Sandblasting: need some help here...

[KurtHuhn]

You asked!

[timothy thorpe]

lol...funny bruce! i learned pretty fast with blasting..however i seem to alter the shape alittle. i use glass beads. it is a alot to get set up...now i am learning about the vac that collects the media..its needs a bag etc

[archaggelosmichail]

What is the grit that you're using?

[archaggelosmichail]

I've be thinking about buying sandblast machinery since March.

I found someone who sell an 4hp compresor and I think that with a 220lt blasting cabinet will be ok, or not?Is that 1hp of extra power have so much impact on the final result?

[KurtHuhn]

I've be thinking about buying sandblast machinery since March.

I found someone who sell an 4hp compresor and I think that with a 220lt blasting cabinet will be ok, or not?Is that 1hp of extra power have so much impact on the final result?

The answer is - "Maybe".

There's a lot of factors to account for:
- airflow in CFM
- max CFM at high pressure
- media type and size
- tank size
- gun type
- size of nozzle and CFM rating of jet

Can you blast pipes with a 4HP compressor attached to a gun configured for 15CFM? Sure. It's not comfortable though, and it will take a long time, and you might have to get creative with your media, and you might never get the result you REALLY want - but it can be done.

The HP ratings are only tangental to the capabilities of the compressor. They can give a good idea of starting point, but you really want to concern yourself with CFM and CFM at max pressure.

[archaggelosmichail]

Thanks for answering.

So what cmf and cmf at max pressure should I want it to be? the one that I'm looking has 145psi(10 bar) presure and 20cmf(550ltr per min) capacity and 300ltr tank size.

[RadDavis]

Thanks for answering.

So what cmf and cmf at max pressure should I want it to be? the one that I'm looking has 145psi(10 bar) presure and 20cmf(550ltr per min) capacity and 300ltr tank size.

You need at least 90psi and many times more for the initial blast. You could get by with around 80, I suppose, but it will take much longer. Also you need as high CFM as you can afford. Usually, the higher the CFM rating, the higher the HP.

Also, you want the gun to be the limiting factor in how much air you can move, so if your gun is rated at 18 CFM, you want your compressor to be able to deliver at least that at blasting (80-90) psi.

[Sebastian Heck]

Tagging on to this old thread... As I just got a nice used sandblasting rig, I am wondering if there are general suggestions as to nozzle diameter?

[Sasquatch]

I think you'll find that the answer is "it depends". Depends on media, pressure, what gun you have, every variable. I think in generall the media and pressure have a bigger result than the nozzle. I have a janky rig with the consumable tips, and I simply start with a worn one that is probably 8 mm or so and finish with a newer one (at 3 or 4 mm I guess). But the truth is, some briar blasts very easy and well, and some doesn't blast worth beans, and it's not really about the nozzle in that case.

[Sebastian Heck]

Thanks Sasquatch!