Need advice on spray system with 27 gallon 7.2@40 psi compressor

[Duncan Foster]

Have a decent craftsman compressor but probably not strong enough for HVLP. Building some small projects shelves etc. and would like to spray waterbourne latex. I don’t mind spending a couple of bucks but would rather not get a system i.e. or Earlex 5500 if I have what appears to be an OK compressor. Have gone down the Rockler road with their all in one unit and hated it. Bought a cheap gun at Home Depot that didn’t seem to help either. Any suggestions would be appreciated.

To be specific I am building a firewood storage unit for a covered patio. Just looking for a good quality smooth finish and the ability to paint future projects without getting involved in solvent-based finishes. I looked at Homestead finishing website but got even more confused.

Feel free to recommend any primer/paint combination that you think a newbie to finishing could use with success.

[John TenEyck]

You should be able to use several HVLP conversion guns with your compressor. If you want to spend darned little get something like this TCP/Global gun with a 2.0 mm N/N:

https://www.amazon.com/TCP-Global-Pr...-2-spons&psc=1

They offer the same gun with a 2.5 mm N/N, too if you want to spray even higher viscosity stuff, and that likely will be the better option for exterior WB paints. At $45 you're not risking much.

If you want to spend more, you could get the Qaulspray AM-6008 SmartPak from Homestead Finishing. That one gun will spray everything from WB dyes to BM Advance w/o thinning. I've had one for several years now and am very satisfied. If you go that route I strongly recommend you get the 3M PPS cup system with it. Clean up is much easier, you can see how much finish is still in the cup, and you can spray at any angle. That package costs about $375, so it's quite a step up. It won't spray much better than the cheap gun, it's just a lot more versatile.

For an outdoor project you need exterior grade products. Most WB exterior paints are going to be too thick to spray through a gravity feed gun w/o thinning. I've sprayed ProClassic (500 sec. #4 Ford Cup) with a 1.8 mm N/N after thinning it 18%. Not something I would recommend, but you should be able to spray those type of products with much less thinning through a 2.0 and definitely a 2.5 mm N/N.

For indoor projects you have more finish options, but don't use typical latex paint products. They aren't hard enough for cabinets/furniture. Appropriate products include TC's EM-6500, which can be tinted to any color you want, as can Duralac or MegaVar by BM. Those products are in the 100 sec. viscosity range and should spray very well through a 2.0 mm N/N in a gravity cup gun with little/no thinning.

John

[Duncan Foster]

Awesome information. Thanks for sharing. I’ll start cheap then move to homestead products if necessary. Thanks again

[John TenEyck]

Awesome information. Thanks for sharing. I’ll start cheap then move to homestead products if necessary. Thanks again

Happy to help. Spraying is a confusing subject; mostly because it's hard to find information about what to buy to spray X, Y, Z products. I had the same dilemma when I started spraying about 10 years ago. So I started cheap and found out cheap works just fine for most things.

I assume your compressor has a cheap filter/regulator on it. That should be fine; that's all there is on mine. I set it at 90 psi. I drain the water out of it and out of the bottom of the tank daily, more if I'm spraying all day. I have a 3/8" hose from that regulator to my spray area, 50 ft away. For the regulator that comes with the gun I linked to, I typically set that at 29 psi. I also have a cheap in-line filter just before the mini-regulator to catch anything coming from the compressor. They are like $4 at HF and last a long, long time.
you shouldn't need more than this as long as you don't live somewhere with extraordinarily high RH.

If you don't have a cheap #4 Ford viscosity cup, buy one. They are like $6. Measure the viscosity of what you want to spray and use it to adjust the viscosity until it's in the range for your gun. Don't eyeball it; measure it. Keep a log of viscosity and gun settings so you can repeat things in the future. Look at Jeff Jewitt's webpage on spraying paint for more guidance.

Practice on scrap until you are satisfied.

John

[Duncan Foster]

Really Great information. Hopefully anybody new to this will find this thread. I do live in a high humidity area but very fortunate to have a mini split air condition shop so hopefully humidity will not be an issue. Thanks again