10 Questions You Should to Know about Blasting Glass Beads

Hey Dawgs,
I went and bought a sandblast cabinet today and when I started looking at all the choices of media at Harbor Freight, I was amazed at how much...they didn't have! Like most things, they have a poor selection. I know that the equipment they sell is basically "get-by" equipment until I can afford better, that is unless it turns out to work exceptionally well. Anyway, my choices were 70 grit AO, medium screen glass, walnut shells that didn't have a grit size that I saw, there may have been a couple more that didn't make the list of important enough to remember. I want to finish my "using knives" with a glass beaded finish, I want it to have that frosty/dullish look. Will medium glass beads do it? Are there better or easier media to use for doing this? I know I can Google this, but I was wanting to know what you all use. You know, get the expert instructions from the experts! Or at least someone who has experience using different types of blast media. I'm assuming sand isn't used that much anymore, because I haven't seen any offered at the few places I've looked. Is it too abrasive?
Another question, what are other applications for using a blast cabinet, (other than the obvious) I'm aware of cleaning rust off metal, using it to apply a finish to steel. Are there any other cool things I can do with it? I've seen sand blasting done on glass to etch it, but I'm refering to knife related applications. I go to the best dawgs in the pound, whenever I have a queston, I appreciate your advice, help and opinions, THANKS!!! Rex I keep both AO and glass beads in the shop for blasting, here are a few of my thoughts on each:

Glass beads in med/coarse produce a very smooth flat matt finish. On hardened materials it does take some time, as they are not all that aggressive. Durability is great on glass beads...I've been using the same batch for over 3 years with no noticeable degradation in how they work.

AO (Aluminum Oxide), especially in the grit that you mentioned is going to be super aggressive. (I also have 70 grit AO), and will leave a MUCH coarser finish, and if your not careful will flat tear up many materials. AO will generally last forever.

In my experience AO works much faster, and leaves a much more even finish with less time/effort than glass beads. I have been looking around, hoping to find some 180-220 grit AO....and if I can find it, will likely stick with that.

Each abrasive requires specific air pressure to work it's best....that pressure is going to depend on which type of abrasive your using, and more importantly the particular gun/nozzle that's in your cabinet. With my setup, glass beads work best at around 70-80psi, and AO works best a 90-110psi. The first time I tried to bead blast a knife blade it was a D-2 blade. I was using my newly purchased Harbor Freight blast cabinet and glass beads. During the process I thought I heard someone in the shop behind me laughing ( I was in the shop alone.), I stopped blasting and realized it was that D-2 blade laughing at the glass beads, that blade looked as shiney as it was when I started. Shortly after that I was at The Blade Show and asked another maker how he got the bead blasted finish on his D-2 blades and he told me that you have to sand blast them first then bead blast them. The next time I tried it I got some playground sand from Home Depot, used that first then the glass beads , it turned out just right and thats how I do it now. I now have 2 blast cabinets so I dont have to remove one media then the other to complete this process.

Hi folks, I recently purchased a blast cabinet and compressor to try my hand at this type of finishing. I set the compressor at 100 psi and began with med. glass bead using an 1/8" nozzle. On a heat treated SS blade there was very little effect if any but on 6AL4V it made it cloudy but did not remove much if any of the handling marks present when I buy it. Not a very nice look.
THEN I removed the glass beads and put in silica sand everything else the same. The finish on the blade was a little courser than I wanted but thought it might be acceptable until I saw that I had warped the shit out of it. Bad deal. I did try the titanium and it also warped that however that was a scrap, the blade was not! I turned everything off and here I am begging for help. Any advice would be appreciated.
Thanks, Gene I probably have the same type cabinet you have - Harbor Freight table top. Get a piece of stainless tube with the same ID as the hose. Bend it in a U with about 8" of straight on 1 side of the U and about 2" of straight on the other side of the U. Drill a 1/4" cross hole at the low point of the U. Take the straight pipe on the end of the hose which came with the gun off and throw it away. Connect the short end of the tube to the hose. Keep the long end of the tube above the sand level. You are now pulling air in through the long end of the tube and sand in thru the cross drilled hole in the U of the tube. This will give you a much higher flow of sand. I am running it at 100 psi.

I use Grainger P/N 5WO22 on Rc60 S35VN to get a nice matt finish. If it is too coarse, use 3M ultra fine sanding pad to knock the tops off the finish.

The only problem I have is the dust inside the cabinet. I have a shop vac hooked up to the exhaust port but I still have to stop blasting every few seconds to let the dust clear out. Anyone have any thoughts on how to exhaust the dust better?

Tim the "last" company i managed was a powder-coat firm, blasting is always the killer....the more CFM of air the more work you do, in our wheel cabinet (could hold a 22" rim) we were running a screw compressor that gave aprox 125 CFM @ 110 PSI, depending what was being blasted (substrate metal & finish required) media was changed, full clean down then re-loaded. pressure needs to match media.
As for dust clearance, are you in a built-up area? if not a 4" dust collector for a wood shop is great (am sure harbor freight sell them) but if you have local neighbors look at a "cyclone" filter after the blower. just my 2% the "last" company i managed was a powder-coat firm, blasting is always the killer....the more CFM of air the more work you do, in our wheel cabinet (could hold a 22" rim) we were running a screw compressor that gave aprox 125 CFM @ 110 PSI, depending what was being blasted (substrate metal & finish required) media was changed, full clean down then re-loaded. pressure needs to match media.
As for dust clearance, are you in a built-up area? if not a 4" dust collector for a wood shop is great (am sure harbor freight sell them) but if you have local neighbors look at a "cyclone" filter after the blower. just my 2%