Air Compressors

[timbo]

G'day all,

I'm thinking I'll soon be in the market for some sort of air compressor with assorted tools, bits and pieces.

I would mainly want to use it for spraying paint on body panels or similar jobs, and probably also for air wrenches etc.

I'm wondering what sort of CFM should I be looking for, and how large a tank capacity? I want to be able to say, spray a panel or two before I have to stop.

I was just looking at a 2.5hp compressor that pumps out about 9CFM. Would this do the job? What sort of quality control checks should I look for in buying one?

I was thinking of using it for sand blasting as well, but I'm not so sure about it after being warned about silica inhalation. I'm thinking of hiring a wet sandblaster for that job.

[Motorhead]

Mine is

3hp

14 cfm

150 psi max

50 litre tank

no problem for spraying or air tools, but wether its the gun the media or the compressor it doesn't like the hand held blasting guns, just doesn't work.....not sure how those blasters you see in the back of mags would fair though, they reckon they work from 60psi -100psi

Brought mine from machinemart a few year back , one thing though even though its 240v and came with a plug, I've had to wire it direct to its own breaker it kept blowing 13amp fuses, I did take it back but was recommended to wire direct....its worked no problem since

[timbo]

have you got a regulator? maybe the psi was too high? or the paint not thin enough?

edit: sorry, I misread. blasters, got it.

[Motorhead]

yes its got a regulator...you misunderstand, spraying paint and air tools work perfect (air ratchet, air gun, air saw, shutz gun).....its blasting with a hand blast gun that doesn't...

There's a picture of the blast gun in the product review section on my site...and a few comments on it..

[cols110]

I`d say 9cfm would be on the small side, the biggest you can afford is the way to go. Waiting for a compressor every few minutes to build up pressure is very annoying, better off getting a bigger one first off. 13-17 would be much better, some air tools really chew thru the air, die grinders etc, if your planning on using these sort of tools you want as much air as you can get.

[timbo]

so even with a 50L tank, you still have to wait every few minutes?

btw, if it makes a difference, which I think it does, this particular one is belt driven.

[timbo]

read your product review motorhead. Do they make gravity fed ones? reckon it would make a difference?

[Niall_CSK]

As Motorhead says that's the biggest you can get on a single phase 13A supply.

I got an upright cylinder one a company down south, if I remember correctly it was just under 400 quid delivered as well.

Screwfix supposed to do one very like it but can't find it on their website.

The upright has a twin V cylinder direct drive that sits on top of a 100l, sits in the corner & purrs away quite nicely. It has three outlets, one at cylinder pressure direct, one through a regulator for spraying etc. and the last via a retractable air line mounted on the frame. It sits on four points but still has two wheels so I can move it if I need to. It does everything I can ask of it, hasn't failed me in two years so I can't ask much more, recommended.

The previous one I had a passed on to a friend after 10 years service it was a bit down on power for my little blast cabinet and the horizontal cylinder arrangement meant it stuck out at the end of the bench and I kept falling over it. Also sitting on two wheels and one rest point it used to go walkabout when run for a long time.

Forgot to say it's 3hp 14cfm and I have used a total loss free standing 2kg blast pot as well and the pot runs out before the compressor losses it.

[Troddenmasses]

I have a 14cfm, 100L, belt driven compressor from SIP, and am very happy with it. The belt driven bit only means that if the motor burns out in the future, you will be able to fit a new one. I agree, go for the largest CFM and tank that you can afford. I used

world of power

For mine, and they seem to be the cheapest that I can find. Don't believe the figures that you read on air tool boxes, though. The die grinder from machine mart says that it uses 4 cfm. All I can say is that it empties my 100L tank in about a minute, and when the compressor kicks in, it can't keep up, so I have to wait for a little while to let the pressure build back up. Spraying should be no problem, but you will need either an oil and water free type compressor, or a seperator on the line.

[andyb]

I got a second hand one, can't remember make. I had to change the motor to make it go again.

3hp motor, 150psi, 150 ltr tank and 14cfm (free air). Good for anything, rattle guns, DAs and spraying.

Also don't forget the size of the pipe to your tools (Ooeer ) will have effect. The 8mm id tube from MM isn't worth it, you need 10mm at least.

HTH

[JST]

i paid just under £200 for a 2.5hp, 50L one 12cfm from Mole Valley. Northern Tools and Machine mart are worth looking at. Machine mart seems to have the best options. upright ones seem to be more popular now, or at least gaining in popularity.

if i purchased again i would get the same spec but a 100L tank - although that takes alot of room.

make sure you get a decent air hose as well - eg 10mm internal bore i would recommend.