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Discussion Starter · #1 ·
Guys

I have glass beads loaded in the blast cabinet - "Size: AD 70-140 US Sieve"

If I don't linger for hours, would you consider these safe for mating surfaces? I'm thinking I might to less damage with a light shot of these than digging (invariably a little gouging) around studs etc with a razor blade.
 

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Generally, I see no problem bead blasting gasket mating surfaces.

However...

I would not spray the engine block, as there is a very good chance you'll lose some beads into a crack or oil galley where it will get stuck. Until later.

Also, most Alfa aluminum castings have a nice surface treatment (probably a layer of pure aluminum over the stronger cast alloy), and blasting that will remove it. Instantly.
 

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About 30 years ago the Duetto head was vapor degreased and then bead blasted and cleaned again. The bead blasting had no effect on the aluminum casting, it still looks like new but you could imagine my horror the first time I changed the oil and found a couple of teaspoons of glass beads in the canister type oil filter! It must have been trapped in the oil or coolant galleries only to come out when the engine ran the first time. If you bead blast pressure wash the head well! Fortunately the filtration system must have done a good job as the engine experienced no noticeable damage.

I see no problem bead blasting gasket mating surfaces...I would not spray the engine block, as there is a very good chance you'll lose some beads into a crack or oil galley where it will get stuck.

Also, most Alfa aluminum castings have a nice surface treatment aluminum over the stronger cast alloy and blasting that will remove it. Instantly.
Mark
 

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Discussion Starter · #4 ·
Thanks guys. Should have clarified that I was mostly asking for non-motor components that have mating surfaces and fewer little passages for media to get stuck in. Transmission, fuel pump on my 912 and so forth.
 
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