[AT] Sandblasting

[Dennis Johnson]

I am making a holder for some 4' X 8' banners to advertise various church events. Will mount in ground so it can be seen from the road. I got some old 1 1/2" pipe and welded it up. Then I tried to blast the rust and scale off of the pipe so I could prime and paint it.
I had an old suction type blaster, that seemed to work fair for a few previous projects. It started working fine for this, and then quit working. I replaced the blast gun, and it blasted about 6" of pipe and quit.
I got frustrated and went out and got a 40 pound pressure blaster from Harbor freight, plus another air compressor. I have one compressor that is about 6  or 7 CFM with a 30 gallon tank. Found another "free" compressor that is a real small compressor guessing about 2 CFM but was mounted on a 60 gallons tank. Found Harbor has a compressor sale with one that was $179 after $319 off (something my wife can understand) so I got that. It is 4 or 5 CFM with a 20 gallons tank. Got all of these connected together and have a small discharge manifold I put on my shop wall.
Got the blaster assembled, put some sand in it, and it did terrible, barely blasting. Finally figured out the sand I had was contaminated with small rocks that plugged things. (Probably also the reason the suction blaster was not working). Went and got some insect screen, and used it as a sieve to screen out the rocks from the sand. Put in the the fresh sieved sand, and the blaster started working like it was supposed to. Worked great for a bit, and then blew of blast hose. Short trip to parts store for new clamps, and then it was working great again. Guessing a 50 pound bag of play sand will blast 10 to 12 feet of pipe.
After I get this blasted I need to fix a few things on the blaster like disassemble and rotate the handles that came installed backwards. 
Anyway I am happy that I now have a blaster that works great, plus enough compressors and tanks to blast about 5 or 6 foot of pipe at one time, and then shut down the blaster and prime that section while the compressors catch up.
Grit would be better, but this sign holder is about 10' high, with two sides that are about 10' long spaced at 90 degrees, so the outside pipes are about 16 foot apart. Point is that it is too big to blast where I can save and recycle the grit and sand is cheaper.
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