# Spray Gun Cleaning



## Tony B (Jul 30, 2008)

I just noticed on Harbor Freight's website a gun cleaner for $99. It supposed to clean the gun in about a minute. I shoot mostly nitro lacquer and pre-cat lacquer and usually clen up with lacquer thinner. The instruction manual for the gun cleaner states to *not* use anything flamable. I can read the internet and get lost in different products, but what I want is someone here with actual experience with a gun cleaning machine and non-flamable cleaner. 
Thanks in advance.


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## cabinetman (Jul 5, 2007)

I don't have that machine, and I don't use non flammable solvents to clean spray guns.

Most of the non-flam solvents are basically degreasers. I haven't found one that will efficiently clean a gummed up spray gun from lacquer. An example of a non-flam solvent could be Citristrip...a waterbased stripper. That made to work in a tank IMO would take a lot longer than a minute even under pressure.

If you've ever cleaned a spray gun, and I'm betting you've done plenty, you know you can spray solvent through the gun until it runs clean. Then when you disassemble the gun and do all the parts you find all sorts of gunk not cleaned by running solvent through.

So, you have to excuse me for answering this thread as I have no experience with that particular machine. I just think it's a waste of money.


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## Rick Mosher (Feb 26, 2009)

Your post is a little confusing to me. Do you really mean that you want to use a solvent? I have a gun washer at the shop and use it every day. I pump MEK or acetone through it. Cabinetman, there are actually parts of the country where you are REQUIRED to use a gun washer and are not even allowed to wash your gun without one. (It was that way when I lived in So. California) The only way they work well is to flush the gun immediately after use. If I am using pigmented finishes I always just break the gun down and clean it by hand. A good unit will pump solvent through your fluid lines also which does come in handy occasionally. Here is a link: 

http://www.herkules.us/guncleaners.php


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## Rick Mosher (Feb 26, 2009)

In case you did mean non-flammable solvent, any machine that will use a flammable solvent will also use any non-flammable solvent.


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## cabinetman (Jul 5, 2007)

Rick Mosher said:


> Your post is a little confusing to me. Do you really mean that you want to use a solvent? I have a gun washer at the shop and use it every day. I pump MEK or acetone through it. Cabinetman, there are actually parts of the country where you are REQUIRED to use a gun washer and are not even allowed to wash your gun without one. (It was that way when I lived in So. California) The only way they work well is to flush the gun immediately after use. If I am using pigmented finishes I always just break the gun down and clean it by hand. A good unit will pump solvent through your fluid lines also which does come in handy occasionally. Here is a link:
> 
> http://www.herkules.us/guncleaners.php



So, are you saying that a gun cleaning machine will do a better job than by taking the gun apart and cleaning by hand?


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## Rick Mosher (Feb 26, 2009)

No, I didn't say that at all. But there are parts of the country where you are not allowed to take your gun apart and clean it, so what do you do then? For clear finishes it is much faster than taking the gun apart as long as you clean it right after use. Still the best way to clean a gun is to completely disassemble it and clean with proper sized cleaning brushes. (But that wasn't the question...)


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## jraksdhs (Oct 19, 2008)

*i find that VERY hard to believe...*



Rick Mosher said:


> No, I didn't say that at all. But there are parts of the country where you are not allowed to take your gun apart and clean it.



That makes no sense at all. How can a state tell you how to clean a spray gun. I can see them telling you that you cant fill the cup with laquer thinner and just spray away. But taking apart a gun and cleaning then with brushes and tiny needles is the ONLY way to get them truely clean. Professional shops use expensive gun cleaning machines but still take them apart periodically and clean them the right way.

jraks


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## Tony B (Jul 30, 2008)

I attached a link to the spray gun cleaner. C-Man, i clean my guns all of the time but cleaning them from pigmented lacquer is neither fun nor fast. Basically, all this cleaner does is clean the parts and runs solvent through the gun for you. Recently I have been working for 2 decorators that use pigmented lacquer on everything. I strip the antiques and paint (colored pre-cat lacquer) them various colors. Later on this coming week I will be spraying at least 15 pieces of furniture 6 different colors. I went to HF and bought 3 cheap guns ($20 each on sale) to suppliment my existing 3 guns. This way, I can spray almost continuously with one color per gun without having to clean the guns other than a quick shot of lac thinner through them. Then only have to clean the guns good only once a day. With the gun cleaner, I can have my helper or the LOML clean the guns for me. I spray something almost every day and this would be a good time saver. .......I think.
I shutter the thought of clear coating an expensive piece of furniture and having a short spit of color hit the surface. 

ALMOST FORGOT>>>>> Yes, I want to use lac thinner or acetone. The manual for the cleaning unit says only use non-flamable solvents. I was just thinking that they may say that just as a disclaimer in case of fire. 





http://www.harborfreight.com/manuals/94000-94999/94996.pdf


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## Rick Mosher (Feb 26, 2009)

The California reg was put in by the SCAQMD (South Coast Air Quality Management District) In their opinion VOC s from spray guns and spray finishing were one of the causes for smog in Southern CA and global warming in general so one of the regulations was that you could not clean your guns in an open container of solvent and commercial shops were required to purchase a gun washer and use it. Almost all painting and finishing done in CA is done using water based coatings these days. But don't worry, it's coming to your town soon.


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## Rick Mosher (Feb 26, 2009)

By the way, an SCAQMD air pollution control officer has more authority than a highway patrolman in CA. They can come into and search your shop without a warrant and arrest you also.

"RULE 105. AUTHORITY TO ARREST
The Air Pollution Control Officer and every officer and employee of the South Coast Air
Quality Management District designated by him is authorized, during reasonable hours,
to arrest a person without a warrant, whenever he has a reasonable cause to believe a
person has committed a misdemeanor in his presence which is a violation of the Health
and Safety Code or any provision of the Vehicle Code relating to the emission or control
of air contaminants or any order, regulation, or rule adopted thereto. Authority to arrest
is granted in accordance with Penal Code Section 836.5."

If you would like to read any more of the fun here is a link:

http://www.aqmd.gov/rules/rulesreg.html


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## cabinetman (Jul 5, 2007)

Rick Mosher said:


> The California reg was put in by the SCAQMD (South Coast Air Quality Management District) In their opinion VOC s from spray guns and spray finishing were one of the causes for smog in Southern CA and global warming in general so one of the regulations was that you could not clean your guns in an open container of solvent and commercial shops were required to purchase a gun washer and use it. Almost all painting and finishing done in CA is done using water based coatings these days. But don't worry, it's coming to your town soon.



I was going to comment that the requirement would likely apply to commercial applications. I would think a hobbyist cleaning his gun in his garage or his backyard could possibly get away without buying a gun cleaning machine that may get used a few times a year. Of course there's always the big brother satellite photo close-ups and nosey neighbors to worry about. 

I switched to waterbased finishes years ago because of health reasons.


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## Rick Mosher (Feb 26, 2009)

Are you buying gravity cups Tony? If so maybe the Devilbiss DeKups system would work for you. It is a rigid plastic cup that has a disposable plastic liner that allows you to spray upside down using a gravity cup with no leaks. You could do several colors in different liners and only have to clean the fluid passage between the cup and nozzle.
Are these distessed paint finishes? If so, you can use latex paint and then spray your lacquer sealer and topcoat over it. The picture was done using thinned latex paint sanded through, sealed, glazed and then topcoated with pre-cat lacquer.

http://www.tcpglobal.com/spraygundepot/dekups.aspx


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## Tony B (Jul 30, 2008)

http://www.tcpglobal.com/spraygundepot/dekups.aspx[/quote]

Too late, I didn't even think of the disposable liners. I bought suction feed guns. So where were you when I was in HF? HUH? You could have called and reminded me. :yes:
I do have one gravity feed gun I never used, I will see if I can pick up some liners tomorrow at an automobile paint store nearby. 
These are not distressed finishes, just colors. I had already discussed that with the decorator. The only thing she wants distressed is a screen door to the pantry - go figya. I made some sample panels for her of some crackle finishes some glazed, some not. Also some sandblasted. She will make up her mind this week, I hope. Fortunately, money is not an issue. 

BTW, do you think the gun cleaner is safe to use with Lac thinner or acetone ( look back to Reply #8) ?


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## Rick Mosher (Feb 26, 2009)

I doubt it. If the solvent has to be pumped through any hose it probably isn't rated for use with solvent. I can't really say without looking inside. You may be able to change out the lines but my guess is being HF it would probably work out to be a waste of money. There are a lot of cabinet shops going out of business right now, you may be able to pick up one cheap online. Good luck with your job. That is why automotive shops use the 3M PPS or Devilbiss DeKups systems, it is so easy to go from one color to another. 

I have a 12' Parsons table that I have to spray high gloss white next week. I'll spray the Evercoat Slick Sand polyester primer and the white 2k urethane with a Sata gravity cup and then clear coat with the Kremlin 1014 using Milesi clear gloss 2k urethane.


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## Tony B (Jul 30, 2008)

Rick Mosher said:


> ........I have a 12' Parsons table that I have to spray high gloss white next week. I'll spray the Evercoat Slick Sand polyester primer and the white 2k urethane with a Sata gravity cup and then clear coat with the Kremlin 1014 using Milesi clear gloss 2k urethane.


Funny you should bring this up. I was about to re-visit my earlier post on mirror finishes. I was going to ask what polyester product you used and with which urethane for a deep mirror finish. And.............do I need any special set-up to spray that stuff. Man, those mirror finishes are addicting. Lots of work but definitely an addiction. I have done 4 so far using just a pre-cat lacquer and guessing that I am not exceeding 5 mils DFT. I really need to get hold of an eddy current DFT gage.


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## Rick Mosher (Feb 26, 2009)

Actually you need a wet film thickness gauge. You measure the WFT and then calculate the DFT. You can calculate the DFT by using the solids content (by volume) of the finish and how thick you spray each coat (wet mils). For example, if the finish has 30% solids by volume and you spray a 5 mil coat, then only 30% of those 5 mils will be left once the solvents evaporate (the other 70% of the finish). Multiply 30% (0.3) by 5 and you get 1.5. So spraying a five mil wet coat leaves you with a 1.5 mil dry film.
Your coating mfg. should be able to supply you a wet film thickness gauge, usually free. If not you can buy them online, here is a link to a cheap one:

http://testcoat-usa.com/Product/WetFilmGaugePlastic.aspx?adsource=froogle


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## Tony B (Jul 30, 2008)

I have wet film gauges but they wont do any good with all of the sanding involved while still building layers to flatten the surface before buffing. 
When I build my layers, I start with a vinyl primer and a light sanding. Then I apply my next coat very wet or what I call wet on wet which is actually like 2 coats - 1 coat followed by another very wet coat an hour later, but I let it dry overnight. When dry, I dry sand with 320 on a ROS making 2 passes and then 1 additional pass with a hand pad sander along the grain. Then repeat the whole process until surface is very flat - no shiney spots. This will usually take about 5 coats total. So, with all this sanding, this is where I lose the ability to know how much is really left behind. Once flat, I start with 320 wet sanding on a 1/4 sheet sander. Then jump to 400, 600 and 1200 grit. Then from there I use a 3 stage buffing schedule.

I guess I could make a sample using my typical mirror finish technique, starting by using a micrometer to measure the thickness of the bare wood and then after finishing, slice it up into random pieces and mic it again. Damn, I dont have that kind of ambition. LOL


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## Rick Mosher (Feb 26, 2009)

I don't recall what brand of pre-cat lacquer you are using Tony but if it is ML Campbell then you could try their Level post-cat high-build sealer. It doesn't add to the DFT and builds almost as good as polyester.


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## Tony B (Jul 30, 2008)

I am currently using WFS Coatings pre-cat and their vinyl sealer. Also use Sherwin Williams products and both recommend a 5 mil DFT maximum including sealer.
I will definitely check out ML Campbell. 
Thanks


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## GeorgeC (Jul 30, 2008)

jraksdhs said:


> That makes no sense at all. How can a state tell you how to clean a spray gun. I can see them telling you that you cant fill the cup with laquer thinner and just spray away. But taking apart a gun and cleaning then with brushes and tiny needles is the ONLY way to get them truely clean. Professional shops use expensive gun cleaning machines but still take them apart periodically and clean them the right way.
> 
> jraks


That is exactly my thought. It makes absolutely no sense that some state would tell you that you cannot dissamble a spray gun.

I would have to read that law myself.

George


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## Tony B (Jul 30, 2008)

*Morning Coffee*

I am still working on my first pot of coffee and almost have the cobwebs cleared from my brain. I appreciate all of the help. This mornings assignment for me is two-fold. 1) Call HF tech support and find out exactly why I cant spray a flamable substance through it. It may be as simple as a fire hazard liability. 2) Call ML Campbell tech support and find out exactly what the meaning of "Color: 0-2GH Hazy" means to me in reference to their Level Sealer and what is the recommended top coat. 
Also sched for 11AM this morning is a salesman and the store manager for Sherwin Williams will be coming to my shop for a meeting. They want to introduce themselves and sell me what they can. Life can be interesting.
Rick, thanks for steering me in the right direction and I will keep you informed of the outcome.


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## cabinetman (Jul 5, 2007)

As long as you have the SW guys coming over, ask them about conversion varnish.


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## cabinetman (Jul 5, 2007)

Rick Mosher said:


> I have a 12' Parsons table that I have to spray high gloss white next week. I'll spray the Evercoat Slick Sand polyester primer and the white 2k urethane with a Sata gravity cup and then clear coat with the Kremlin 1014 using Milesi clear gloss 2k urethane.



Have you tried DuPont Imron? Works pretty good for solid colors. Or, maybe a polyester lacquer. Both don't need much build for a fine high gloss finish.


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## Tony B (Jul 30, 2008)

1) Called HF tech support and found out exactly why I cant spray a flamable substance through it.* Because the pump is not rated for chemical solvents like lacquer thinner or acetone. This is mainly for use with waterborne chemicals. Gee, HF never said so on the labels. I noticed that by reading the manual. This ain't the first time HF did that.*
2) Call ML Campbell tech support and find out exactly what the meaning of "Color: 0-2GH Hazy" means to me in reference to their Level Sealer and what is the recommended top coat.* The color referred to is the actual color of the chemical in the can. When mised it becomes clear. Mystery solved. The recommended top coat for this product is any form of lacquer whether nitro , pre -cat or post cat. For table tops, post catalyzed will be best. *
11AM this morning a salesman and the store manager for Sherwin Williams came to my shop for a meeting. *They introduced themselves and we talked finishes. SW can get me most of the chemicals I am using now and they are closer than my other supplier ( 5 minutes vs. 45 minutes) and they both deliver. *
*SW can even get me crackle lacquer when I showed them some sample panels I made. It turns out that SW owns ML Campbell - live and loin.*
*They also brought me some PDS's for polyester finishes. We also discussed the euro finishes. I really impressed with European finishes although very expensive they could still be cost efective. I was also depressed about American finishes being so far behind in technology. You can buy 2 component polyurethanes that are super hard, resist most chemicals and will lay down to a mirror finish with no sanding or buffing - made in Italy. *

*Cabinetman writes: *As long as you have the SW guys coming over, ask them about conversion varnish.
*Conversion Varnish is an excellent product, far superior to post catalyzed lacquer. The max. allowable build is pretty much the same as lacquer - 5 mils total system. *

I think my immediate future plans will be to continue with lacquer on restoration projects using post cat. on the tops and nitro on the rest of the piece. 
For mirror finishes I will start with the ML Campbell Level Sealer and post cat. for the final coat.
On new furniture I build I will probably go with a conversion varnish the whole trip. At least that is my current plan. I still have to use up a drum or so of pre-cat.


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