Pressure sandblaster from propane tank

[Joe from N.Y.]

UPDATE 01/18/12

Upon further reflection, and several friendly warnings from those more experienced in such things than me, i am removing all the original text from this post and warning others what a stupid idea this is, and it should not be undertaken if you value anyone's life. After reading the thread linked further down this thread regarding the danger of pressure vessel welding, i completely agree that it was way above my ability, and added to that fact, it was a rusty discarded tank to begin with. I wanted a project and I had the tank laying around, but I did not realize what a dangerous idea it was.

To the several Brothers who objected to this project, especially tanglediver and Bearston, thank you for your concern and advice.

I will concur with those advising not try this dangerous stupid project.

[Joe from N.Y.]

[Joe from N.Y.]

Finished and painted:

[TJS]

Cool idea. I do not really understand the large top fitting though. Is this just a cap to fill it (what size is that NPT). Also why do you "T" it off and run a hose to the bottom "T". Is this how they are supposed to be. Is this just to induce air into the sand at the bottom "T". Also what is your safety blow-off set at. I might make one.
T.J.

[Joe from N.Y.]

Cool idea. I do not really understand the large top fitting though. Is this just a cap to fill it (what size is that NPT).

Yeah, that is 2 inch pipe cut off for a filler hole. You use a funnel and pour your media in then cap it tight, using a piece of an old innertube as a gasket.

Also why do you "T" it off and run a hose to the bottom "T". Is this how they are supposed to be. Is this just to induce air into the sand at the bottom "T".

The air enters the tank above the media (sand) and forces it down and out the bottom, while at the same time, an alternate path of air is routed down outside the tank and then joins the flowing sand at the "T" fitting. This keeps the sand moving with required pressure.

Also what is your safety blow-off set at. I might make one.

I put a 125 PSI safety valve for a safety blow off. My compressor just about reaches that pressure, and i use the plastic regulator to keep below 100 PSI. Since the photos, i replaced the washing machine water hoses with real hydraulic hoses i got from the Northern Hydraulics catalog. The blaster works excellent. I used to have a siphon type toy from Sears, It always clogged up and generally sucked. But this thing just blasts away rust and paint at an unbelievable rate. I use Black Beauty Abrasive, and i don't choke on silica dust anymore. This is one of the most useful projects i have built.

[m.k.swelding]

I have used a propane tank before to make a tire bomb to inflate truck tires

[MMW]

To add to the OP's explaination -- the valve under the tank is only opened part way to regulate the amount of sand that comes out. If opened all the way you usually get way to much sand. The valve on the end of the hose (where the sand comes out to blast) should be opened all the way or it will have a short life as the sand will wear it away quickly if used to regulate flow by leaving it part way opened.

[rodknocker]

nice looking blaster but if you you use it a lot it will wear through the t fitting on the bottom, on commercial unit the t is actually a 4 way fitting with a plug in the bottom so there is more material there to wear.

[ricau]

Nice project Jonh and it's a good size for portable and small job. A use to be a sandblaster my self for 5 ears, 7 ears ago whit industriel big stuff!! Your kit is very cool , and y see that your a welder debutant seeing your welds
Ricau

[Joe from N.Y.]

To add to the OP's explaination -- the valve under the tank is only opened part way to regulate the amount of sand that comes out. If opened all the way you usually get way to much sand. ...

Thanks for clarifying that point. You are completely right. if opened up too much, the blasting nozzle loads up with media and you get a real sh1t storm out of the nozzle when you hold the deadman lever, and a mess to clean up in the driveway.