.
|Steven D. Russell is a professional studio woodturner, teacher and writer. He has written numerous articles for international woodturning magazines, which have been published in more than 78 countries around the world. Steve has demonstrated in numerous cities across the United States. His studio, Eurowood Werks, specializes in bowls, platters and hollow forms with unique visual and tactile treatments. |
Steve is also a regular featured writer for the Guild of Master Craftsman's "Woodturning" magazine, published in London England. Woodturning magazine is the world's leading magazine for woodturners. Look for his monthly articles covering technical topics, or project based articles in each issue.
Return from Plexitone Pen Finish Application Protocol to Main Library