Sandblasting Wisdom

[Joe Hubbard]

I'll throw in my two cents (about what it's worth too) I started with a sandblaster because it was lots cheaper than the laser but really wanted to do photos on glass and stone. With practice you can do it with photo resist and the sandblaster but when I bought the laser I stopped trying to sandblast photos. There is a huge quality difference though - even though the laser is faster, cleaner and easier the sandblasted photos are in my opinion nicer. I have a pass through blast cabinet and mostly use it now for wood signs - so my grit/pressure recommendations. For wood (I usually glue up cedar 2x6 or 2x10's with biscuts - use outdoor glue) I blast at about 80psi using 60 grit aluminum oxide. It's important to screen the medium each time you recycle because the little wood fibers plug up the hose and nozzel. I use a 1/8" boron nozzel (much more expensive but it lasts a lot longer) - start with 1/8" because it will soon be 3/16". For wood signs I use a plotter to cut hartco 530 resist (I've had trouble with blow off with vinyl). For glass & granite - especially for fine detail I clean the cabinet really well (don't want to mix grits) and use 220 silicon carbide (again more expensive but lasts longer) and from 25 - 40 psi depending on the resist material. Laser tape works well but will blast off at higher pressures. Photo resist works great but is very expensive and a little troublesome to wash out (develop) apply and generally work with. When working with higher pressures plan on replacing hose and fittings from time to time as the grit eats through them. Also plan on replacing glass view ports as the grit at higher pressures bounces off the wood and pits the glass. I've found that tempered glass (anealed) stand up slightly better. I guess the bottom line is that the sandblaster and the laser are really the odd couple that really are meant for each other - as tools they compliment each other and both allow very creative expression. There are sandblasting only forums as well that get really detailed especially about glass items. Joe

[Bill Cunningham]

I installed a blast cabinet in the shop last week.. This was a cheap cabinet , a `put it together yourself` job (on sale $150.00 complete with gloves,gun, light etc.. couldnt pass it up!!) .. Had no idea what to expect, got a bag of 100 grit (free) dumped it in, stuck the vent hose out the window, fired her up, and quickly discovered sand leaking out of most of the corners etc.. opened the dump port and emptied it out into a 5 gal pail and Out came the silicone caulking gun.. spent the next hour caulking the inside and outside of every joint to stem the tide of leaking sand.. The next day: dumped the sand back in and fired it up.. a couple of minor sand leaks (plug em later)... 100 grit seems really fine, 220 must be like flour? I found the 100 grit to do a good job `frosting` all those reject and set-up shotglasses just to make em look more interesting rather than etched up errors.. The learning curve has started... Now i just got to decide what I want to do with it..