basic sand blasting cfm needed

[paulmitchell1984]

Hi guys.

Iv currently got one of the small aldi special compressors which is ok for small jobs like small spray jobs or clean g stuff tyres etc.
But I'm now wanting to get a small shot blast for doing smallish parts engine block prob being the biggest for tables horse shoes etc.

Now I don't think my compressor will be upto the job so why should I be looking g at as a bare minimum 3hp motor and decent size air tank? Or bigger.

In the long run I would like to be able.to.use air tools aswell like sander polisher poss die grinder etc so may aswell prepare for the future.

Any suggestions?

Thanks

 

[rtbcomp]

I use 2 3hp belt driven compressors to drive a pot. You may get away with adding a 3hp compressor to your existing machine and use a 2.5 - 3.0 mm nozzle.

They will both be running continuously so the Aldi machine may not last too long.

The tank size isn't that important.

 

[paulmitchell1984]

Cool may look into that then..not fussed if it's running constant as it won't be for much work in one go.

Cheersd

 

[J.B. Welding]

If your not running the blaster for extended periods you can charge a large reciever before you start. That will buy you some additional time but eventually you will just get the output of the compressor(s) you are running off.

 

[brightspark]

a larger tank will get u a minute or so extra as it may pump up to 120 psi then cut out . then when u use it will drop to 90 psi before cutting back in so u are back to square one .a cheapy small ish compressor will soon overheat after its run constantly for over 10 minsjust buy a decent 3hp belt driven compressor and that will just get u away

 

[Chris Stevens]

Hi guys.

Iv currently got one of the small aldi special compressors which is ok for small jobs like small spray jobs or clean g stuff tyres etc.
But I'm now wanting to get a small shot blast for doing smallish parts engine block prob being the biggest for tables horse shoes etc.

Now I don't think my compressor will be upto the job so why should I be looking g at as a bare minimum 3hp motor and decent size air tank? Or bigger.

In the long run I would like to be able.to.use air tools aswell like sander polisher poss die grinder etc so may aswell prepare for the future.

Any suggestions?

Thanks

Get your blasting done professionally, its simply not worth spending the sort of money needed for reasonable air supply and blast equipment for occasional work.

If you have a pressure washer though, water blasting might be a viable option, which is a lot less costly, and nowhere near as messy.

 

[rtbcomp]

If your not running the blaster for extended periods you can charge a large reciever before you start. That will buy you some additional time but eventually you will just get the output of the compressor(s) you are running off.

I used to do that on Economy-7 and tried to arrange my work so the tank was empty at the end of the day. I had about 400 litres in all.

 

[paulmitchell1984]

That kinda of adds a cost which I'd rather not have..If I get the compressor for other jobs then it's kinda 2 birds 1 stone in a sence

I do have a karcher pressure washer but doesn't give the same finish for paint/powder coat on engine blocks

Get your blasting done professionally, its simply not worth spending the sort of money needed for reasonable air supply and blast equipment for occasional work.

If you have a pressure washer though, water blasting might be a viable option, which is a lot less costly, and nowhere near as messy.

 

[Chris Stevens]

I have a 3hp 200 litre compressor, and had a small blast cabinet at one time. Compressor was running all the time, and it took ages to do even small parts. Might be possible to get things working a bit better, but you would probably find you would only be able to blast smallish parts, and use an orbital sander for a couple of minutes at a time, unless you have either more powerful compressor, or much larger tank, ideally both. Have done some wet blasting in the past, and seems to provide a pretty good finish, without anywhere near as much mess as dry blasting outside a cabinet. Did have the option of a big 3 phase compressor earlier this year, which would have run a large blast cabinet very easily, but the space it would have taken up, and the fact I can easily get blasting done locally, meant it was a no go.

 

[rtbcomp]

Blasting can be difficult on modern paints, and the type of gun makes a big difference - those syphon guns aren't great. You really need a pressure pot.

 

[paulmitchell1984]

The one iv used on a friends compressor I think is is a pressure pot..long tube put shot/grit etc in seal top..compressed air forced into top and a valve on bottom where it is fed out and to your hose.

 

[brightspark]

The one iv used on a friends compressor I think is is a pressure pot..long tube put shot/grit etc in seal top..compressed air forced into top and a valve on bottom where it is fed out and to your hose.

that will give u an idea then of whats required and if its for u

 

[paulmitchell1984]

It gives me an idea of what blaster I want but he has an industrial compressor with a huge tank so no not really an idea for personal use

 

[brightspark]

It gives me an idea of what blaster I want but he has an industrial compressor with a huge tank so no not really an idea for personal use

what jet size is he using ?? a 3mm one. no matter how big the comp is your limited by your jet size on pot .will run easily on 28cfm a 6mm jet requires about 90cfm. i have both

 

[paulmitchell1984]

Nossle looks to be about 4-5mm but not actually measured it.

Cheers for the comparison. .It will be mainly fine grit that's used so assuming I can get away with smaller nozzle 3mm.

Cheers PDG it's not really commercial more a hobby free time for projects

 

[mike 109444]

If some of what you need to blast is for removing rust, then consider some of the many chemical methods that go on working while you get on with something else. Search forum for "rust removal" lots of ways !

 

[rtbcomp]

A big nozzle using coarse grit will use less air than the same nozzle using fine grit.

 

[brightspark]

I've just thought about it - I don't think the nozzle makes much difference to air usage on my syphon gun - it only affects the media pickup.

the blast nozzle will be less than 1/8 of an inch on a siphon gun

 

[rtbcomp]

On a syphon gun there are two nozzles, the air nozzle and the grit nozzle, air exits the air nozzle over a venturi and sucks media into the gun, the mixture of grit and air is expelled through the grit nozzle, thus air usage is determined by the size of the air nozzle.

On a pot the air and grit are mixed at the base of the pot and the mixture is forced up the pipe and through the nozzle.