Onboard Compressor for Painting, Diving, and Pneumatic Tools . . .

[ActiveCaptain]

I'm looking for product suggestions for a small onboard compressor. I'm way outside my experience area and know very little about them although I've looked around and have researched some of the issues. What I need now is personal experiences and particular product suggestions to research some more.

The three things I'd like to be able to do in order of need are:

1. Spray paint gelcoat. I touch up my own boat and have traditionally used the Preval sprayers. They don't do the best job and I'm looking for a better quality sprayer even if it means cleaning it.

2. Near-boat diving. I carry 2 tanks onboard but I'd much prefer a hookah setup when diving on the boat itself to check the bottom, running gear, etc. I'd never go more than 6' below the surface. Any more than that and I'd want the full tank, BCD, etc.

3. Air tools. There are times when having an AC extension cord through to the dinghy for using tools on the outside of the boat is just dangerous. There are some really nice air tools for mechanical work too.


I'm only interested in an AC compressor - not a gas engine or any other type of engine. I know that the diving requirement requires an oil-less compressor for obvious reasons. I'm also not looking for something very large - I'd like the smallest one that will meet these needs.

Any ideas?

[boasun]

You can go to "Lowes", "Home Depot", or any other hardware store or Auto parts store and peruse the compressers that they have on sale there. Thus you can compare the assorted sizes and what is needed for air tools. Just go a tad larger then is required by the most air hungry tool you are planning on using.

[djmarchand]

Jeff:

Your biggest air load will probably be for diving. Some years ago I bought a 2.0 SCFM Husky air compressor with an integral tank from Home Depot. It uses a non lubricated compressor. It works fine for diving, spray painting and air tools (within reason). I think I paid $100 for it.

You do know that a scuba regulator will not work with a Hookah rig. The supplied air pressure to the Hookah is much lower- about 30-40 lbs and needs a larger diaphragm and weaker spring to work properly. I bought mine from an Alaska gold mining supply house.

David

[ActiveCaptain]

Originally Posted by djmarchand

You do know that a scuba regulator will not work with a Hookah rig.

Yes, definitely - the live compressor is way lower pressure.

The "2.0 SCFM" is the type of specs I'm interested in. Is there a tank size that should be considered a minimum? I've seen tiny 2 gallon ones up to huge things that would never fit.

Also, is saying that it's a "a non lubricated compressor" or "oil-less" good enough to stick a tube on it for breathing? Do you use anything in front of the special regulator for filtering, etc?

Thanks - good info.

[doug86]

will run a small "airbrush" type paint gun for sure, because it was designed to run an airbrush. Might not keep up with a big air tool, but a small nail gun would work.

I breathed on one of these for years.
Model SS-E

[Mark Johnson]

You can make a small shallow dive "Hookah rig" out of an oiless compressor, but it will probably be barely adequate. I used one that I borrowed from a friend, and it was OK for a shallow dive, but not scraping the hull bottom, which had me panting! I would use an air filter.

For air tools and spray paint equipment, (other than just touch up stuff), I have found that a 5 hp is required. This is pretty big to have on a boat, along with it's pressure tank, and would require it's on generator if it ran on AC.

The very small portable units for a single nail gun, would be just adequate for small touch up work. It would also use quite a bit of power.

Perhaps you should consider a Brownies Third Lung "gasoline model" hookah rig, which is fine for shallow dives, and could probably be retrofitted to operate small "touch up" type maintenance equipment as well.

M.

[minaret]

I recently installed one of these in my engine room. It's strictly for tools and spraying, obviously cant dive with it. Most dive compressors are very expensive, not only because they need to be completely oil and contaminant free, but because they are hitting much higher pressures than a shop compressor. They are really two different animals. I would not use a dive compressor to run tools when I can do the same with a much cheaper compressor like this one, and then replace it when it dies. H.P. is a pretty useless measurement for a compressor. This one delivers 4.2 CFM at 90 psi, which will run most air tools. I wouldn't try to push a 2 qt. pot spray rig with this, but it'll run a touch-up gun on a fair-sized shoot. I shopped a lot and this was the smallest unit I could find that cranked 4 CFM minimum, plus I've had good luck with the brand over the years.

Amazon.com: Makita MAC2400 Big Bore 2.5 HP Air Compressor: Home Improvement

[djmarchand]

Jeff:

My Husky 2.0 SCFM unit has a 1.75 gallon air receiver built in. The receiver gives it some dampening capacity and lets the compressor cycle as needed. I researched the specs pretty carefully to come up with a compressor that could be powered by an inverter for 15 minutes or so to clear a fouled prop.

The original Hookah rig came with a plastic air receiver of about 5 gallons and a POS (not Brownie) 12 V compressor. The plastic air receiver was rated for 30-40 PSI, so that is what I set the Husky at.

It puts out enough air for reasonably strenuous work at keel depths. Setting the air compressor pressure regulator at 30 PSI helps because if you set it at 100 PSI you are just wasting energy as you compress the air up and then regulate it down to your mouth which only takes a couple of pounds at keel depths.

In so far as the 2 SCFM spec (which is at ???? discharge pressure) I recall from my scuba course of a million years ago that a relaxed diver uses about 1 SCFM. I know that I can go for more than an hour on a 72 SCF tank. So double that rate and you can deal with some excercise.

I haven't bothered with a filter, but if I was going to use it a lot, I would add one. Both a particulate filter and a charcoal canister to trap any hydrocarbons would be a good choice.

David