What is the best sand blasting medium for a aluminum intake manifold(z/28 3917610)?
I think that you will find that the quality restoration guys do not blast the aluminum intakes....they tumble them.
Sand blasting will permanently ruin the original surface finish - send it to Jerry MacNeish and have him do it right.
Sandblasting is a messy, nasty, highly abrasive process that will etch surfaces and wear away details like casting numbers.
After 36 years of this hobby there are very few automotive parts I might sandblast during a restoration.
plasic media does a very good job of cleaning aluminum. we do quite a few look like new when done without material removal.
John is correct in the comment "send it to Jerry"! I have used fine glass bead at 15-20 PSI on some small alum parts and it did a very nice job without changing the texture but again they were small in nature. And with that pressure it is a slow operation. You might be surprised as the cost for Jerry to complete his magic is inexpensive IMHO. He did our 610 intake, trans cases, etc., and everything looks NEW.....
If it'not a factory aluminum manifold, just plug up the threaded heater fitting and turn down the pressure and use sand. I just did an old Holly manifold and it turned out great.
I discovered a method that works pretty well and keeps the factory finish and patina. I first used Dawn liquid dish soap and a brush...water pressure and that cleans most of the oils off, then I used my wife's Tied powder detergent with a stiff scrub brush. It came out looking brand new! Good luck. GI JOE
Joe, how long does that still look good?
So far mine are still looking day one original and clean but I have not had my cars out on the road day in and out so I am not sure if it will still look new after lots of street duty. What I found is a cleaning method that cleans the road grim and deep stains off, bringing the case back to a clean day one look, preserves the natural finish and IMHO looks great. IF I had to settle for a media blast I would invest in the soda blast and or soft shell over glass.... but first I would try every cleaning method available, degreasers, ect... the Tied cleans deep and thorough but it does require you to scrub it in. JOE