Anyone else built their own sandblaster?

[mhorowit]

I lent my Clarke sandblaster to a friend last year, leaving me without one, so I built one using a freon container. Got the plans off the Inet. It puts pressure in the tank (around 7-10 psi) and and the same pressure shoves the aggregate to the gun. At the gun, the aggregate mixes with a 90psi airstream and out the nozzle.

Has anyone else built or worked with a blaster like this and how do I figure the appropriate pressure in the tank? Is it simply "try, change, try" until I find a mix that works or is there a better approach? - Mike

[Ray36048]

Re: Anyone else built their own sandblaster?

You know the cheap ones that you just stick the hose in a bucket of sand actually work very well.

The only thing you must do is strain the sand. Play sand you buy at Home Depot has many small rocks that can plug up any sand blaster.

[bashibazouk]

Re: Anyone else built their own sandblaster?

Yup. Built one out of a 100# LP tank. It's a monster. The amount of pressure in the tank doesn't seem to matter too much with mine, as long as there is SOME pressure and the sand is dry and uniform in size. The sequence of valve opening on mine is also important-- First the air through the hose to the deadman valve and THEN the media valve. If the hose gets filled with sand/soda first, it surges like crazy until it clears out, but once that's done, the rust/paint/skin/grass doesn't stand a chance.

You can make yourself a riddle to screen the sand with some heavy duty window screen. Make a four-sided box (no top or bottom) and fasten the screen to the bottom. Not sure what grit that ends up being, but it works pretty well in the "Master Blaster." Fill-shake-shake-shake-shake-dump. Works great/lasts a long time.

Josh

[mhorowit]

Re: Anyone else built their own sandblaster?

Yup. Built one out of a 100# LP tank. It's a monster. The amount of pressure in the tank doesn't seem to matter too much with mine, as long as there is SOME pressure and the sand is dry and uniform in size. The sequence of valve opening on mine is also important-- First the air through the hose to the deadman valve and THEN the media valve. If the hose gets filled with sand/soda first, it surges like crazy until it clears out, but once that's done, the rust/paint/skin/grass doesn't stand a chance.

OK - Media valve at bottom closed, add tank pressure; start high pressure thru gun; begin opening the media valve. I'll try that sequence this PM. I built Len's coalescing filter to dry the air so that should help.

Do you open the media valve fully or is there a balance between the media flow and the hose pressure?

What gun are you using?

With the Clarke SB there is a nozzle with a deadman closure device which I had been using as an on/off switch; that wore the rubber pad/gasket off in a hurry. Turns out that really is intended as a deadman valve; once you open the media valve it's supposed to keep spraying until the media valve is closed, so I"ll tape the gun open and find some way to catch the media when I"m not holding the gun but the blaster is running.

You can make yourself a riddle to screen the sand with some heavy duty window screen. Make a four-sided box (no top or bottom) and fasten the screen to the bottom. Not sure what grit that ends up being, but it works pretty well in the "Master Blaster." Fill-shake-shake-shake-shake-dump. Works great/lasts a long time.

At the moment I'm using a kitchen sieve. Not high volume but I'm not in a rush at this stage.

Mike

[bashibazouk]

Re: Anyone else built their own sandblaster?

The degree to which you open the media valve on the bottom depends on what you're using to blast (ie. sand, beads, shells, soda, etc.), how big the chunks are, and how aggressively you need to remove stuff. With finer abrasives, my blaster surges with the valve full open-- less pressure in the tank doesn't seem to fix it because the media tends to clog up if I reduce pressure.

Yes, the valve at the business end of the hose needs to be full open or it'll wear out whatever you've got in a hurry. I'm using a 1/2" ball valve with a ceramic orifice mated to an adapter. The ball valves are pretty cheap (compared to blaster-specific parts).

Good on ya for building a dehumifier. I ended up buying a Hankison membrane unit off eBay. It was pricey, but I am really happy with it. No maintenance-no conumables-no fuss-no muss. Just dry air and lots of it. Any water in the mix will make your life miserable-- as if suiting up for blasting in the summertime wasn't bad enough. Speaking of that-- please do use a good respirator and eye protection. Silicosis from blasted sand is no joking matter. A little care and expense now will save your lungs for a long life of flying your Taylorcraft.

Josh

[Hank Jarrett]

Re: Anyone else built their own sandblaster?

I built my own years ago and used a siphon gun. The gun works fine. The box is HUGE and I made it from 1/2" plywood. I have used the heck out of it and the inner ply of the wood is blasted off in some areas (it will take decades to wear through). The "floor" is screen wire (inside the box) to hold the parts and allow the sand to fall through (DON'T try to blast something on a solid surface, you will never see it in the cloud of reflected sand and dust).
Don't EVER use play sand, construction sand or (God forbid) beach sand (it's full of salt). Buy your sand from a blasting supplier. You can also use blasting media, black media, walnut shell or plastic media (never had much luck with soda but it is good for aluminum).
I have even set it up to blast my wing struts with holes in the ends so I can feed the struts through from one end (rubber inner tube to seal the holes).
BE prepared for the rush of folks with "just a small part" that needs blasting. If it has lead paint on it (or other stuff like Cad plating) it can contaminate your blast media. If you get spot checked by the EPA (and you COULD!) and they find contamination you will find yourself paying a hefty fee for waste disposal. It is EXPENSIVE to dispose of a drum of lead contaminated sand (you get the joy of paying for disposal of a 55 gal. drum with 5# of sand in it too).
I had to finally start refusing to blast their stuff unless they brought their own bag of sand, I cleaned the machine before and after and they took away all of the waste. Cut back a lot on the "just a couple of parts" people. NEVER do old lawn furniture or mower parts!
Hank

I would be really careful using a gas bottle. a little too much pressure and the bottle could burst (if I have the right mental picture). A burst propane bottle would probably blow your garage door off! Don't underestimate the power of compressed air.

[mhorowit]

Re: Anyone else built their own sandblaster?

Yes, the valve at the business end of the hose needs to be full open or it'll wear out whatever you've got in a hurry. I'm using a 1/2" ball valve with a ceramic orifice mated to an adapter. The ball valves are pretty cheap (compared to blaster-specific parts).

Can you post a picture or a drawing? I'm trying to visualize what you've done and how the two hoses attach - Mike

[mhorowit]

Re: Anyone else built their own sandblaster?

Don't EVER use play sand, construction sand or (God forbid) beach sand (it's full of salt). Buy your sand from a blasting supplier.

Hello Hank - why not sieved play sand?

I would be really careful using a gas bottle. a little too much pressure and the bottle could burst (if I have the right mental picture). A burst propane bottle would probably blow your garage door off! Don't underestimate the power of compressed air.

Yes indeedy. Regulator set to 7psi.

Mike

[Dick Smith]

Re: Anyone else built their own sandblaster?

Here is a link to a few ideas. Be very careful with anything related to pressure...it can kill or maim you.

http://images.google.com/images?q=homemade%20sandblaster&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&sa=N&hl=en&tab=wi

Dick

[mhorowit]

Re: Anyone else built their own sandblaster?

You know the cheap ones that you just stick the hose in a bucket of sand actually work very well.

RAy - so I can get an idea of what it can do, how have you used yours? - Mike

[Ray36048]

Re: Anyone else built their own sandblaster?

Just about everything. Steel parts from the T-Craft a whole fuse from a glider. Buy one, they are cheap. The pipe that goes into the sand is a double wall unit. I used radiator hose inplace of the hose that came with the blaster.

You ust stain the sand first. As I said, you will find many many rocks.

These can be bought at Home Depot, Lowes and even Wal-Mart.

http://www.chpower.com/webapp/wcs/stores/servlet/chPrd5_10051_10001_86237_-1_search

[bashibazouk]

Re: Anyone else built their own sandblaster?

Can you post a picture or a drawing? I'm trying to visualize what you've done and how the two hoses attach - Mike

I'll take a picture when I get home, but this is my best shot at drawing on the laptop. One hose to the valve-- air and sand mix at the bottom of the tank.

Yes, I agree that things under pressure can explode and do regularly. Keep the pressure in the tank low with a regulator and have a gage on it to monitor. The opening at the top is a 4" steel pipe with a bridge welded across it and a nut welded to that. The T-handle is on a piece of threaded rod with a flat plate at the bottom. You screw open the valve and dump in your grit, close the valve and pressurize the works. The seal is a piece of inner tube and it leaks like crazy. Sure, it could still explode if everything was plugged up and the seal actually sealed perfectly. As my Dear Mother always said-- "Just be careful-- you might burn yourself."

The scariest part for me was cutting the empty 100# propane tank. I unscrewed the valve off the top and filled it with water, then cut it with a 1/8 abrasive wheel. Still made me nervous!!



Rats. Spelling errors and there was supposed to be an arrow from the ball valve to the text!

I buy 80# bags of "washed play sand" from a local farm supply place. To be honest I haven't tested it for salt content, but I'd like to think that "washing" takes care of some of that. I'd shy away from beach sand, too, obviously. I know that the "real" blasting sand is screened already. Maybe there are guarantees as to the amount of salt that's in it.

Hank, who'd you piss off at the EPA? Whatever you do, please keep them busy there so they don't come to North Carolina!! I think if they ever got to my neighborhood, they'd be so upset about the hog waste lagoons that they'd leave the hobbyist blasters and solvent-cleaners alone for a bit!

Josh

[bashibazouk]

Re: Anyone else built their own sandblaster?

Oh yeah, and don't forget about your #1 Source for Cheap Chinese Crap, Harbor Freight!! (I use that phrase lovingly, of course-- I've got more of their tools than I'd like to admit).

They've got various blasters ranging from $30 to $300 and more for the cabinet ones. Also, if you have a store close to you, they sell abrasives in the 50# box. Their price on glass beads is pretty good. I've used the black clinker abrasive and it works great, but removes metal so I'd only use it on tractors and the like.

Here's a link to the first blaster page.

Josh

[mhorowit]

Re: Anyone else built their own sandblaster?

Just about everything. Steel parts from the T-Craft a whole fuse from a glider. Buy one, they are cheap. The pipe that goes into the sand is a double wall unit. I used radiator hose inplace of the hose that came with the blaster.

Ray - I went to the shed, reconfigured the gun to act like a siphon, ran the PSI to 90 and took some heavy rust off some scrap. Nice.

What pressure do you use? - Mike

[Ray36048]

Re: Anyone else built their own sandblaster?

On steel, as much as I can get.