In addition to what Oro has given you (pretty good advice), here’s some of my experience/thoughts on blasting:
First and foremost, get yourself a good respirator.
Then, ideally, a large cabinet, large compressor and exhaust/filtration/collection unit.
Me? I went with a small, leaky, bench top cabinet, barely adequate compressor (I used a
small Harbor Freight compressor for years and a barely larger Sears unit now) and no exhaust/filter/collection system.
I had read that most of the bench top cabinets
leak to some degree; mine was no exception, but at least I knew it would need some work before use (mostly requiring RTV sealer). It also does not have a light. I would get one with the light built in if I do it again. The unit is from Harbor Freight. I would list the SKU , but it was discontinued (here's what it
looks like, price was near $120).
Something similar to this might be my next project:
http://blog.makezine.com/archive/2008/08/homemade_grit_blasting_ca.html
The compressor required depends upon the air consumption of the blast gun. The cabinet I chose was a good match for my small compressor on paper, but I need to let it "catch up" (build pressure) in real use. Bigger is better here.
Blast medium: 70 or 80 grit aluminum oxide from Harbor Freight is a good start; as is their 80 grit glass bead. Just like sandpaper, the higher the number the finer the grit.
Silica is very bad for your lungs. You will almost always see admonitions against using it for blasting. It works (60 grit) and is cheap for outdoors use, but you use it at your own peril.
Now, all that said, here is what I what I currently use:
I have my cabinet mounted on a small table (cart would be better) so I can move it outdoors for use. I still use it inside, but prefer outdoors because of the leakage. I mainly use the cabinet for glass bead.
The compressor is still playing "catch up"
I "sand blast" out in the yard using a hand held blast gun (about $15 at Harbor Freight; it does not have SKU on it or show up on the HF website searching for "blast guns" It is siphon feed with a white plastic container under the gun).
ALWAYS WEAR YOUR RESPIRATOR when using it. It's a good idea to use the respirator when using the cabinet as well.
The guns works better for me than the cabinet, but consider media loss with the gun at 100%. Then, if you blast into 55 gallon trash can you will reclaim some media and not be disappointed in the amount reclaimed.
It's a messy; as in you'll get quite a bit on yourself.
Wear the respirator.
Don't mix and match used media. If you blasted carbon steel parts, only use that media to blast carbon steel and so forth. You don't want tiny particles of carbon steel (rust magnets) embedded in your aluminum or stainless steel parts.
Blasting results can be manipulated by blasting from various distances and/or changing air pressure. You can also mask off areas to produce different surfaces; I like to bead blast stainless guns, but sand blast the top rib/sight plane.
I use the cabinet/compressor a lot; prepping surfaces for paint, cleaning rust off of auto parts/old tools, cleaning up welds, blowing dust/debris out of the shop, etc. It also brings a whole line of air tools into play; love my air ratchet. It's a boon for DIY parkerizing (easy to do) as well.
Bead blasted:
Sand blasted sight rib (more photos of the bead blasted Model 60
here):
Sand blasted and pakerizied:
http://gbrannon.bizhat.com/1911.htm
Regards,
Greg
