The Stovebolt Site Forums The Shop Area Paint and Body Shop Compressor or not??

I am looking for some advise on a compressor.
I have been debating wether to upgrade my existing compressor to something larger. I am weighing the options of being able to do some sand blasting and also some painting of my truck, compared to paying for it to be done. I would like to be able to prime and possibly shoot a bottom coat of paint in preparation of having it finish coated. The question I have is what would be the minimum gallon capacity and CFI requirements at what pressure? I don't have 3 phase available but do have a 100 amp 240 volt service in my shop.
Any advice would be appreciated.

Man this get discussed a lot. Searching the site using compressor as the search term will get you hours of reading. The short answer is to take the CFM requirement of the largest air hog tool you will use and buy a compressor that matches that "continuous". For example if your highest requirement tool uses 12CFM @ 90 PSI you'll need a compressor that has at least that rating continuous.

Agree with what Tiny said above. Minimum Ingersoll Rand Single Stage T-30(or now they call it a SS5L5, 5.0-HP, 60-Gal. Vertical 18.1CFM@90psig, 135PSI max,230V,60amp,single phase) A step up would be a two-stage 2475N7.5-V 7.5HP 80-Gal. Vertical 24.0CFM@90psig 175PSI max,230V,60amp,single phase. 3 Phase would cost a big nut to have brought in, New panel/line wire, don't think it would be worth it. Niether one of these would sandblast a car, um truck, but would blast a bunch O truck parts and would paint a truck without a problem. We have had a SS5L5 for 15 years and no problems-it's used 5 days a week/10 hours a day. Now I know I will get a lot of input on this , but we used plastic PVC - rated at 600PSI - for our air lines so we could add lines as needed. At 600 Psi we will never reach the max as we run 100 psi on any given day. Knock on wood never a problem.

Thanks guys, I would think the money I would save doing some blasting and painting myself would pay for the equipment purchase....at least thats what I will tell her....
I am an electrician and yes to get 3 phase to my shop would be way to costly.

Thanks for the advise guys....I had tried the search bar to the left of the screen with not much luck. I just realized there was a search bar up top which I tried and found all kinds of info. Still feeling my way around this site and appreciate your patience.

By the way, when you use PVC do you use a solvent to connect fittings or that push fit system?

Mark

I've read some horror stories about PVC failing. I know a couple of shops that used PEX to plumb their compressed air with good success so far. I used 1/2" black iron pipe.

Worth Reading

I bought a "PUMA" 240V 3hp running 6hp rated. Puts out 12CFM at 90PSI. It works great for painting barely will operate a 90lb Harbor Freight sand blaster. You have to use the smallest tip. Also run the sand through a screen or small pieces will plug the nozzel. I have done my whole project frame, cab, etc using this. It's slow and cumberson. You need probably twice this CFM at 90PSI to have a good sand blast experience.

Solvent, there are 2 type thin and thick wall-use the thick it's rated over 600 psi

Think about what will happen when PVC bursts. It will shatter and fragment. PEX will burst and stay together.

For information on compressors, here is one dealer that gives advice on compressors. Look at some of the descriptions on his compressors.
http://www.eatoncompressor.com/catalog/item/504747/172983.htm

Just as another point of reference, I ran 3/4 inch copper for my airlines. It's pricy, but I already had some laying around, and it sure is easy to cut and solder together.

Looks sharp too.

Kurt

I bought the Ingersoll-Rand 60 Gallon twin cylinder machine. Bolted to the floor.
I was in the middle of body work on the 51 panel ...... when ....

It threw a rod one month AFTER the warranty ran out ( hardly used in that time).

The good news is that a guy from Ingersoll-Rand CAME TO THE HOUSE! Looked
at the block and the bad rod and declared it was a badly cast rod. They charged me only for the house call, he completely replaced the compressor unit on site, tested it, & re-set the warranty to new!

Great customer service. A lot to be said for that ......

What type of copper did you use. I would be worried about splitting it open with to much pressure.

please read my post in the toolbox before buying an IR air compressor "new air compressor bought wrong brand" before buying your compressor. although now that its up and running it has worked very well even with the blast cabinet.

I used type K, which is the thicker wall. Here is an excerpt from the "Copper Tube Handbook" with a table of pressures.

Rated Internal Working Pressures for Copper Tube: Type K

I think you will see that the working pressure is higher than you are likely to use.

Kurt

Leaving price differences out of it for the moment...
I read on that chart the 1/2" is rated 291 lbs higher than the schedule 40 PVC which is only rated at 600 psi. Which will fail first at 120 psi?
How long (approx) would it take for the PVC to fail?

I think the point is that if the PVC fails, it will fail explosively. It will throw out shards that can injure you. If copper fails, it will either split, or a joint will pop loose, but no missiles. A hitch in the day, but not fatal.

Kurt

I've also read that the oils in a compressed air line can soften PVC and cause failure. That was the deciding factor in me using black iron piping for my runs.

I wouldn't have thought PVC would fail that way. Clearly it does.

http://www.osha.gov/dts/hib/hib_data/hib19880520.html

How about black iron or galvanized pipe? Less $ than copper, easy to make up with fittings from Home Depot/Lowes etc.

Sure, Iron pipe will work very well.


Kurt

Thanks for all the advice guys. I am going to do some more looking around for the compressor and think when the time comes I will use the black pipe to install the lines.
I have been looking through some used equipment sites and have found all different types out here. The only thing that worries me about buying to old is now I would have 2 restoration projects....parts could be an issue.

There is a company caled RapidAir that you need to take a look at for your air line use. The good thing about it it is cheap and you do not need a pipe threader or pipe wrenches to install the system. and Zero Rust problems.
62Blue
Don

Thanks Don, I will check that out.