Do I need a dryer on my compressor to use HVLP?

[Joe Jensen]

I posted a few days ago about the deal I got on a Quincy compressor. The main reason for my upgrade was to get a largre machine to drive my HVLP gun.

I live in Arizona and it's generally very dry here. I'd like to do it right with the compressor setup so I was planning to buy a desiccant dryer. Yesterday the dew point was 25 degrees. A plus with the refrigerated unit is that the air comes out cooler, but I've also read that better units reheat the air to prevent condensation later. The cost for an appropriately sized refrigerated unit is between $400 and $800 depending on if I can find a good used unit. The other option is a desiccant dryer. Cost here looks like around $150.

I'm pretty tight on space, and a refrigerated unit takes up room in the shop. If cost was not a factor, would you get a refrigeraterd unit given I live in AZ? If I get one, what do I need to look for? The ratings are different between units for incoming air temp, and ambient air temp. Also, it seems like a wood shop isn't necessarily the best place for a refrigerated unit given all the dust. Any concerns here?

I would be using this pretrty infrequently, maybe once a month.

thanks...joe

I'd love some inputs from those with experience.

[Joe Chritz]

You need something to take out the water. What ever does that is great.

I use an fairly inexpensive water seperator I picked up at an automotive store the sells auto paint.

Couple that with a few drops in the pipe and regular tank drainings and I have yet (insert wood knock here) to have a problem with water issues.

Joe

[Jim Andrew]

I used to spray lacquer in houses I built. Just drained the compressor every day. Seldom had a problem with water. Although it can happen. A trap built out of pipe in your line, with a plug for a drain in the bottom can work as a water trap, but nothing is probably going to be perfect. When spraying, had better luck with just a conventional cup gun than hvlp, seems that the material comes out in bigger drops, but the fog of lacquer was much less with the hvlp.

[Joe Jensen]

Thanks Joe. I have Wilkerson particulate, and coalescing filters. I think the coalescing filter separates water and oil. I've used a Devilbiss pressure feed conventional type setup for years without any issues as far as I've seen with respect to moisture, but the HVLP will consume a lot more air, and this new compressor is a 175 PSI unit which I've read will cause more condensation than my old single stage...joe

[David DeCristoforo]

You only have two choices. A water trap which will remove "most" of the condensation and should be fine in a dry area like yours or a "refrigerated after dryer" which will probably cost more than the compressor.

[Joe Jensen]

Here are a couple of options for refrigerated units. The first one is a no-name from E$ay

The first one is $285

BRAND NEW ADVANCED 3-IN-1 REFRIGERATED AIR DRYER!

Keep Air Lines Bone-Dry Advanced 3-in-1 air dryer system features modes for pre-refrigeration, evaporation, air and moisture separation modes to remove up to 90% of the moisture from your compressed air lines. Lowers the dew point to 36°F. Operates between 35.6°-140°F. Uses R-134A refrigerant.

High efficiency prerefrigeration system is three times faster, takes 60% less power to operate
Accommodates compressors up to 21.6 CFM, 140 PSI max.
Recommended operating pressure: 100 PSI
115 V input
Air inlet: 1/2"-14 NPT
Weight: 73 lbs.The second one is $680 from Grainger, closeout model marked down from $1680. This one is clearly larger, rated for 25CFM.

[Larry Fox]

Best advise I can offer is to give Jeff Jewitt at Homestead Finishing a ring. He is a really nice guy and knows his stuff.

[William OConnell]

no Just an inline water seperator

[Matt Meiser]

Harbor Freight sells a dryer too that looks like that maxhootue one. I've seen designs for homemade dryers which were basically spiral of copper tubing in a trashcan filled with cold water. Another design I saw was an intercooler that goes between the pump and the tank. Again basically a spiral of copper tubing, but air-cooled. The owner of that one claims it works extremely well.

I don't find I have much moisture issues, but spraying WB products I don't think I'd notice. In my system there's probably 30+' of piping between the compressor and where I plug in the hose for my gun which I think helps a lot. The main trunk is sloped away from the compressor with a drip leg at the end and my drops have drip legs as well.

[Joe Jensen]

It's really funny now that I think about this more. I used solvent based product for years without, and now that I'm moving to water based it really shouldn't matter that much.

I'll call Jeff, I bought my HVLP gun from him....joe