Exploring the Joys of Vapor Blasting

I have been searching for a Vapor Blasting facility in Colorado springs for about two years. Found one.
I have always liked the appearance of aluminum parts after vapor blasting.

First lesson learned is that vapor blasting doesn’t clean paint, oil, grease, etc of the part. Witness the steel nipple on the one piece that I’ll need to remove and deal with separately.

In my spares are left and right thermostat housings and the other end of the water rail. I did one of each so I have essentially a simultaneous before and after. These parts started out pretty clean:

The next episode is under way: blasting one intake manifold and the housing that mounts the two carbs through which water passes to expedite warming (emissions control from the early 70s).

I spent 5 hours with a bench grinder and handheld drill with wire wheel fittings to remove the black powder coating on the intake. Too much like work.

I used aircraft paint stripper, paint thinner, acetone, and mineral spirits but nothing really loosened the powder coating in the tight corners. I got 98% of the intake clean but can’t get into the tight nooks and crannies.

One of my other intake manifolds is being hot tanked (to loosen the powder coating), media blasted (to clean the powder coating off the manifold) and then vapor blasted – -- in thirds. So one intake will have side-by-side comparison. Should have it back in a ~week.

Then the experimenting continues: some time spent behind a buffering wheel will attempt to remove casting marks and clean up the pits in the aluminum.

One semi frustrating thing about cast aluminum is that you apply your favorite process, it looks great, and then immediately the natural aluminum corrosion layer starts to re-establish itself and it goes dull. I know this is what happened at the factory but it is a little disappointing after all the work. I have to admit that my go-to now days is Alumablast paint, from Eastwood and others. In this way, everything in the engine compartment is a consistent color. I know I was also introduced to ACF-50 on this forum. It works but in my experience gives a greyness to the color. I’m sure everyone has their favorite remedy for dealing with cast aluminum.

Maybe this stuff would keep it staying bright?

For my cast aluminum bits I’ve had good look with oiling them after blasting with Gibbs Oil, and more recently ACF-50. Both are designed to for this, and only need re-application every few years to keep the alloy “bloom” at bay.

You folks know that the aluminum oxide coat is really hard, and provides protection. So unless something needs cleaning up I am content to have a protected, dull part.