Bead Blasting Media questions opinions...

McClellan Made Blades

McClellan Made Blades

Well-Known Member
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
 
Rex, I'm sorry I can't answer most of your questions. I can say that I've seen a few guys who have used bead blasting on micarta. Of course, I have no clue how they do it.
 
ao seems to work good i got the glass beads i had from tractor supply but the ao seemed better on blades that were heat treated
 
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.
 
murphda2 said:
Rex, I'm sorry I can't answer most of your questions. I can say that I've seen a few guys who have used bead blasting on micarta. Of course, I have no clue how they do it.
Click to expand...

Thanks Murph!!! You're a plethora of information, I wonder how you store all that information in that little bitty head of yours!!!!!!
 
EdCaffreyMS said:
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.
Click to expand...

Thanks Ed!
Now that's info myself, and I'm sure several other guys can use. Most of my equipment comes from HF, one thing I've noticed like with my steel cutting band saw, there are several companies that offer the same exact band saw, different colors, and I'm hoping (based on the prices) some upgraded components. I'll be happy to post a review on how well it works for me, do keep in mind that I've never used a blast cabinet so I don't have anything to reference it to, I do know what kind of results I want. My compressor goes to 125psi, I bought the medium screen glass beads from HF, that looks a lot like sand, and doesn't look anything like beads I may pick up some from Tractor Supply and maybe from some other places, to do a comparison between them, mainly to see what works best for me, and I usually do a cost comparison to see which is worth more costs if that applies. I know somethings cost more than others, and that extra cost is justified by better performance, sometimes! Thanks Ed for the input, I'll keep that in mind when I start blasting. Rex
 
This is the stuff I've been using:
http://www.tptools.com/Product.aspx?display_id=352

it's a mix of AO and glass beads. I really like the finish it gives for combat/tac type knives... I just got a new Kobalt compressor, and will likely be trying it out w/ the cabinet in the next week or two. It's a much better unit that the one I replaced, so I have little doubt it will do just fine. I'll post some pics of the finished project in the photo subforum when I wrap it up.
 
It may be worth noting that glass media comes in actual beads, and also in a form more like crushed glass. The beads are round and smooth and are much less aggressive than the other form, which are angluar, sharp-cornered particles. The latter is sometimes sold under the label of beads although it should more properly be called glass abrasive. The terminology used with these products can be misleading, it is worth paying extra attention to what you are actually buying.
 
I use a 50/50 mixture of 80 grit glass beads and 80 grit AO. I really like the finish this leaves.
-John
 
We use glass beads here at work to blast die parts. mostly D2 and A2. All are hardened first and ground and then blasted. The reason we blast them is because the come out of the EDM wire machines and they have rusty water stains or just discoloration. We have to blast out the dowel holes and other critical fit areas too so that they will fit.

You just need to get some good media and have a good ammount of psi behind it.

Search for my introduction thread and check it out. The first fixed blade I ever made is D2, and the bevel is blasted.
 
You must log in or register to reply here.
Back
Top