I know some of you do sandcarving and use your lasers to cut masks. I am looking into adding this to my business as well, and am looking for a low cost (sub $1000) blast cabinet setup. Is there such a beast? My preliminary searches seem to turn up lots of $200 - $300 systems which I assume will not be satisfactory long term, then the prices seem to skyrocket to above $2000. Would anyone be so kind as to provide specific names and model numbers of setups they are using? Eternally grateful.
I think a lot would depend upon the size of the unit you need, i.e., how large is the substrate you want to etch/blast. You can purchase excellent blast cabinets from TP Tools out of Ohio.
Their model 960 is virtually an industry standard for the automotive restorer industry (around $1100), though they also have smaller units (940 and 950) with correspondingly lower prices (I think the 940 is around $700 and will take something up to 34″ long - the 960 is either 46 or 48″ long inside).
Don’t forget to factor in the cost of a GOOD dust collector - and not something you would buy from Harbor Freight or Grizzly as they literally would get eaten by the abrasives! You need a collector specifically designed for abrasive blasting cabinets. These units can run from several hundred to several thousand dollars by themselves. You also want to consider the compressor that you will be using, i.e., can it continuously supply the blasting gun. Then there is the abrasive itself - tailor it to the task at hand - and NEVER, NEVER, EVER use real silica sand!!!!!!!!!
I can list what is key to a good setup. You can decide if you need to cut corners.
You need an air compressor. You need about 7 scfm of air at 90 PSI. This is either a big 110v compressor or a small 220v compressor. Big tanks are nice. The advantage of a bigger compressor is it runs less often.
You need a blasting pot. The cheap harbor freight ones work, but if you can find a cheap pot with more of a funnel shape, you’d be better off.
You need a foot switch. Yes, you really NEED it. They run about $100.
Blasting cabinet. If you get one too small, you will have a sandstorm when you try to blast. Look for a cabinet with good lighting or add your own. You only need sleeves to blast, big rubber gloves are too clumsy. Its also ideal if the cabinet will drain right into a bucket.
Dust collector. You need something to keep the air clean. It can be as simple as a shop vac with a hepa filter and a separator bucket.
Grit. I like 90 grit silica carbide. It breaks down finer as you use, so you end up with a mix of 90-dust.
Question in regards to the size of the nozzle opening. How large do you recommend?
I’m very happy with the 3/32″ Carbide Nozzle my rayzist cabinet came with. Ceramic tips wear out quickly, so get a tip with a large opening so it won’t be as much of a shock when you go back to a new top and the new tips won’t wear as fast. The carbide tips wear MUCH slower than the ceramic ones. Rayzist sells carbide tips, but you can probably find somewhere cheaper.
The vast majority of the work we do is just a quick surface frosting using blue masking tape as a resist. The rest of the time I use the rayzist resist. I’m still looking to try the right mylar.
I probably should mention my outside setup because it pretty cheap. Harbour freight sells a blasting gun for $30. It holds a few cups of grit which it gravity feeds into the gun. We use a home depot shop vac for a dust collector with a hepa filter. At the end of the vac, we got brush attachment for the vac and drilled a hole in the back of it to put the tip of the blasting gun through. Then we simply turn on the vac and put the brush against the piece to be blasted and pull the trigger. If you’re careful, all the grit goes up the hose, but its common for a little bit to fall out when your tired. The setup really needs a grit trap. Because its a gravity feed blaster, you compressor needs to be pretty good. To be portable, you’de want as big of a compressor as possible which runs on 110 and is transportable. Home depot has a 60 gallon standup compressor for about $400 that’s pretty nice. http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=45998
Thank you all very much to those who responded to my query regarding blast cabinet specs. The info offered did answer many of my questions, however I do have one more. Is anyone using a siphon feed for production work successfully? My understanding is that pressure feed units allow for blasting at a lower pressure, reducing the likelihood of resist blow-off. Sounds nice, but is it worth the extra (considerable) expense? I don’t mind spending the extra money if needed, however, I don’t want to scrimp and just end up buying a unit that will ruin product and cause endless frustration. Thanks to all again.
The air needs for a syphon feed is subtantually more than a pressure pot, so it takes quite a compressor to be able to suply that much air and like you said, that much air tends to blow off resists. Syphon feeds work best when your sandblasting the broadside of a boat where the grit can’t be recycles due to what its spraying and the air action is looked on as a cleaning action. You need something more delicate for the work you want to do.
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=9588
The 40 pound pressure pot at harbor frieght is under $80. I own one of these and also a 20# model. The only thing I don’t like about them is the feed tends to clog and i need to kick the can to get the grit flowing again.
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=34202
I also use a gun model from harbor freight. at 7scfm at 90 psi, its an air hog! Its great to use. It’s a lot like using a paint spray gun.
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=45998
if your going to buy a pressure pot, be sure search the archive of the sandcarvers group or ask there again. I seem to recall a model similar in price to the harbor fright model with a better designed feed. Basically the bottom of the harbor fright model is nearly flat where a good design would make it funnel shaped.
What’s nice about harbor freight is that they have stores in most major cities where you can pick up the heavy products and avoid shipping. Unfortunately, the selection they have in stores is limited.
Thanks much. I think I have enough of an understanding that I can start to shop around. I do have a Harbor freight not too far away so I’ll check them out.