Anyone blast with fine Walnut Shell media???

Anyone ever use fine crushed "walnut shell" media for abrasive blasting?
Before I buy 25# of it, I'd like to know the finish it would leave on aluminum?
I have always used fine micron glass beads. My favorite!
But I was at the cheap chinese tool store and was reading it polishes metal and rocks put in tumblers? Less aggressive on materials?

z1kzonly wrote: Anyone ever use fine crushed "walnut shell" media for abrasive blasting?
Before I buy 25# of it, I'd like to know the finish it would leave on aluminum?
I have always used fine micron glass beads. My favorite!
But I was at the cheap chinese tool store and was reading it polishes metal and rocks put in tumblers? Less aggressive on materials?

It is used by bullet reloaders to clean brass cartridges to like new condition.

Should be fine

Dave

Walnut shell is one of the least aggressive blast medias available. The real question is whether or not it's sufficiently abrasive enough to do the job you are intending? Walnut shells are good for something like cleaning carbon off the top of a piston and/or the combustion chamber and ports of a cylinder head. If you have some corroded parts though I tend to doubt walnut shells will be aggressive enough to remove the damage.

Yes, Thanks Guys, I am re-doing a Mark II Smog cylinder head and stock barrel & 1015 pistons.
Yes I will use aluminum oxide first to cut down the black paint first, then I always finished with glass.
Just might try the walnut shells, I always wondered if I could blast plastic covers with walnut to get that paint out of the seams and crevices of parts that have been re-painted. I have had paint jobs that had almost a 1/16" of material built up. And God awful Dupont "Imron" enamel from the 80's That paint was has hard as Powdercoat!

It's what we used to clean pistons when rebuilding Lycoming pistons engines for light aircraft. If it's good enough for the FAA bureaucracy it's good enough for me. We also used some sort of chemical stripper that is probably illegal nowadays too. It reportedly would dissolve Volkswagen engine cases. Trichloroethane perhaps?

I know a few car guys that use it to blast sheet metal parts to strip paint
they say it doesn't build as much heat.