Blasting media question

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Woodsman341

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Hey folks,

If my question is in the wrong forum, let me know! I've actually asked on a few Facebook media blasting group pages, and got some answers, but unfortunately none of the answers was to the question I actually asked. Go figure. :)

So, I recently got a small blast cabinet to clean small parts, prep for paint, you know - the regular restoration stuff. The media I have was all gifted to me by my brother in law, brand new in the bags. It's crushed glass, but not labeled as to grit range, and just looking at it, you can see there's some very fine stuff and some fairly coarse stuff. The cabinet (a used marketplace find for $50), also had about 30 pounds of media already in it, used. So my question is - are there some sort of screens or sieves available that I can do a DIY sort? Not just to filter out the garbage in the used media, but to actually get two or three grits sorted into different containers for different uses?

I did a Google search, but I'm not sure of the correct terminology. I found some DIY suggestions for window screen, but that's really one size grid and not at all specific, and then I saw more expensive pie pan looking filters that go into the bottom of the cabinet that are basically advertised as just getting out the large bits to avoid clogs.

I appreciate any help.
 
I know this is not the answer you are looking for, but In my opinion, it is not worth the time to go through the filtering process.
Start fresh and you will know what you have.
 
I mix media. Plastic is good for paint removal, glass for aluminum, and aluminum oxide for rusty metal. You’ll be fine to use what’s in there. I use a smorgasbord of media sometimes, to “freshen up” stuff that’s getting dull. Run it.
 
I use fresh media only. I find that used media does not work as well. I also do not blast cast aluminum as it takes off the outer casting surface and it’s porous underneath. For steel which is pretty much all I blast, I use coal slag. Its way cheaper than aluminum oxide and work as well, maybe even better. If you need to blast aluminum, a vapor blaster works best and also on engine parts like rods and cranks.
 
I appreciate all the answers, but I'm more concerned with getting the grits into ranges that make more sense to me. 40-70 seems like a pretty big range to me, for example. And if I can filter it so I have something like 50 in this bucket and 120 or finer in another (after it breaks down a bit), that would seem more practical for different things being blasted.
 
You’re looking for a USS (U.S Sieve Size) mesh, and the number you find will be equivalent to the grit of your media. For example, if you find USS 36 mesh and pass your media through that, you’ll have 36 grit and FINER that has passed through. The larger grit will be left unfiltered. 80 mesh, you’ll get 80 grit and finer….so on and so forth.
 
Righty Tighty said:
You’re looking for a USS (U.S Sieve Size) mesh, and the number you find will be equivalent to the grit of your media. For example, if you find USS 36 mesh and pass your media through that, you’ll have 36 grit and FINER that has passed through. The larger grit will be left unfiltered. 80 mesh, you’ll get 80 grit and finer….so on and so forth.

I don’t know how you’d filter the finer media, I guess you’d have to have a series of different meshes.
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Thanks! I think that's exactly what I am looking for. Much appreciated.
 
You are doing this the hard way. But yes there are sieves/wire meshes in specific sizes that are used to determine grit size. These are laboratory supplies. You are better off throwing away all your "grit" and buying the proper stuff, then you know what you have the proper grit that will do the job without damaging the work. I alternate between glass bead and aluminum oxide which are readily available from local suppliers.
 
Murray said:
You are doing this the hard way. But yes there are sieves/wire meshes in specific sizes that are used to determine grit size. These are laboratory supplies. You are better off throwing away all your "grit" and buying the proper stuff, then you know what you have the proper grit that will do the job without damaging the work. I alternate between glass bead and aluminum oxide which are readily available from local suppliers.
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Although I *did* get the answer I was looking for, it turns out it's less than practical. I didn't figure that a few screens would be very expensive, and they aren't TOO bad, but still, it's about the same cost as buying a bag of media.

That being said, crushed glass should be fine for things like bolt heads, hinge arms, et cetera, right?
 
You have to realize that as soon as you start using that 36 grit, it turns into 50 or 80 grit and on and on. You have to really stay on top of cleaning out the cabinet or sifting to maintain a certain size. I am still running the same black crap I started with years ago. I'm sure it is smaller grit and it is full of rust and other crap because I've never cleaned/sifted it out, but it takes off rust and paint well enough to suit me. I'd like to try some glass for aluminum but it is too much hassle to clean out the cabinet for the little bit I need it for. I just turn down the pressure for aluminum or use another method.
 
ch1ll said:
I use fresh media only. I find that used media does not work as well. I also do not blast cast aluminum as it takes off the outer casting surface and it’s porous underneath. For steel which is pretty much all I blast, I use coal slag. Its way cheaper than aluminum oxide and work as well, maybe even better. If you need to blast aluminum, a vapor blaster works best and also on engine parts like rods and cranks.
Click to expand...
It's copper slag buddy.
 
Woodsman341 said:
No worries, I didn't know they made copper slag! I learned something too. :)
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I really like the copper slag. It's super sharp and fairly safe. It's scary how much silica sand I have blasted without proper protection. We have a mountain fairly close that makes silica sand really cheap for us. Used mostly for masonry these days.
 
I made a DIY sieve....small plastic bucket with small holes drilled in bottom. Strapped an old elec sander to side of bucket. Suspend/hang "sieve" with receiving bucket underneath.
Also turn psi up or down to help media last longer.
 
Crushed glass works awesome but its dusty. Requires cleaning the dust collector more often. I mix crush glass and black oxide in my cab and its a great all around media. I have a second cab with straight glass beads that I use for more delicate stuff.
Never heard of copper slag either.
 
If you have a Northern Tool store in Columbia, you can buy glass media there if you use all yours up. I used to use sand in my cabinet, and it worked ok. Even though it was inside the cabinet, I could smell it and that was scary, so I wore a respirator just to be safe! I switched to crushed glass from Northern Tool and it cleans parts much better!
 
MoparMike1974 said:
Crushed glass works awesome but its dusty. Requires cleaning the dust collector more often. I mix crush glass and black oxide in my cab and its a great all around media. I have a second cab with straight glass beads that I use for more delicate stuff.
Never heard of copper slag either.
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I guess it has something to do with living close to a large copper mine and a defunct smelter. We have mountains of tailings just like you do of coal.
 
On a cautious note, always wear a respirator when blasting with any media. Nasty stuff in slag and silica is a carcinogen as well.
 
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