Anybody following this? Sandblastig Engine parts

[StanTheMan]

in this thread, The OP is a bit of an artist. Goes to extremes to make it look like Porn. And perhaps do things right.

but the interesting part is that Keith & Lance have tuned in & talk about thier experince about using Aluminium Oxide for sand blasting. And the trouble they had with the engines they've built for customers

https://forum.miata.net/vb/showthread.php?t=637597

thoughts?
experience?

[1600Dave]

My thoughts would be not so much "How did Aluminium Oxide end up inside my engine ?", but "How did ANY foreign body end up inside my engine ?"

Engine building rule #1 - absolutely everything must be scrupulously clean - applies no matter what media is used (sand, AlO2, glass beads, etc, etc). Obviously there may be more to it than you or I know, but to say an engine that I built contained remnants of the blasting media would hint at not being fussy enough with cleanliness.

[manga_blue]

I just do everything possible to avoid using any abrasive medium anywhere near internal engine parts. I scrape, brush and scour. There's no way I'd blast internals. The only time I use abrasives is for porting and polishing with flappy wheels and cut-down belt sander strips, then I get obsessive about cleaning it all out with triple wash and rinse cycles with very hot strong CT18 solutions. I take it to the stage where I can wipe the surface with a clean white soft cloth and it doesn't leave the slightest smudge.

BTW when I do blast I just use beach sand. It works almost as well as bought stuff and it's incredibly available around my place.