Will sandblasting cast-aluminum cause corrosion later?

[Harvey]

I've got a couple of very large cast aluminum pieces that need a thorough surface cleaning and roughing up for painting. Normally, I would use my glass bead blaster but these pieces are much too large for my cabinet. (They're about 24 x 24 x 24 inches each.) There's an industrial sand blaster nearby that normally does my steel jobs but I'm wondering if the high-powered sand will impregnate the cast aluminum and cause corrosion problems down the road?

Thanks,

Harvey

 

[Tony Wells]

No, not in itself, but if the media has been used before on ferrous materials, it likely is contaminated and there is a risk of embedding foreign material in the relatively soft aluminum. If new media is used there should not be a problem. As I'm sure you know, aluminum starts to oxidize virtually instantly, so try to keep the interval short between blasting and priming, and it goes without saying that a proper primer should be used.

 

[Harvey]

Thanks for your reply, Tony. I contacted a local (industrial) "metal prep" shop after I posted my question here yesterday and they reminded me that "soda" blasting is an economical, effective, and safe way to do cast-aluminum nowadays.

Harvey