How big of a compressor do i need?

[rc51kid]

I am thinking of spraying my roof with a coat of auto paint. I have no room for a big shop compressor. I could use a little portable bompressor for house projects such as a nail gun. If a small or smallish compressor would work for spraing the roof that would be great. How many gallions do i need for spraying jobs like just a roof?

 

[gregnash]

I was recently researching this and from what I gathered you want something that does at least 8-10 cfm at minimum depending on the needs of your sprayer. From there you will want a large enough tank that it will not be constantly "playing catch-up" while you are spraying.

 

[rc51kid]

Thanks for the info. I will look at that. I guess i was looking at the size of some compressors. Something like a 15 gallon less i could possibly put down in my crawlspace when not using it. But i dint know if something smaller would be stupid to use for painting.

 

[gregnash]

From what I have read size does come into play but not near as much as the CFM output. The tank doesn nothing more than store up a compressed air and the larger then tank the more time you will have between the system having to cycle and refill the "void". You definitely don't want something that is so small that it is constantly trying to keep up with the usage but at the same point you want to be aware of the output capabilities of the compressor. You could always go into somewhere like Sears, Lowe's or Home Depot and look at the compressors and ask an associate what is the smallest compressor capable of keeping up with the job of automotive painting.

 

[JCruse]

I have NO IDEA what you need to use, but, I was repeatedly told the same thing (7CFM or higher) for shooting bedliner on a storage drawer build. One person however told me that I could use my little 6 Gallon 3CFM pancake compressor, so I did and it came out fine. Great actually. I just paused for a few seconds every minute or two to let the pump catch up some. I have NEVER shot paint with it though, so...

 

[gregnash]

Difference with paint, from my understanding, is you need the extra CFM to help atomize the paint for a lighter fogging effect. With bedliner you want to throw it somewhat clumpy/thick which is the complete opposite of auto paint.