Compressor for body work

[awave]

What is a good compressor for doing body work using air tools- sanding discs, etc.

How many SCFM is needed? Compressor recommendations?

[mepstein]

Look and see what are the requirements of your air tools and maybe a blast cabinet if you need one.

[ChrisHamilton]

Originally Posted by awave

What is a good compressor for doing body work using air tools- sanding discs, etc.

How many SCFM is needed? Compressor recommendations?

Too small a compressor will have to work too hard to keep up. It will result in a lot of water in the lines. Just as important as a good compressor is properly setup airlines that allow the compressed air to condensate before the filters. Super important if you plan to paint. Just the cost of paint and having to redo something nowadays should be motivation enough.

As for the question the minimum to run air tool, spray guns etc IMO is a true 5 HP 2 stage compressor. Many of the box store compressors claim to be this but in reality are not. A good compressor is not cheap these days either. If you are going to paint an 80 gallon tank is almost mandatory. You can get by with a 60 gallon but an 80 gallon is much better. A compressor rated at 15 SCFM is the absolute minimum for trying to do any spraying or using a random orbital or dual action sander. More capacity is always better.

Here is a pic of what a proper basic air line layout should look like. Very important if you plan to paint.

[2.7RS]

Bigger is always better.

Vertical compressor will save shop room

[Dpmulvan]

Forget HP and PSI useless marketing, it’s all about the CFM’s. Chris is right anything under 15cfm is useless.

[Dpmulvan]

If had to buy another I would spend the extra dough and go with a screw compressor.

[ChrisHamilton]

Originally Posted by Dpmulvan

If had to buy another I would spend the extra dough and go with a screw compressor.

Screw's are quiet but everywhere I worked that had one we had trouble with them and almost no one understood them enough to fix them. Had a big IR screw and when it went down we called IR and they sent a Tech out at $200/hr. He "screwed" around with it all day, like 6 hours and then pronounced that he had no clue what was going on. We got a bill for $1200+ and nothing was fixed nor did we have any idea still what was wrong. Luckily a friend of the Owner who was a plant maintenance tech for many years, came by one day and took a look at it and had it running in 15 minutes! I can't remember what the issue was but they are complicated and not that reliable in my experience. Your experience may vary but I've seen enough that I don't want one for my Shop now that I work for myself.

Current one I have is a 7.5hp 2 stage 25 CFM IR with an 80 gallon tank. Good compressor but it's loud. It does all I need it to do though so I can't complain too much. My next compressor will be a Saylor-Beall. One I'm looking at runs at around 700 rpm (= quiet) and puts out 35 CFM. When I build my new shop that is what I'm going to put in it. Not cheap though but it will last for many many years.

[962porsche]

in my shop I have a few air compressors one was a screw drive for the paint shop and the other was a 20HP 3 cylinder piston for the body shop and a 15HP twin cylinder for a backup.
all were very reliable and never gave me a problem!

after I retired I moved the 15HP to my personal shop and I have a 7.5HP 3 cylinder as my backup.
the 7.5 is ok but will run hard for high uses air tools but does kind of keep up.
at my house I have a husky 80gal 3 cylinder 5HP. it works good for my needs at the house.

[Dpmulvan]

What air dryers are you guys running for paint?

[mepstein]

If you are just doing one car, think about buying electric tools and rent a compressor when you spray the paint. Buying a good amateur/light pro compressor and all that goes with it is pretty expensive.

[ChrisHamilton]

Originally Posted by Dpmulvan

What air dryers are you guys running for paint?

I've got an Ingersoll Rand unit rated for 35 CFM. Got a great deal on it used a few years ago. Don't know why I didn't get one sooner. That being said, even without a refrigerated dryer, properly setup air piping with sufficient length before your filters will work well. Especially if the compressor is not overworked. I still run the same filters in this order, water coalescer, oil coalescer and a 2 quart desiccant filter. Before I got the air dryer I would bake my desiccant in the oven at home to renew it. Key to a water free system though is setting up the piping correctly.

If you get a desiccant dryer stay away from the ones that use packaged desiccant as it is very expensive to replace and desiccant only lasts a few days really. Devilbiss DAD-500 refills are what I'm referring to. If you get a DAD-500 fill it with loose desiccant then you can bake and renew it and save a lot of money. Arrow Pneumatics makes several good desiccant filters and are much more affordable than the Devilbiss one. And Arrow sells 2 quarts of desiccant for around $25 through Zoro Tools IIRC.

[Dpmulvan]

I’ve got a homemade system of copper pipe, a desiccant filter made out of a culligan whole house water filter, a few more traps and then an engine guard filter for painting. Not pretty but it works well, cheap and you can reuse the desiccant.

[Bill Douglas]

Originally Posted by Dpmulvan

and you can reuse the desiccant.

Yep, I tip the used desiccant into a stainless steel bowl and hit it with the hot air gun. Much easier than replacing it.

My compressor is a 3hp engine with a fairly largish tank. Using it with the Devilbiss Prolite https://www.autorefinishdevilbiss.com/products/prolite/prolite-gravity.aspx works well and have never been short of air.

I use the compressor with the (small) plasma cutter and odd jobs around the place like burr grinder use and it works fine for that too.

[dennisO]

Resurrecting an old thread, since I'm looking for a new compressor for my garage. I need it for air tools and eventually to paint a car. I see oil-free compressors and oil-cooled compressors. Is oil-free best for automotive painting since it helps reduce the possibility of contamination, or can oil-cooled be used?

[Dpmulvan]

Originally Posted by dennisO

Resurrecting an old thread, since I'm looking for a new compressor for my garage. I need it for air tools and eventually to paint a car. I see oil-free compressors and oil-cooled compressors. Is oil-free best for automotive painting since it helps reduce the possibility of contamination, or can oil-cooled be used?

Oil cooled can be used you’ll filter air anyway. Most lower end ( big box store) oil free compressors won’t put out enough CFM’s for paint. Get something with at least 15cfm.

[dennisO]

Perfect - thank you!