So I am almost ready to start stripping my car down, but I don't know what size of compressor I will need to run an orbital sander. Craftsman has a nice sander for about 80 bucks but doesn't say a recommended compressor usage. It says that its avg air consumption is 4.0 and I am assuming that is psi per minute? So would a 33 gal comp with 1.6hp and 150psi be enough to use to sand, paint, use air wrenches, die grinders, etc? Tell me what you guys are using. Thanks.

 

My dad had a pancake compressor that ran out sanders and die grinders. We now have I think a 30 gallon compressor. Most things that use a compressor to run recommend a certain SCFM. You could look for a compressor that has more than that and it will work. I can get company name and stuff of the compressor we have.

 

My 60gal, single stage 5 horse was not enough to keep up with the sander, so i went the electronic using a 4 1/2" angle grinder and 60 grit flap disks. I think i used 4 disks on the whole car

 

I've got a 6 HP 21 Gallon compressor, and while it will run almost anything, it won't do it for very long. If you start using an impact or angle grinder for any amount of time it runs down the pressure and you have to wait for it to build up again. I would get something that might seem like overkill at first, you'll probably be more happy with it in the long run.

 

My understanding of compressors is they have three primary statistic you are concerned about.

Power - how fast it can pump and fill the tank
Pressure - how many PSI it can produce
Tank size - volume of air it can hold

If you have a small tank, you need a pump that will refill really quickly or a constantly running air tool will drag it down and it cannot catch up. Small tanks work pretty good for air nail guns, but suck for air paint guns, die grinders, and other tools you are going to use for long periods of time. A larger tank will help with that, but you can still drain it if your pump cannot keep up. Typically, you want the pump to be strong enough to cycle and not run all the time. Also adjusting the psi output for what the tool requires will help save air supply. Like BA said, all these factors affect the scfm@psi.

A quick look at Home Depot shows die grinders and air sanders need about 4cfm@90psi. Sounds like you should be looking for a compressor in the 30 gallon 2hp range to get 5.5scfm@90psi, but check the specs for your specific tool.

 

We painted The 66 and our HVLP gun needed 10 CFM.
We used 2 smaller 110v (4 HP and 1.5HP) compressors and connected the air hoses to a TEE at the water trap input. The output from the trap went to the spray gun. We made sure they were on different circuits so it would not trip.
Never had the pressure at the water trap drop when spraying.
The most important thing is the CFM of the compressor needs to be at least equal to the tool at the tools operating pressure (PSI).

 

Get the biggest one you can afford / store. When it comes to compressors I am of the belief that bigger is definitely better.


+1 on the electric sanders, grinders etc.