View Full Version : compressor size for blasting


Camaro16
04-13-2009, 09:58:10 PM
What size air compressor is needed to run a sandblaster? And what is the best material to clean rust off?

TIMMYS81-Z
04-13-2009, 10:20:39 PM
I've got a husky 60 gallon compressor and a harbor freight blaster and they work great together with some cheapo play sand I bought at Lowes.
Just make sure you have dry air lines.Any moisture whatsoever will make the blaster shoot nothing but wet air! Ask me how I know!:)

BTTB71SS
04-13-2009, 10:27:02 PM
I have got a Porter Cable 80gal model c7550..It does run alot when sandblasting but one thing to make sure is that you drain the tank after each day to prevent rusting from the inside.

I also would recommend a inline dryer to keep as much moisture out of the lines as possible..

rustover
04-13-2009, 10:42:42 PM
I use a blast cabinet. I would say the smallest would be a 5hp running, not peak. I also have an 80 gallon unit. I would say that 16 and up cfm will do the job. Mine is an 18.1 and runs a lot. I will eventually catch up and cut off. The manual said it was designed for continuous duty and not to let it cycle more that 6 times an hour. As far as blast cabinets, you can size the nozzle to your cfm output.

BondoSpecial
04-13-2009, 11:48:59 PM
HUGE. You can't possibly have enough compressor for a sandblaster. 100 gallon 2 stage compressor, is not too much for a blaster. It will still run!

jroach
04-14-2009, 12:21:47 AM
my blaster needs about 80 psi and my 30 gal 3.5 horse craftsman runs constantly

Rick WI
04-14-2009, 12:31:55 AM
5 HP 2 stage if you really want to do some blasting. My tank is 80 gal.

Sand or black beauty for cleaning rust.

Eliminator SS
04-14-2009, 01:06:33 AM
Here's my answer to the question "how big of a compressor should I get for blasting?" The biggest you can possibly afford. I have an 80 gallon with a monster of a motor on it and I still give it breaks when Im blasting stuff. I've ran it so hard at one time that I turned all the copper piping running from the motor to the tank blue/purple from how hot the air was.

buckeye79
04-14-2009, 08:51:16 AM
Mine is a 2 stage 60 gallon, which keeps up but you still need to give it a break now and then

71 Camaro
04-14-2009, 02:00:18 PM
my 5hp single stage is NOT big enuff. it runs like crazy and still have to let it catch up.

btw if you use play sand wear a respirator, the dust from that shtuff is very deadly....or so ive been told.

Keizer
04-14-2009, 04:00:55 PM
Here's my answer to the question "how big of a compressor should I get for blasting?" The biggest you can possibly afford.

But, if you can only afford a five gallon compressor, that advice is a disaster waiting to happen if you are using it to sand blast. It will kill it.

I would find out exactly what the demands of the sand blaster will be and buy accordingly. Usually the demands of a sand blaster require a compressor that can handle allot of CFM, and a large tank so it isn't turning on and off allot.

76_TypeLT
04-14-2009, 11:20:55 PM
my 5hp single stage is NOT big enuff. it runs like crazy and still have to let it catch up.

btw if you use play sand wear a respirator, the dust from that shtuff is very deadly....or so ive been told.

100% correct - silica dust will mess you up.

a550550
04-14-2009, 11:41:35 PM
I use black beauty blast material. Works great.

As for a compressor, I use a 3 cylinder 7.5HP 80 gallon. It really depends on the CFM of the compressor, and what pressure the CFM is at.

Mine puts out 25 CFM at 125 PSI, the max most pot blasters are rated for. It keeps up, but not a cake walk. It maintains about 90 PSI with an 1/8" nozzle.

So my advice--either buy a big enough compressor to run your blaster, or just rent a gas powered when you need to blast. Nothing is worse and more frustration than trying to blast without enough air

earlysecond
04-15-2009, 07:04:52 PM
The real problem I have discovered the following:

When I finally work myself up to go get all the clothes and the safety equiptment on and crawl into my small blasting booth. . .I want to get it all done and get out of that environment ASAP. I want everything done yesterday, damn the torpedos and to heck with giving the compressor a deserved break. I want to get it done! I want to pick the crap out of my ears and eyes and be done. . .did I mention that I want to get it overwith?

Waiting on the compressor is a drag. I have a 5hp/7hp 230 volt peak compressor with an 80 gallon tank, single stage. I also have a CLARKE pressurized blaster with a 100lb tank in which I use black beauty. My compressor is sorely underpowered for this task. I actually blew up a similar sized Porter Cable model (keep your air filters really clean) I spun a bearing and turned the air outlet pipe out of the head into a molten high pressured explosion. I take the issue seriously. Blasting, epecially and type of prolonged blasting, requires a HUGE CFM rating! If you are going to blast with anything bigger than a small cabinet, you cant rely on a small oiless unit. I almost agree that you might be better off to rent a gas powered unit that is trailer mounted for a day and have a marathon. You could literally blast a whole car and components in a day if you had enough air. Air, more specifically CFM is the limiting factor to all blasting I have done.

Brent

76_TypeLT
04-15-2009, 10:29:40 PM
It's amazing to hear how some of these really big (and pricey) compressors can barely keep up (or can't keep up). It's like you need an industrial sized $4000 compressor, which is simply unrealistic for most folks. What a bummer...

GetMore
04-15-2009, 10:56:03 PM
Sand blasting uses a lot of air. I should say it uses a LOT of air.

My boss has sandblasted a couple of cars at the shop, and he rents a big compressor when he does it. Even two good sized two-stage compressors can't keep up with extended use of the sandblaster.

Now, if you've got some time or a small sandblaster you can do it with a regular compressor. It'll just be inconvenient.

Just what are you blasting, anyway?

BTW, my boss does have a two-stage compressor for sale, but it uses three-phase power.

earlysecond
04-15-2009, 11:21:13 PM
Aaron,
Do not let us talk you out of this. Just do not expect to hook a $250 compressor to a decent sized blaster and expect that you will be able to blast for more than half an hour or less without resting the compressor. I must say that in a half hour, you could blast a bunch of stuff. I have stripped a whole camaro hood on both sides in about that time, except for the factory primer which is nearly impossible to remove on some cars.

If you want to run a large blast cabinet or a really small pressurized blaster you will probably be ok. Use common sense and rest the compressor, make sure, based on my experiences, that you are blasting in a totally different room than where your compressor is breathing the air. Additonally do NOT scrimp on safety equiptment. High speed abrasives are dusty and fly into your eyes/ears/mouth anything that you do not cover.

Brent

76_TypeLT
04-16-2009, 09:49:39 AM
Aaron,
Do not let us talk you out of this. Just do not expect to hook a $250 compressor to a decent sized blaster and expect that you will be able to blast for more than half an hour or less without resting the compressor. I must say that in a half hour, you could blast a bunch of stuff. I have stripped a whole camaro hood on both sides in about that time, except for the factory primer which is nearly impossible to remove on some cars.

If you want to run a large blast cabinet or a really small pressurized blaster you will probably be ok. Use common sense and rest the compressor, make sure, based on my experiences, that you are blasting in a totally different room than where your compressor is breathing the air. Additonally do NOT scrimp on safety equiptment. High speed abrasives are dusty and fly into your eyes/ears/mouth anything that you do not cover.

Brent

Good stuff, really appreciate the info. My real issue is that I just don't have the room for a 60/80 gal monster compressor, unfortunately. I can get smaller tank compressors with really high CFM and good HP, but sounds like I'd have to take my time as not to blow up the compressor, which I could live with. I am luckily not on a strict time schedule.

The only things I would want to sandblast are the frame, A-arms, etc. I won't be painting my car myself (yeah, yeah :D) but might strip the body panels to save some dough. If so, then I'd likely soda blast those parts, which is not as demanding on the compressor if I understand it correctly.

Good call on the safety equipment - I was looking at Eastwood and they have some hoods and other gear that would be worth getting. It just seems like a good idea to wear that stuff. This was a really good thread - learned a lot.

POS71RS
04-16-2009, 12:02:13 PM
... If so, then I'd likely soda blast those parts, which is not as demanding on the compressor if I understand it correctly.
...

Why so? I was under the impression that sodablasting was higher pressure...
I figure it was the same or more required of the compressor.

76_TypeLT
04-16-2009, 01:51:49 PM
I am sure I just mis-read something. I thought the CFM requirement was less for soda than sand, which is more meaningful, right? I am still expanding my knowledge about compressors, so pardon my ignorance.

earlysecond
04-16-2009, 10:50:05 PM
Don't apologize for learning. You are doing due diligence and you will be informed to make good decisions. We may have you pretty scared at this point but if you are going to blast anything bigger than brackets and suspension parts you need a good bit of CFM. Do not get me wrong, I have blasted EVERY part of cars I have worked on. I have never found a better way to strip paint and gunk. Some will agrue that you shouldn't sand blast body panels but I still have not seen significant proof that they get warped.

I must point out that other body tools are serious air hogs as well. Inexpensive Dual Action sanders (DA's like the one I have), inline sanders often called air files, and EVEN die grinders have an appetitie for air.

Match the CFM requirements posted on your tools to the compressor that you will need. BEWARE that the compressor manufacturers stretch the minimum data to the LIMIT.

Good Luck
Brent