Shellac Finish Gun and Brush Clean-Up

Tips on cleaning up equipment after applying shellac. November 27, 2007

I use Zinsers de-waxed shellac for both brushing and spraying purposes. When I am done, I rinse the brush with denatured alcohol to dissolve all of the shellac, but by morning, they are hard as a rock. I then just re-soak the brush and spin it out. What is a good cleaning method to keep the brush from stiffening?

I have also gone through about 3 siphon fed detail guns I use to apply stains and sealers, but it is getting to the point where I won't run de-waxed shellac through my gun because I can't clean it properly.

I am a new construction residential painter, so using HVLP is still pretty new to me. In the past I have always applied my clears and stains with an airless pump, but even at real low pressure with a fine tip, it's just too much. I have learned a lot from talking to auto body painters and wood finishers about the use of HVLP as well as just experimenting all the time, but it's the gun care and maintenance that is getting me. For now I use a 4hp 13 gallon air compressor to spray stains and sealers and it works beautifully. My only problem is that I think I need to start using some kind of oil and water dryer because I get small water droplets every so often that shoot out of the gun and onto the surface I am finishing. Not only that, for the first year I owned my compressor, I did not know that I had to drain the tank after every use. What a surprise when I finally did.

I'm only 20 years old and I want to gain as much knowledge as possible on everything that has to do with wood finishing because it is hard to find people nowadays in my field that actually know about the materials they are using.

Forum Responses
(Finishing Forum)
From contributor P:
On brushes, why bother cleaning them if all you use them for is shellac? I grew up in an old-timey shop and we never bothered cleaning shellac brushes. Just hang them and let them dry where they can't get all dusty. Big jars are great for this. Poke a hole in the top, stick the handle through it, and then stick a nail or something through the hole on the brush handle to suspend the brush. Next time you need that brush, soak it in denatured alcohol for a bit and wipe it off.

From contributor K:
I clean my gun with ammonia and water and then run alcohol through it. And I use a dedicated gun for shellac. You might also look into Target's water based shellac, as it is supposed to clean up easily.

From contributor P:
I use the Target shellac a lot and it does clean up easy. Plain water will clean up the gun if you spray half a cup through right after. I take the air cap off and soak it in water for a few minutes immediately after spraying and it cleans up with a soft nylon brush. If you let the stuff dry, it's a bit harder to get off.

From contributor G:
The mysteries of finishing can be daunting, but time spent browsing the Finishing Forum Knowledge Base will answer most of your questions, including "why does lacquer turn yellow?". You will also find the titles of the finishing bibles that are recommended reading. For now, why are you using all that shellac in the first place in new construction?

From contributor R:
First, before you use the brush, pre-wet with clean alcohol. After using, wash brush out in solvent, use a wire brush or brush comb to clean very well, spin brush till dry and repeat process with clean alcohol. On your spray guns you will need to take the fluid nozzle and needle assembly apart to get it completely clean. Buy some of those bottle cleaning type brushes - they sell them at automotive paint stores, and they work great in those tight places. Same as with the brush after the first cleaning and you have put the gun back together, spray new clean solvent through the gun.

From the original questioner:
I don't use shellac as a finish in new construction, but I do use de-waxed shellac sealers over top of oil based stains for brushing purposes.

From contributor T:
Brushing shellac requires good brushes dedicated to shellac. They need not be cleaned after each use. Rinse them in alcohol and let them dry as contributor P has recommended.

Another inexpensive cleaner for your guns is a strong solution of 20 Mule Team Borax. Follow with a flush of alcohol.

If you're interested in the whys and wherefores of finishing, you should have Flexner's book, "Understanding Wood Finishing."

Don't let anyone turn you off on shellac. Properly used, it's great stuff.

From contributor M:
Flexner's book is awesome!

From the original questioner:
20 Mule Team Borax - what exactly is it, how do you use it, and can you use it for other materials?

From contributor T:
It's a multi-purpose cleaner available in the laundry detergent section of most supermarkets. Mixed with water it produces a very alkaline solution that, like ammonia, dissolves shellac. Mix it strong and you can reuse it. Any strongly alkaline cleaner will dissolve shellac. You heard about the guy who cleaned his restaurant tables with ammonia and couldn't figure out why it took off the (shellac) finish?

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor D:
Use shellac if you wish, but after over forty years I still topcoat it with a thinned layer of varnish to protect the shellac. Varnish has a strong tendency to yellow but the shellac is applied in various shades of amber. The varnish does yellow slightly. Always use de-waxed shellac if you do topcoat with varnish.