Using Cyanoacrylate as a Finish

People often ask how I use CA. There are many "systems" described on the internet. It is a common finish for pens, for example. Unfortunately, it is a bit unpredictable and many people never get it right before they give up in frustration. It is affected by the ambient humidity and temperature, the wood type and wetness, the moon phase, and many undocumented minor factors. It goes on relatively easily for me about 80% of the time, and the other 20% of the time it is a real pain in the neck.

Wear safety glasses and thin rubber gloves -- it will save your eyes and fingers.

Here is how I apply it on the lathe:

1. Shape and sand the piece to 220 grit.

2. Wet sand (using 220) the piece w/ CA as the liquid. Use just enough CA to coat the wood and create a little bit of a slurry. This fills the grain and seals the wood. Keep sanding until the CA cures and then sand off the majority of the CA. If you leave CA on the surface it may create a discoloration blemish that is really just the CA w/ very fine dust in it causing a darker color. This doesn't always happen, but if you see a dark streak in your finish, you will know what happened. The goal is to fill the pores of the grain and seal the grain, not get a real finish here.

3. Sand the sealed piece through at least 320 grit. I usually stop here, but for very hard woods, I will go to 600 grit or use steel wool to get a dull sheen on the wood.

4. Fold up a 1/4 of a paper towel and apply a few ml of CA to the paper towel. Rub the CA on the wood fairly quickly. This is a lot like rubbing on any other finish except that the CA cures more quickly. W/ medium viscosity, the CA will start to cure in 15 - 30 seconds with this first coat, so don't dally.

5. Let the CA cure completely. I usually give it 10-15 minutes and work on other tasks in the mean time.

6. Inspect the first coat. If it is reasonably smooth (the grain shouldn't rise since you sealed the wood) just put a second coat on like the first. If you didn't get a smooth first coat, you may want to smooth it out a little w/ steel wool.

7. Continue to add coats until you have a smooth surface. Smooth w/ steel wool between coats if needed (I usually don't need to do this more than once). If you want a bright polish, you need to completely fill the grain. As the coats add up, the cure time gets longer. Up to an hour or more depending on conditions. I usually put 2-3 coats on and then let the finish cure for a few hours. Then come back and put 2-3 more coats on. That is usually enough to get a nice polish w/o making it too thick.

8. Once you have completed the last coat and it is cured, polish the piece with plastic polish or a Beall buffer if you have one. Finish up w/ a bit of wax. I use carnauba wax, but have used car wax too.

You don't have to apply the finish on the lathe, but it does help keep things even. If you don't apply the finish with on the lathe, you may need to sand (lightly) the finish between coats w/ 600 grit paper to keep the finish even.

That's it! Good luck. Be patient. It works, but like I said, it is a bit unpredictable.