Today I picked up a HF blast cabinet since it was on sale. Yea I know most if not all the HF stuff is junk, but I got it just for the cabinet really, even though I had to seal EVERY crack and crevice on the damn thing to keep from leaking, but all works decently well now. Here's the one I picked up, says 9.5cfm @ 90psi, 125psi max: We really don't do a ton of blasting, but we do enough where if I can get this thing to work right, it'll pay off really quickly, so this should work out fairly well for us. I got the 24 grit walnut shells and those barely do a damn thing to steel parts. I blasted an aluminum bell housing with them and it took all the paint off great, looks nice and clean now. Now I have a set of '40 Ford wheels I need to blast, some backing plates, lever shocks, headlight buckets, shackles, etc... what would be a good media to use for parts like this? The walnut shells barely phased the wheels really.. They all have pretty heavy gauge metal or are cast besides the buckets. I need to remove paint and some LIGHT rust, nothing horrible. I tried to search for some products, but I didn't find a definite answer. Thanks in advance fellas!
Just don't use sand, it can kill you. Even with the best precautions people are still getting silicosis. "Black Beauty" is also bad for your lungs. If you can find specular hematite it has the same abrasive qualities and no silicosis (and it's reusable). gary
For a cabinet, consider aluminum oxide or StarBlast. Glass bead works great, but it breaks up on impact and after a few runs will be too fine to do any good. All of these are abrasive media, which means they'll cut rust. Be careful with thin metal parts.
Depends on what you are blasting! Walnut shells are for trans housings, and stuff that might harbor residual blasting media...the shells will just break up if they are present. Glass beads for doing aluminum...keeps the surface "peened" like aluminum should look like. Aluminum oxide...best for FAST acting rust and paint removal, on steel. Can be used on softer stuff, like aluminum, but VERY carefully, it's agressive. Long life, too, less dust, but the most expensive. Oh, yeah, also wears out your blast cabinet parts fast, as well (nozzles, pick up tube, etc.) Other media..'in between' on both prices and perfomance. I think Eastwood has a good chart of media, and what to use it for in theri free catalogs.
Media recommendations above are all correct. Here's a couple tips- Remember those overhead projectors they used in school? The transparency films are a cheap, readily available cover for the inner viewglass. Don't blast without one or you'll regret it. Get a real gun after it's a few months old. The HF units have a cheap tip that wears real fast. Find a decent gun with carbide nozzles and it'll have much higher particle velocity at the same air pressure. Buy several size nozzles, (3/8, 5/16, 1/4 if there's a small compressor) and play around to see what your air system, media, and blast style prefer. Nobody ever recommends this, yet people stand at these machines for hours without knowing if it coulda been 30 minutes less. When a nozzle has enough wear that you can drop a pin 1/16th larger than rated size in, throw it away. NOZZLES DO WEAR OUT. It's not putting velocity in the particle, it's wasting your time and compre$$ed air. For this reason it can sometimes be good to undersize new nozzles, especially if you're pushing air consumption limits. They'll hit the sweet spot mid life instead of starting great and sliding down. good luck!
PMB type 5 is good doesnt streak or leave harmful residuals. GPX is starting to become popular. Wheat or Corn Starch based media pretty much all GPX is. Its pretty cheap per barrel and has a good pass life. Most important thing about blasting isnt always the media you use but in how you use it.. ie your distance from work, angle of noozle, psi/cfm ratio, so on so forth, knowing the signs of when you media is nearing its max pass. Yes different media have diferent hardness and fracture rates, nominal size. blah blah blah. Short in short..read up on it, everyone is going to diferent opinions, experiances.
Thanks for all the info fellas. Our air source is from a HUGE supercharged rotary compressor. They use it in the factory with the 200 ton presses, shears, etc where our shop is at. I think it is regulated at 115-120 psi. All GREAT info, thanks again guys!
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