Air Compressor Specs.

I am building a sailboat and I am about ready to paint the hull. I have spray guns and paint but I still have to buy, borrow or rent an air compressor. But, when I have gone to look at them, it seems that the smaller compressors are not specified for running a paint gun. The bigger compressors in the $500 and up range will obviously do the job, but I am hoping to spend less. When I have asked sales clerks they say a smaller compressor will do the job. But, I don't have confidence in their "sales pitch." I would rather hear some advice from those who have actually painted a boat or car or something and has an opinion based on experience. Is there a minimum horsepower I should look for? A minimum holding capacity? etc.<br />I don't want to compromise and then ruin my paint job. But I also don't want to spend money I don't need to spend. Any thoughts?

Re: Air Compressor Specs.

It really depends on the sort of spray epuipment you have. I would go to an automotive paint store a quiz them, they sell the spray equipment and should be able to help with compresser specs. Not necessarily in hp, but in "cfm". That's cubic feet/min. of air delivery. Someone may come in here that has the numbers rolling around in their head and post them, I certainly don't. I think you're gonna hafta spend more than 400bucks for the right air supply. Chief

Re: Air Compressor Specs.

Size of the compressor (CFM) and the size of the air tank are major considerations. A boat has alot of surface to cover so you don't want to run out of air at a point where you don't want to have to wait for the compressor to catch up. Unless you can do the painting in small sections, you will need a good size unit. Don't waste your money on a direct drive unit either. They simply don't last and are extremely noisy. It sounds like you should get your boat prepped, and then rent a big compressor. You won't be sorry. Be sure you get one with an air dryer. Without it you will spray moisture beads and ruin an otherwise nice paint job. My shop compressor is a 4HP and is marginal for painting cars so have an auxiliary tank connected to it for additional volume.

Re: Air Compressor Specs.

Air tools generally have a minimun required SCFM for a given air pressure listed in their packaging and or paperwork. Make sure that is covered and then some.

Re: Air Compressor Specs.

The alternative to a small compressor is a smaller gun. Some use touchup guns on tiny compressors. Look at the cfm of your compressor and buy a gun with cfm that fits.

Re: Air Compressor Specs.

a good gravity feed HVLP gun the kind with the cup on top is gonna use alot less air than the "old style" suction type guns the kind with the cup on the bottom.<br /><br />Body shop type air tools use more air, by the nature in which they are used, when in use, they tend to be on more than they are off. <br /><br />I would buy the biggest one I could afford, make sure its a belt driven two stage pump with at least a 220v 6.5hp motor and a 30 gallon tank of a name brand type. CFM specs can differ by a wide margin, depending on how the manufacturer measures it. You also need to think about how much your going to use it, look at the duty cycle rating, one with a 50% duty cycle needs to "rest" an equal time as its working, one with a 100%duty cycle need no "rest" at all meaning and can runn constantly without burning up. Like upinsmoke said, Do not buy a direct drive "oiless" compressor. They are made for the homeowner that wants to pump up a tire once in a while, or maybe run an impact wrench on an infrequent basis, they don't last, and the term extremely noisy is an understatment.<br /><br />also there is "self leveling" paint out there that can be rolled or brushed on. The boats I have saw done this way ended up rivaling ones that were spray painted, in other words they looked real good when finished. And you wont have to buy a compressor.<br /><br />A good compressor thats gonna do what you want it to do is gonna set ya back 500-700 buck on the low end. (at least for one thats gonna last a long time) There are cheaper ones but they arent that good. Unless your not gonna use the hell out of it. But if you are get a good one <br /><br />by the way how bout some pics of that boat??

Re: Air Compressor Specs.

Nobody has asked yet..hmm...Sailor..what Paint are you planning on ?<br /><br />Just to let you know..Ive sprayed many of 40' boats with Gel-Coat using a Craftsman 5hp 20gl tank and a 2 gal or 2qt pressure pots from Binks with a 2001 binks gun.( there are now better guns out there with less overspray saving material cost )<br /><br />I would think a 5hp 20gl compressor would do you fine (again..depending on what your spraying)

Re: Air Compressor Specs.

Here's some additional numbers.<br /><br />Speedair gun #2Z364A. 2.5-6 cfm @ 30 - 50psi. Bought and specifically used for production gelcoating new hull layups but can be adjusted down for thin LP. Also originally used occasionally with a Craftsman 5hp single stage compressor with 20 gal tank. Now used on a cheap 4 cfm @ 90psi HarborFreight type compressor with 8 gal tank for paint.

Re: Air Compressor Specs.

Thank you very much for all the advice. <br />I will do some thinking on all of this. Several friends have offered their compressors - but I think they all have small units. <br />JimmytheKid, I will try to put some photos on here. Don't I have to put the photos on another site and link to them?<br />I have not ever really understood how you put a photo in your message.<br />jerry

Re: Air Compressor Specs.

Sailor 3X7 you can get plenty of air supply by hooking the hose up to two of your friend smaller units same time. Just make sure they get their power from 2 circuits in house. My father did that, no problem.

Re: Air Compressor Specs.

BillP,spraying gelcoat question!Have you ever resprayed boat,spraying gelcoat over old gelcoat?<br />I was thinking about doing it to my sportsfishers cockpit.Paint will not hold up to time were the action is.

Re: Air Compressor Specs.

Originally posted by prockvoan:<br /> BillP,spraying gelcoat question!Have you ever resprayed boat,spraying gelcoat over old gelcoat?<br />I was thinking about doing it to my sportsfishers cockpit.Paint will not hold up to time were the action is.

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Yes, a few times on small boats. Prep with 250 grit and take meat off. Thickness over 40 mils or so stands a chance of stress cracking easier. Boat mfgs use 20-40 mils and measure it. I'm not up on gelcoats brands these days but some are more impact resistant than others. Tooling (molds) and medical grade (if they still make it) type is the toughest. If you are looking for a high gloss mirror finish the work just begins after you spray it. You might want to look into pigmented epoxy resin for the cockpit. It rolls thick and levels easy on floors.

Re: Air Compressor Specs.

If you can use an HVLP type gun. They use a lot less air and are very easy to use. I bought a binks a few years back and love it, never use a siphon gun again. Also, with my binks, you can interchange different tip for various viscosity paints. If you go this route, a 20gal tank will fit your needs just fine. 20gal is actually more than needed for an hvlp, but for the price, I would not buy one much smaller, then you can use it for other air tools.

Re: Air Compressor Specs.

Thanks Bill,I might try a spot first.I had rolled gelcoat,it came out great for nonslip areas.