Best Blasting Media process for polishing?

[tomg552001]

I just recently purchased some blasting equipment because i am sick of doing everything 100% by hand. I am polishing mostly cast aluminum and i was curious as to the best way to blast it to get it to the smoothest point possible. I was thinking of getting the coarse 100 grit glass bead then after using that switch over to a extra fine glass bead then from there to wetsanding before the final polishing. Is this the right way to go or should i use a different approach? Please let me know so i can order from caswell asap.

Thanks

[mcaswell]

It's not an easy question to answer, because it really depends on the state
of the metal in the 1st place.

The rules are: Start coarse and work down through the grits. How course you start depends on its state.

I think your original suggestion is ok. You might have to go coarser if the
metal finish is rougher, but you can always add another grit later.
It also depends on the size of the parts. We like tumbling in corn cob for a
super FINAL finish.

[tomg552001]

Well i already went ahead and ordered the medium and extra fine glass bead. I am going to be polishing cast alum parts mostly with casting dimples and pits. I'm going to test this and i guess if it dosnt work order a different grit.

[fosgate99]

tom, post back with the results. I wish to do the same thing you are doing. I am polishing a part right now that i cannot really get into.

[tomg552001]

Well the medium grit, 60-100 i believe works pretty well at removing most excess but is too rough for polishing. I havn't tried the finder 325 grit yet, but will soon. I'm sure with the medium then the extra fine with some wet sanding and it will be just fine.

[fosgate99]

I just wanto to knock down the casting pimples, then i can hit it with the felt bob. Will it do that? It's on aluminum.