Recommendations for setting up a spray system

[gnachman]

I'm getting started with spraying for the first time. I have a portable oil-free compressor and an HVLP gun. My plan is to spray shellac or lacquer on the occasional small project in my back yard. I thought I was all ready to go, but then I started reading the manual for my gun (always a bad idea!). It says: "achieving a fine spray finish without the use of a good oil and water extractor is virtually impossible" and goes on to recommend that I buy their $200 extractor (DeVilbiss HFRL-508).

- Do I really need such an expensive extractor? I'll buy it if I have to, but I'd rather find a more economical route if it the tradeoffs aren't too bad.

- I don't have permanent plumbing as depicted in the manual: only flexible hose. My compressor is on wheels and I want to work in my back yard. So how should I arrange for the separator to be 25 ft from the compressor with the pipe sloping down towards the separator? Can I coil up my 50ft hose, tie it to a tree, attach the extractor to that, and use a short length of hose from that to the gun? Seems crazy.

[Michael Pyron]

since you have an oil less compressor you shouldn't need the oil extractor, just a water extractor...

you should be able to get a Campbell-Hausfeld one from Hell Depot for less than $50 (sorry, I got mine a long time ago and forget what it cost and have no clue as to current prices)...

what I do is to use 25' of 3/8" hose to run from the compressor to the extractors (I have 2 as I do have an oil lubricated compressor)...I run that straight up to my garage ceiling, run it a bit, then drop down to my extractors which then ties to my pressure pot about 12' away then runs to my gun...or if I am using a cup I just run straight off of my extractor system...in the field I've run the hose from the compressor across a couple of ladders to hold the hose in the air and then dropped to my extractors which I tied to a board and supported with some screws set up as pegs and located them under the fittings...I'm sure you can figure out something similar to use in your back yard...

good clean air is definitely a must for spraying..

[Scott Holmes]

Another way is to get a DRIER you can usually buy a canister type Drier with desiccant granuals in it for $8 or so at "Tractor supply" or maybe even a "big box store". Attach it to your gun and you are good to go...

I think I've seen them at Northern tool too.

[Henry Ambrose]

If its hot and dry where you live you might want to try it just as it is now. Spray a board and see what happens.

[Phil Phelps]

Another way is to get a DRIER you can usually buy a canister type Drier with desiccant granuals in it for $8 or so at "Tractor supply" or maybe even a "big box store". Attach it to your gun and you are good to go...

I think I've seen them at Northern tool too.

You're killin' the fun of spending a couple of C notes

[Jeff Jewitt]

1. The most economical way to go for you is an in-line water separator/extractor which will pull off the large amount of water droplets that occur in hot/humid conditions and that hose length. Most of these designs have manual purge valves when you see that the barrel is full of water. They install right at the base of the gun.

2. The dessicant water vapor in-lines are usually silica granuals that turn color when they are saturated, but these should be avoided unless you have some sort of water extractor upstream. Otherwise on a humid day spray session they'll be saturated almost immediately with water droplets.

3. A disposible, all purpose filter that has paper media inside is a good choice if you don't spray much, These filter oil, particulate and water but have to be monitored as they'll last only 8-10 times in humid spray conditions. In the trade these are referred to a "toilet-paper" filters because the media inside looks like a minature roll of TP. Devilbiss calls their's "whirlwind" filters.

[Bill Davis]

One of the biggest impediments to 'perfect' spray finishes is moisture. Even if you live in a dry climate moisture is a problem because of the physics of compressing and releasing compressed air. There is a lot of good info out there on all of that. Remember this though: Most all sources of info give good professional advice to professionals who cannot afford too many disasters requiring rework. They will give the most conservative recommendations - conservative in all areas of spray finishing except for your pocket book. Guess why? To ensure your success and their pocket book.

All that being said here's my personal experience. I started much as you are beginning, a simple portable compressor (except mine was not oilless), a good non-HVLP gun (which I am still using) and the wide open out doors as a spray booth. I spray mostly lacquer but have done others such as poly, water based, latex paint and more. I now live in a very humid location which makes spraying lacquer difficult, but not enough to prevent getting excellent results. See one of my projects built from Narra and with 5 coats of gloss lacquer hand sanded to a semigloss final appearance here. I don't use, nor have ever used, a dryer in my air line! I can only dream of how nice it may be when I decide to spend my $ on one rather than on other things of my choosing. I use simple inexpensive Campbell Hausfield and Harbor Freight filter/regulators. I started with virtually nothing and have only added a bigger compressor and some permanent piping. Nothing exotic.

My advice is to read and try to understand all of the details you can then try spraying with what you have. Learn to recognize the cause of problems that occur and solve that problem the easiest and least expensive way possible. You'll learn more that way and won't break the bank and you will turn out some beautifully finished projects. Unless you're doing it comercially/professionally you don't need all the hi-tech, perfection guaranteeing, gadgets. IMHO! I like lacquer partly because of it's beauty, ease of spraying and easy repair/rework. Spray and have fun! It can be done. One day I'd like to try HVLP.

[Scott Holmes]

Jeff,

Thank you you make a good point on the in-line water separator/extractor. I have oil/water separators inline and verticle drops so the little cheap inline driers at the gun work for my setup.