The Stovebolt Site Forums The Shop Area Paint and Body Shop What size compressor do I need for Painting & SB?

I'm looking to upgrade my air compressor and I want to make a good choice.

I have my eye on something but want opinions first. It needs to be portable and big enough to handle sandblasting small things in my cabinet. I also want to do the bodywork, primer and painting, so please factor that in too.

I have my eye on a Speedway 125 psi 25 gallon tank with specs of 8.6 cfm @ 40psi and 6.0 cfm @ 90 psi.

Should I go bigger?

Bigger is always better, particularly where the reservoir tank is concerned. Sand/bead blasting takes up a huge volume of air, and sanders use a lot too. Look at the CFM rating at the low end of the pressure scale, like 25 CFM at 75 PSI, for instance. That's the spec that will determine how long you can run a tool before giving the tank a chance to build pressure again. I'd suggest a minimum of a 50-gallon tank, and 100 would be better. Of course, I'm accustomed to supplying a professional shop with several employees working, so a 100 CFM compressor capable of maintaining 100 PSI or more at full flow was what I considered to be minimum capacity. I ran two 20 HP compressorss with 300 gallon reserve tanks in the last body shop I managed. You don't need that much for a hobby operation.
Jerry

Would the compressor I mentioned above work OK for spraying primer and paint?

I believe you want closer to 12cfm @90psi in the 'painters' world.
If you only do a fender at a time you might squeak by with your proposed set up but for anything more than a few minutes your compressor is gonna run a lot and that makes heat and heat in your airlines makes water and water firetucks (sans the "iretr") your paint job every time... Water and oil vapor in the lines needs to be filtered out in any case.

OK, thanks. It looks like I need to save some money and buy a proper size unit. Otherwise I'll have regrets.

I just sold my 26gallon Husky 5HP in favor of a 60 gallon. You wont be happy sandblasting with a 25gallon unit.

I would spray for 1 minute maybe 45 seconds - let it recharge. PITA.

The painting it could handle better as it was a lower PSI, but you'd still have to stop occasionally - not something you want to do when painting.

While your saving start some R&D on some painters forums as to best setups, layouts, locations of traps and filters and the like. Keep your eye out for a used set up. The compressors are simple to rebuild compared to an engine and a good place to practice honing skills and working that ring compressor tool
Same is true for motors. Your can order them on line for a couple hundred or so. Or have it rebuilt.
Deals are out there almost with out looking. I got mine from a painter I was asking some advice from. He had it down in a basement with just barely enough room to wedge it out. Took three guys to get it out and two to wrestle it into place here.
He just wanted it out and gave it to me, I think reasoning, he'd just saved paying two guys to remove it and haul it away.
Ring set runs about $20 for the compressor and I made my own gasket for the head.

But don't let not having one now stop you. You can strip and prep per 'normal' regardless and just roll or brush on epoxy primer. I just mix up small batches as I go. Then by the time you've got the truck all in primer and you've done your body work and your ready for real paint you'll be all set up.

I don't think there is such a thing. Then again I guess that depends on how hoss you are.

Look at the CFM requirement of your cabinet and buy accordingly. A blasting cabinet will have about the highest CFM requirement of any tool you'll likely own.

I bought a used cabinet. The gun is exactly like this one.

It uses (15 CFM @ 80 PSI) and two 13/64in. (7 CFM @ 80 PSI) nozzles.

This is the cabinet.

As you can see, the cabinet is not very large, but I got it for CHEAP including a new bag of extra media. It has already paid for itself.

I just might try rolling on epoxy primer. I will research the process involved and save the painting issue for later.

I have a friend who owns an HVLP unit that he describes as not needing a compressor. I know nothing more, but he has offered to let me borrow it. Does that sound like something that is made for painting cars?

Turbine paint gun.
Its hard to beat rinsing out a roller compared to cleaning out a gun. And roller sleeves are cheap.

So you would recommend rolling on the primer. Great! I think I'll roll the primer.

Now, about the turbine HVLP paint gun. Is that something I should mess with when it comes time to paint?

I rolled on the epoxy as I went along, worked fine

Bill

I have a 2-stage turbine HVLP paint system from Accuspray. It is now sold by 3M.

The main advantage of any HVLP system is the savings in paint.

The advantages of a turbine system are
- no need for a compressor
- no need to worry about dirty air
- no need to worry about moisture in the air
- air is warmer - decreases setting time (can be a negative factor)

Bill, That thing is HUGE! I will need a "list of supplies to buy" so I can get my 65 sealed up. I'll assume you can use a paint brush to get in the corners.


TC, It sounds like I will want to use my friends turbine setup after all. Thanks for the advice.

yes it's big - all done with a roller and brush, epoxy primer topped with Zero Rust and Tremclad [Canadian Rustoleum] - if I'd used any kind of sprayer too much of it would have been on the ground

Bill

Bill,

Did you put the Zero Rust over the epoxy primer?

yes, it worked fine - the top half of daBus is aluminum, they told me not to use ZR straight over aluminum, so I used an epoxy rated for aluminum on the whole thing first, need to still abide by the re-coat window or scuff sand if the epoxy is totally cured

Bill

Seems reasonable, Bill.

I also like the idea of brushing/rolling epoxy primer. It will eventually be sanded smooth. Throwing away a brush or roller is faster, easier, and safer than cleaning a gun (no solvent, no disassembly/assembly).

Then that needs to be the minimum continuous capacity of the compressor you buy. My compressor is rated 18.2 CFM @ 90 PSI continuous and it's sure not portable.

I use a Husky Pro 60 gallon, 3.2hp, a 135 max psi. The compressor is made by Hausfeld Campbell, I picked it up at Home Depot on sale for $350.00. You can also catch the same compressor at Lowes called a Kobalt same company just slaps on a differnt decal and color. The compressor works fine for sand blasting and painting. I have never had a problem with using it for either painting or sand blasting. But it is 220-240 volt. So if you don't have a 220 run out to your shop you will have to run one. The compressor is well worth the investment. And it beats the heck out of rolling on epoxy paint. I use a devillbiss finishline priming gun and a paint gun HVLP. I gave a $125.00 for the set from TCP Global. I have painted 3 trucks and a car with them and they work very well.

We have purchased quit a few items from these guys over the years with no problems..... IRS auctions