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Bryce.R
06-24-2012, 04:28 AM
Ok so heres the issue :) looking for a new sandblaster over the next week :) looking for something in the local area. i only have a 320 lpm air compressor so size is obviously limited. Want something that will still blast a decent sized area.
Heres what iv been looking at so far...
Which is the ones I should be getting? :confused:
What do you have?
http://www.amanstoyshop.com.au/ProductDetails.aspx?productID=1304
http://www.amanstoyshop.com.au/ProductDetails.aspx?productID=160
http://www.amanstoyshop.com.au/ProductDetails.aspx?productID=161

hardtail
06-24-2012, 05:24 AM
I would go with the larger pressure pot, they are far more effective than siphon........

Bryce.R
06-24-2012, 06:10 AM
Will the bigger one of the 2 pressure pots require more air to drive it?

hardtail
06-24-2012, 08:01 AM
I doubt it, they probably both come with interchangeable orifices for flow......

metalmagpie
06-24-2012, 03:08 PM
I have messed around a fair amount with sandblasting. I would agree with the earlier suggestion to avoid a siphon pot.

You are only going to be able to blast for a short time until your compressor won't keep up. I find with a 20 lb. pressure pot my 18 cfm (514 lpm) can just barely cope. My recommendation is to rent a large trailer mounted compressor for the blast day.

Breathing is a big issue. I use an air hood. If you don't want to do that, at the very least invest in a top quality cartridge mask and some spare cartridges. Paper dust masks are not sufficient.

Clogging is a huge issue. For a small pot I recommend a 1/8" (3mm) orifice and 120 grit sand. No coarser! And make a sifter from a wood frame and some stapled on window screen. Sift your media before you blast, and especially after you blast if you use it.

Sandblasting is awfully messy. Best is to do it outside in a fully enclosed tent-like canopy. The side benefit is that you will retain the sand and be able to sweep it up, strain it, and reuse it.

There are alternatives to sandblasting. You can remove grease and old paint by boiling your parts in a solution of TSP or just powdered dishwashing detergent. Rust can be removed by electrolytic derusting or by soaking in a bath of EvapoRust warmed to at least 70F. Stubborn chunks can be removed mechanically with wire brushes on angle grinders (large) or small wire brushes on die grinders (small) or needle guns.

I only use sandblasting as a last resort. In actual fact, I have only sandblasted once in the last 15 years. To do that I bought a used pressure pot and used air hood, then resold them afterwards.

All that being said, there is nothing like sandblasting to prepare a surface for paint.

Good luck!

metalmagpie
Seattle, Washington, USA

Bryce.R
06-25-2012, 07:38 AM
Second opinion here :) will a bigger pot need more air?

garagemark
06-25-2012, 08:04 AM
The pot itself should have little effect on overall air consumption. Air usage will depend more on the orifice size at the head. Once the pot is pressurized, it simply acts as a force feed for material, kind of like pushing the material out of the chamber.

But by all means a pressure pot will do a hellufa lot more and better work than a siphon feed. Been there, made that mistake once. :mad:

digger_doug
06-25-2012, 01:32 PM
The pot itself should have little effect on overall air consumption. Air usage will depend more on the orifice size at the head. Once the pot is pressurized, it simply acts as a force feed for material, kind of like pushing the material out of the chamber.

But by all means a pressure pot will do a hellufa lot more and better work than a siphon feed. Been there, made that mistake once. :mad:

Carefull here.

Yes, it is a true statement.

But as you reduce the size of the nozzle (for your limited air supply)
you need to also reduce the size of your sand hose.

3-to-1 is the rough ratio I use for sand hose dia.-to-nozzle size.

Get too big, and the sand falls out of suspension, and will surge and
plug, causing problems.

Finding small bore (1/2" I.D.) sand hose is hard,I have used standard
rubber air hose for the sand hose, with no problems.

chipmaker4130
06-25-2012, 06:14 PM
You can use automotive 'low side' refrigeration hose with an inside diameter near .5". It lasts for years. I also recommend a boron-carbide nozzle. I bought one from a supply house and modified it to work with my unit. I've blasted nearly a hundred hours with very hard abrasive and still can't measure any wear on the orifice. The ceramic nozzles wear out in minutes with hard media. The main thing with a bigger pot is that you don't have to stop and refill it constantly, although it will be heavier and more difficult to move around.

oldtiffie
06-25-2012, 10:35 PM
I have messed around a fair amount with sandblasting. I would agree with the earlier suggestion to avoid a siphon pot.

You are only going to be able to blast for a short time until your compressor won't keep up. I find with a 20 lb. pressure pot my 18 cfm (514 lpm) can just barely cope. My recommendation is to rent a large trailer mounted compressor for the blast day.

Breathing is a big issue. I use an air hood. If you don't want to do that, at the very least invest in a top quality cartridge mask and some spare cartridges. Paper dust masks are not sufficient.

Clogging is a huge issue. For a small pot I recommend a 1/8" (3mm) orifice and 120 grit sand. No coarser! And make a sifter from a wood frame and some stapled on window screen. Sift your media before you blast, and especially after you blast if you use it.

Sandblasting is awfully messy. Best is to do it outside in a fully enclosed tent-like canopy. The side benefit is that you will retain the sand and be able to sweep it up, strain it, and reuse it.

There are alternatives to sandblasting. You can remove grease and old paint by boiling your parts in a solution of TSP or just powdered dishwashing detergent. Rust can be removed by electrolytic derusting or by soaking in a bath of EvapoRust warmed to at least 70F. Stubborn chunks can be removed mechanically with wire brushes on angle grinders (large) or small wire brushes on die grinders (small) or needle guns.

I only use sandblasting as a last resort. In actual fact, I have only sandblasted once in the last 15 years. To do that I bought a used pressure pot and used air hood, then resold them afterwards.

All that being said, there is nothing like sandblasting to prepare a surface for paint.

Good luck!

metalmagpie
Seattle, Washington, USA

+1

Why not get a quote from a professional sand-blaster for him to do on his site? All the OP has to do is deliver it to the site, get it done, pay for it and then get it home.

If there are close-by neighbours they might not be too happy with dust and noise from a diesel-driven compressor.

Same might apply to a lesser extent with spray-painting - its surprising how far and what damage "over-spray" can do and how far it can go with the right weather conditions.

Might be easier to get the pro spray-painter to paint the primer and top coat/s as well.

chipmaker4130
06-26-2012, 12:50 AM
Why not get a quote from a professional sand-blaster for him to do on his site?

Because that might take days to get a 30 minute job done, and because it is expensive compared to doing it yourself. A sandblaster is a very handy piece of equipment, and for smaller jobs it isn't all that messy.

oldtiffie
06-26-2012, 04:36 AM
I have a friend who has a large industrial sand-blast and spray establishment.

I'm sure that he'd have it done in a day or so - and not all that expensive either what with plant, paint, filtered hood and no sand (has to be garnet due to OHS problems and silicosis etc.) to buy or clean up, and having to store the compressor and blaster - and any sand, paint etc. etc.

For a biggish compressor electric power may be a consideration.

From my point of view, I just want the job done - properly and off-site - without the expense of the kit and my likelihood of only needing once every 2>5 years - perhaps less frequently.