[modas]

Hi Guys -

I've got a question on how a pressure pot sandblaster operates. I understand that the pressure inside the tank is what pushes the sand out of the gun onto the work piece.

All the pressure style sandblasters rate at 65 PSI and up. Would they still function if they were dialed below the 65 PSI? I would think that they would operate at any pressure above atmospheric (15 PSI).

Am I correct in this assumption? I was looking at this blaster from eastwood. If I can't dial it down and have it work properly, I'll have to keep looking

http://www.eastwoodco.com/shopping/p...&keyword=12064

Thanks for the help!

Joe

[oldred]

Modas, Basically the idea behind a pressure blaster is increased velocity. The pressure in the feed line and the tank is equal until the valve is opened then the air passing the metering valve will create a venturi effect which will cause a slight pressure drop between the line and the tank allowing the sand(media) to drop into the air stream without being blown back into the tank. So it operates on a pressure deferential and gravity and does not depend on high tank pressure to feed the sand (media).

[Bee4Me]

That's a first. E'wood is cheaper than Harbor.

Couple of things with those. You will need to "throttle" the bottom product feed valve way down as IF you run it WFO it will drain the media in no time wasting it.
You will need a DRY air supply and a separator AT the blaster helps.
Once enough moisture get's into the tank it's a PITA to use,so it's dump it out and dry it out.
It has a nice dead man nozzle which Harbors only comes with a cheap ball valve all though they sell the same nozzle, which is the one I use,just some more money for a decent nozzle.

[shine]

my pot is quite a bit larger than that but works on the same principle. old red is right. my pot has to maintain 65 lbs min. if the pressure inside the pot is less than the work line the media simply will not fall out into the flow. it takes a large comp to run one. mine is 185 cfm. you will be blasting at around 30 lbs with a 5 hp. it will drive you nuts as it will not run long without losing flow. good luck.

[oldred]

Modas, Another point about the nozzle and that is if you are using a small compressor(12-14 CFM, 5 HP is small when talking sandblasters) then get the small nozzle size of 3/32". This may be too small for some media but something like a 5/32" nozzle will drain a compressor that size almost instantly!