Larry,
The "Slag" is a byproduct, it's Coal Slag.
I got mine from a friend who runs a golf course. They use it , not as an abrasive, but for helping to warm the greens in the winter to melt snow when it is sunny out, since the slag is black.
Here is a link for informational purposes only, i haven't dealt with thesre folks:
Slag
Ask any shop that does professional blasting in your area, and they should be able to direct you to a supply of the stuff.
Also, Aluminum Oxide is a very good abrasive "cutter".
Here are some seat of the pants methods I use for recycling blast media:
Spread out a tarp or some clear plastic. Use a piece of plywood as a back stop, but not too close or it will deflect media back at you, think "Sand storm".
Once finished blasting, you will have a good deal of media on the tarp.
The problem is you will also have paint peices, scale, etc.
Pour it through a piece of window screen to get out any larger chunks.
(Don't let your wife know you use her kitchen window screen for other purposes).
You will have fine dust in with your media, which makes for cloudier blasting next time around. I have heard of people "washing" their blast media, to rinse out the dust and dirt, then you are looking at a day or so for a drying cycle.
You can also construct a portable/temporary blast "tent" out of 2x2s and clear plastic, just cut some slits/air vents in the back, so the blast media doesn't come back at you. Use a tarp floor to catch the media.
Harbor Freight does have 25 lb. boxes of various blast media, so you could try some Alum Oxide, for example, if they are within a decent proximity.
if you want to blast aluminum, brass and lighter products, you can use walnut shells, corn cob media and such, HF has them also.
The Playsand flows nicely, but keep as much moisture out of the sand and system as possible. We have humid summers here on the east coast, so, I do battle the moisture, which can cause clogs and/or poor flow.
I have seen people use regular construction grade sand for ugly super-rusted pieces. I shy away from it due to it's usual high moisture content. If you have a way to dry the sand, do so before usage. Simply spreadeing it out loosely , over night, in low humidity will do the trick. Then I put it in a used 5 gallon bucket with a sealable lid.
My blast hood is long gone. A used pair of Motorcycle, ATV, Snowmobile goggles works well, then wrap a T-shirt around your head and face , desert-nomad style. If I need to be up close, I'll grab a small piece of plexi-glass and hold it up to keep some of the blast directed away. Those disposable white "space" jumpsuits also keep media out of your clothes.
Have fun Larry, Blast away!!
