HVLP gun cleanup - shellac

[Erik Christensen]

I have had my HVLP gun & 3 stage turbine for 15 years and sprayed tons of waterborne finishes but have stayed away from solvent finishes for a number of reasons - safety, fumes, and most important to me - cleanup. I now want to put a coat of shellac over a water based dye so I can try glazing. It seems the best way to do that would be to spray - but I am paranoid about the whole cleanup thing. I'd hate to goof up my trusty commercial Titan gun with a finish I don't know how to cleanup from.

What is your experience on being able to clean a gun after shellac such that you can go back to waterborne? I always run a full cup of water through the gun immediately after I finish my spraying project, then completely dis-assemble the gun and wash all parts esp the needle & tip with more water - So I was planning on doing the same thing after shellac except the solvent would be denatured alcohol.

Will this really work or should I get a HF cheapie HVLP conversion gun just to shoot shellac?

[Tony Bilello]

Many people spray lacquer through their guns and never have a problem. Lacquer is a lot tougher product than shellac.
I dont know what the proper clean-up solvent is for shellac, but I'm sure someone here does. Most gun clean-ups are fairly simple, just like you do with waterborne chemicals. I spray colored lacquer through my guns all of the time. In less than ten minutes, I can clean them to where I can spray clear lacquer over a bare wood surface and not have any unwanted residue shooting out.
The gun designers use materials in their gun manufacture that are easy to clean. This would be a necessary design requirement.

[Steve Kohn]

A 50/50 mixture of water and ammonia is also a cleaning solvent for shellac. I believe the ammonia is much safer to use that spraying alcohol to clean a gun.

[glenn bradley]

I just cleaned up some brushes; dipped in a little DNA and finished up with ammonia. Remember that when spraying shellac you are shooting atomized alcohol. Good air draw towards the filters and no sparks please.

[Joe Chritz]

I only top cup guns and it takes about 3 ounces of DNA to clean after a seal coat.

A siphon gun a tad more but it is really easy. You will likely have to do some wiping with paper towels or rags instead of running a ton of solvent through but it should only take about 2 minutes tops.

I now spray sealcoat with my spare gun and use the main one for waterborne topcoats generally but it really isn't necessary.

Joe

[Jim Becker]

I spray about a quarter cup of DNA through the gun to clear out residual shellac and then disassemble and manually clean with DNA and a towel. Occasionally, I'll go outside and do some better cleaning with some lacquer thinner that I keep specifically for that purpose. (I don't spray solvent-based lacquer in my shop) I have zero issues switching back and forth between de-waxed shellac and Target Coatings water borne finishes, even same day with proper cleaning.

[Scott Holmes]

Shellac with dye is a toner not a glaze. A glaze is more like gel stain, and it can hide the grain. Toners don't hide the grain.

[Phil Phelps]

I'm just the opposite. If I spray a waterborne product, I finish up with alcohol to dry the water in the gun. You guys with conversion HVLP's can add your cleaning solvent in the cup, turn the pressure up, lock it on and hit the trigger to spray. Then disconnect the hose and spray a stream instead of an atomized spray. And, those with the Croix and Croix knock off can dial the pattern to "0" for a larger stream. It's a great way to clean the gun with out spraying.

[Conrad Fiore]

Erik,
I use DNA and ammonia. I spray a small amount of DNA through the gun first and then follow up with a spray through of ammonia.

Scott,
I believe that Erik wants to use the shellac as a sealer so he can put a glaze over the top, not use the shellac as the glaze.

[Larry Fox]

I have a pressure-pot conversion setup and just blow DNA through it and, like Jim, have had 0 issues switching back and forth between shellac and Target Coatings WB products. I also use DNA at the end of the cleanup cycle for WB finishes.

I go through quite a lot of DNA (more than a quart per cleanup) because I have to clean out the lines and they hold a surprising amount of finish.

[Quinn McCarthy]

I bought a 5 gallon pail of gun cleaner from the auto parts store in town. Works great. Sometimes takes a couple days to get the thick stuff loose.

Hope that helps.

There are people that recycle the cleaner by letting it sit and skimming off the top. I have never done that however.

Quinn

[Jimmy Williams]

A 50/50 mixture of water and ammonia is also a cleaning solvent for shellac. I believe the ammonia is much safer to use that spraying alcohol to clean a gun.

I just finished spraying a coat of shellac on a desk project I am working on and I just cleaned the cup and gun with this same 50/50 mixture.

I was then able to use the same gun to spray three coats of Waterlox Satin. I only have a cheap HF gun and a 5 gal. compressor but the Waterlox came out great.

[Phil Phelps]

I bought a 5 gallon pail of gun cleaner from the auto parts store in town. Works great. Sometimes takes a couple days to get the thick stuff loose.


Quinn

I hope you're talking about the cup and not the gun.

[Faust M. Ruggiero]

Not that you asked, but, if you spray water borne lacquer with your gun, I will assume it is set up with 1.4 MM to 1.7 MM tip and nozzle. That combo might be a bit bog for shellac. Why not brush it. Can't you spray lacquer to seal the glaze from the bare wood. I like shellac but avoid using it under lacquer. I feel it becomes a weak link in that type finish.
fmr