Hi

Im fairly new to this. I have a SatBlast wet / dry pot and I want a nice finish on aluminium engines using an expendable media.A finish that I could just clear coat for that bare aluminium look.

what are my media options and how important is the right pressure ?

Thanks

Colin

I'll give it a try, you may need to provide more information.
If all you are doing is prepping the surface for clear coat or other organic coating, 25-50 psi with 180-220 grit aluminum oxide should be enough depending on your paint system and preblast surface finish. As cast surfaces may require 80 grit at 40-60 psi to meet the finish you want.
Different paint systems may require different surface preps.

thanks Charlie but the point is I dont want to paint, I just want a nice, bare aluminium look so its important to leave as smooth a finish on the alu as poss.
Preblast the surfaces are very dirty, baked on paint, baked on carbon maybe.

So this is more of a restoration project and not new production? I used the term paint to encompass the clear coat you referenced. What it now sounds like to me is that you are more interested in just cleaning the parts using media blast. Depending on the nature of what is on the surface, you may need to try different things. I suggest you start with 80 grit aluminum oxide at 40-60 psi and increase pressure as needed. If this finish is not what you want, switching to a finer media and/or lower pressure would be the next step.