Spray Paint System

E350 · 11-01-2015, 11:23 AM

Guys and Gals, I am putting together my little spray painting system. Please make recommendations for additions, deletions and changes. I have also posted it over at the snowblowersforum.com and the pwctoday.com forums. So if there are suggestions worthy of cross-fertilization, I will re-post them here.

Ridgid Air Compressor (which I alread own, primarily used for nail gun)

6.2 SCFM @ 90 PSI
4.5 Gal.
150 Max PSI

H.F. Oil Water Separator - maybe permanently mounted to my compressor
http://www.harborfreight.com/oilwater-s ... 68246.html

Desiccant Dryer/Filter - permanently mounted to portable air tank (below)
http://www.harborfreight.com/38-desicca ... 69923.html

Motor Guard D-12-1 Disposable Spray Gun Filter - to be attached to the gun just below the air regulator.
http://www.amazon.com/gp/product/B003TQ ... PDKIKX0DER

E350 · 11-01-2015, 01:31 PM

4 oz. HVLP Touch Up Air Spray Gun
http://www.harborfreight.com/hvlp-detai ... 46719.html

It has also been suggested that I use a Portable Air Tank to increase air volume for my little compressor:

http://www.harborfreight.com/7-gallon-a ... 94801.html

Finally, I am thinking of adding the manifold for the Oil/Water separator and the Dessicant Dryer/Filter permanently onto the portable tank, so I can disconnect it and move my air compressor around when using the compressor for other jobs, like the nail gun, etc., without fear of breaking the paint specific equipment.

What do you think?

witoke · 11-01-2015, 02:51 PM

That's almost exactly the set-up I had, HF filters, separator and gun, though with a bigger paint reservoir on the gun.

I am no expert but it worked well for what I was needing it for at the time and as I remember was pretty inexpensive. I started out with a HP gun and it took a while to realize that the higher pressure meant more paint waste.I did mount all the filters to the tank and just used a short additional hose to connect tank output to filters. It seemed simpler with the filters permanently attached. It worked well for the spraying I did. My compressor is an old sears unit, maybe 10 gallons and never had any problems with pressure loss but maybe HVLP is different?

On the advice of the place I was getting my paint, I filtered the paint through a paper cone filter as well. And of course don't spray indoors, use a respirator rated for VOC, (no facial hair allowed for a proper seal) and make sure it fits well. If you're only doing a few small jobs it's probably not as critical but several of the the solvents in paint and some of the thinners used for spraying are outright banned in Europe and are even under pressure here. I think MEK just became harder to get or maybe was banned? I remember reading something about it anyway.

I was spraying some larger surfaces and ended up wishing I had started with a large pressurized paint reservoir, to save time cleaning guns and pots and mixing paint but from the looks of the gun you are doing smaller things.

Hope my limited experience helps. Read up on spraying techniques too if you haven't already and try a few 'coupons' first to practice. FWIW, I found that trying to do too much coverage per coat was the biggest error I made. I found multiple thinner coats was better even if they looked like way too little at first. Pro's know how much they can lay on without problems but I think it takes time to figure that out for different paints, solvent proportions etc. A reasonable job is not too hard to get with patience and care but I found that a really good job takes a lot more time and experience.

E350 · 11-01-2015, 03:31 PM

witoke: Thank you for your thoughts. What spray painting system/equipment are you using now?

boywonder · 11-01-2015, 04:31 PM

Looks fine....a couple of comments......

I used those orange disposable filters when I painted my top and they worked fine...right at the gun.

The filter/dryer won't work mounted right at the tank air outlet....the air coming out is too hot so the water is still in vapor phase. For these to work properly you want them at the end of a long hose so the air has time to cool and the water is liquid.

E350 · 11-01-2015, 04:37 PM

boywonder: Excellent comments! So should I put my portable air tank closer to the work and farther away from the compressor?

witoke · 11-01-2015, 05:58 PM

Quote:

Originally Posted by E350

witoke: Thank you for your thoughts. What spray painting system/equipment are you using now?

I haven't had the need for any spraying for a while though still have all the same equipment. If I do get set up again I will get an HVLP gun and either a 1 quart gravity tank, (like your smaller one) or a larger pressure tank with just the gun on a short hose. I found the siphon tanks could be a problem if I needed to move the gun around at an angle to get into odd places.

I had my water separator and filters mounted to the side of the compressor and while what Boywonder said makes sense, I never had any issues with my spray finish. Mind you, I live in the desert so the humidity is pretty low, especially when it's warm enough to spray outside.

The other thing I forgot to mention is that cleanup is important. If you clean it and blow it all out right away it's much easier than having to soak parts in acetone and dig around to get all the paint out. You don't have to ask me how I know that.

I don't think you could soak that plastic paint tank in acetone anyway, it would dissolve. One time I got epoxy on a swiss army knife and without thinking dumped it in the acetone vat to soak off overnight. In the morning I had a nicely red-tinted pot of acetone and a handle-less knife.

boywonder · 11-01-2015, 06:45 PM

Quote:

Originally Posted by E350

boywonder: Excellent comments! So should I put my portable air tank closer to the work and farther away from the compressor?

Sure, couldn't hurt........put the dryer on the portable tank.

boywonder · 11-01-2015, 06:48 PM

Quote:

Originally Posted by witoke

The other thing I forgot to mention is that cleanup is important. If you clean it and blow it all out right away it's much easier than having to soak parts in acetone and dig around to get all the paint out. You don't have to ask me how I know that.

......what he said ^^^^^.....I run reducer through the gun a few times changing the reducer out between rinses until it blows clear. I usually blow the gun into the trashcan to capture most of the reducer.

This is really important when using 2 part/catalyst paint.....you may as well toss the gun if it hardens in the gun.

JWA · 11-02-2015, 04:53 AM

If you're new to spraying automotive finishes some find the Motor Guard disposable filters a bit cumbersome and take a bit of getting used to when they're incorporated. When air/material is first called for there's a bit of a lag as the housing fills with air, a noticeable drop in air/material flow until equalized.

If like most painters you'll "cycle" the gun trigger at the end of each pass this lag is very noticeable, could have an impact on the spray pattern and material as its laid on the panel.

There should be quite a few YouTube videos how to get the best results----like so many things its a learned art and technology all rolled into one action.

Also keep in mind spraying takes a LOT of air volume under constant pressure and flow---no such thing as a compressor that's too big volume wise. Match your system carefully to the real world needs.

FWIW I once owned a body shop, long before HVLP came into being----that's a wonderful approach these days!