How's it possible to tell if a part has been either bead-blasted or walnut blasted?

[H.G.P.]

How to tell the difference between the two?

Thanks

[Zeke]

I think it would depend on what kind of part....

[Porschekid962]

mmmmmm no idea. glass bead media comes in different grit sizes, as far as shells who knows.

would it be a big difference to you if it was one or the other?

[H.G.P.]

Originally posted by Porschekid962

would it be a big difference to you if it was one or the other?

Yes, I understand that pistons should not be bead-blasted in the ring land. So in evaluating a used piston that appearance is good, how would one make sure it had not been bead-blasted?

[Porschekid962]

wow, thats a big diff from glass media blastin. i just went over my alu. bike frame with the glass blaster at shool and it has a much more uniform, slightly shiny look to it.

[H.G.P.]

Is there a texture difference that can be felt to the touch also?

[Willem Fick]

Glass beads will leave a surface finish not too different from that of frosted glass in texture (smoother perhaps), whereas walnut blasting should leave the surface texture near to original.

Regards!

Willem Fick