Blast cabinet media selection

[GTOGreg]

Just bought a new blast cabinet and have a questions on which media to use...

I will be mostly cleaning up steel and aluminum pieces...old paint, maybe some rust/scale. One thing I want to do is blast my intake manifold and give it that "as cast" rough finish, as I had to do some grinding/smoothing on it.

I was thinking glass bead for general usage and alum-oxide for the intake manifold type use case? I appreciate your thoughts on this...

 

[dcayers]

I work for a piston manufacturer. We some times make newly designed pistons out of billet aluminum and blast them with stainless steel shot to give them the forging or cast type surface. Not for sure price of stainless shot.

 

[Mmfh]

I'm an engine rebuilder, I use a medium sized glass bead, Potters Ballotini beads, for everything. Aluminum, iron and steel.

If that manifold is supposed to look rough in the spot you repaired, you might have to beat it up a little to give it that look, give it a blast with some large new beads.

I've done a lot of crack repair on aluminum heads, most heads are not real rough but grinding and smoothing and than the glass bead process, its looks pretty much like the original.

Mm

 

[zruvalcaba]

I mostly work on guns (restoring, building, smithing, etc.). I use 70 grit Aluminum Oxide.

Zak

 

[cirrusaero]

I'm pretty sure that using aluminum oxide can get embedded into an aluminum intake and then could release when heated. You should stick to glass bead.

 

[ZRX61]

I use plastic for removing paint etc & glass bead for cleaning beyond that

 

[OccupantRJ]

I use glass beads to blast carburetors and such. In another cabinet, I use aluminum oxide for paint and rust and such.

 

[Greatbear]

Fine glass beads leave a flat, light gray finish on aluminum, an appearance of primer (and just as good as primer). Coarse glass beads leave a pearly silver shine attractive enough to use as a final finish. Grades in between mix the two effects accordingly. I use Potters and Skat Blast media mostly. Aluminum oxide does a great job of stripping rust and paint from surfaces, but cuts aggressively. Not recommended for dimensionally critical pieces. If you repair or restore items like carburetors, consider using walnut shells or plastic media. Plastic media lasts a long time, cuts slow but consistent, and creates almost no dust. Walnut shells break down fast, but leave plated carb finishes like those found on Rochester or Holleys mostly intact.

 

[floyd]

great thread. what PSI do you guys run, and does it vary depending on the media?

 

[Mmfh]

I have my cabinet set at 100psi. I don't change it, works for everything I do.

 

[sr71]

.....should also have a bag of silicon carbide for the really tough stuff (powder coating for instance)