I have been researching for the best method to use for restoring the original finish to aluminum castings (carbs, trans. case etc.). I have bead blasted some parts in the past and found it to be too harsh. I have not tried walnut shells or vapour blasting. I have heard that dry ice blasting is not as abrasive and gives a better result than vapour but have not seen any examples. What is everyone else using and has anyone tried dry ice?

I have been using a small cabinet at home with garnet sand as the media. I run the air at 100PSI.

The result I get on alloy parts is, to me, a pleasing satin finish. I recently treated the body of a 44PHH Mikuni Solex side draught carb.

I didn't even mask off the ID lable, just sprayed around it.

Turned out very nice:)

When fresh, the garnet is very sharp but you can still control the treatment easily with varying air pressure.

I have treated all sorts of alloy bits from a 4 cylinder valve cover, inlet manifolds, to the carburettors mentioned above.

Below is a couple of pics. of an untreated carb. and a treated carb.

I haven't tried alloy polishing on this sort of surface [i don't like polished alloy on engines], but the mellow satin finish is great I reckon.

More images in the Gallery, pending approval.

Still getting the hang of this website:rolleyes:

http://www.classiczcars.com/photopost/showgallery.php?ppuser=13952&cat=500

Graeme - Can you describe garnet sand? I think it could be what we call black diamond here. Very sharp edged, fast cutting? I'm looking forward to see the pics you posted when approved. I followed your link to your imagestation album. Very impressive and recommended viewing.

Hi Ron, try the link to my Album, I know that works!

http://www.classiczcars.com/photopost/showgallery.php?ppuser=13952&cat=500

[Nissanman photo album on this site]

I have been notified that all images have been approved but for some reason, only 2 are visible:ermm:

I can't remember what # grit the garnet is, I think it ranges from 40 to 60.

It is very sharp when new, but the stuff that is in my cabinet now has been beaten to death and is now very fine and dusty.

Still does the job though, probably safer than when new:classic:

I keep all the used garnet, then if I need to do a large item outside the cabinet, I can stick a different gun in the bucket and do it on the back lawn.