Technical How do I clean up old cast aluminum

Question for you: did you clean the carburetors the same way? I’ve got some 2GCs to clean, and was wondering if your method would work on those as well.

I really appreciate all of the feedback. There’s a lot of good advice here that I’ve got to ruminate on. The only problem, I’m running out of space in the garage for another tool, machine, objet d’art. And the shed is bursting at the seams! Long way around the barn to say I’m not going to get my own blast cabinet. And I still haven’t gotten the garage reorganized since last fall! I know, I’m just a slacker!

 

When I build my tri powers the carbs are disassembled, sit in a 5 gal pal with dawn soap and water for a week. I clean them with nylon brushes to remove caked on grease, rinse, blow dry. I use glass beads to do the zinc, 80 grit sand on the bases, and finally baking soda for the clusters and floats. Yes, several small cabinets. They come out clean. If you have good cores with no varnish or white powder and internals are clean, skip blasting. Dip the cluster, float + brass, and hardware in carb cleaner for 4 hours. Spray all passages with carb cleaner and blow every hole and passage. Use a small flashlight to shine every hole to ensure all is clean. Walker 15289C kits give you all the gaskets no matter which small base 2G you have. It must be clean! Let me know if you have any help with the carbs. -Brian

 

I have been using ultra fine new glass beads in a blasting cabinet and air pressure around 35 PSI. this will not only clean the cast aluminum but closes the casting poor's helping to keep the aluminum clean . You could follow up with a coat of clear spray can lacquer.
This process , hands down is the way to go. I am speaking from decades of experience
\ Vic.

 

I've tried several things on Quickchange castings.
Glass beads are okay, but some of the glass stays imbedded and I don't like the idea of it getting washed into the gear lube and then the bearings. It does have a sparkle to it.

I didn't really like the finish left by viratory finishing. (Too Smooth)

My current go to is blasting with coal dust. (Black diamond) Available at Menards pretty cheap. I wash the cases before and after blasting and then they get baked to install the internals. Never found any residuals inside. This doesn't close up the pores and looks pretty much like the original finish. BTW, this works great on Magnesium too. Put some Gibbs of Flitz on and let it grey to a perfect color.

I too have several Buick drums to do. Let us know what you decide and post pics.

 

I’ll post some pictures when I get a round tuit and clean up the drums. Carburetors too…

I’ve really got to get the garage cleaned first… hoo boy, so much time, so little to do! No wait reverse those words

 

I most likely used Sprayway glass cleaner (foamy and smells great) with a nylon brush, then carb cleaner the same way.
I didn't rebuild them just cleaned them up, when I do rebuild I use the gallon size chem-dip, brake clean and carb cleaner with an assortment of nylon, brass and stainless brushes.
They turn out looking good enough for me, I'm more concerned that they give me all the horse ponies.

 

Good to know. Got one of those gallon cans under the work bench. I’ve got enough carbs that I can try one in it.