Technical How do I clean up old cast aluminum

What is the best, least damaging method to clean up cast aluminum parts? 4 Buick aluminum drums need a freshen up, and I’m looking at options and opinions. Bead blasting, chemical soak, other options? I’ve searched for threads but don’t have the correct search words. Hey, remember that I’m semi computer illiterate…

Thanks and as always let the verbal beating begin

 

bead blasting makes everything new and wonderful. that's what I'd do

 

I agree with the bead blasting. HRP

 

I had a dirty aluminum intake, bead blasting made it like new.

 

Yes, bead blasting or soda blasting will make those Buick brake drums look like brand new. This is the best option for those drums.

 

I wonder how totally awesome would work. stuff worked killer on carburetors

 

Bead blasting will leave the surface clean and uniform, but it will not look original. The surface roughness will also be difficult to keep clean. Vapor blasting, If you can find someone who does it, will leave it as close to new as it will ever get.

 

Polishing will leave a surface that is clean and easier to keep clean in the future.

 

There are products on the market that brighten aluminum I used to use it when I would restore travel trailers... It's not a miracle worker I don't want to lie and say it is but it's a pretty substantial difference...
Here is a YouTube short unfortunately the guy goes from grungy to done without showing it working I'm sure there are other videos
https://youtube.com/shorts/8K_bEvlWoEw?si=urI8mE_hoOCDnxoL.. I have never used purple power brand I think the one I used is no longer made It was made by CRC but I could be wrong I mean I'm trying to remember 15 or 20 years ago.

 

I have cleaned up a number of Buick finned drums. Some chemicals discolor the aluminum, so I give them a light blast with used glass beads and then wipe down with Gibbs.

 

Guess I’ll check with a couple of friends with blast cabinets. Maybe some adult beverages will grease the skids…

 

get yourself a blast cabinet, and a decent compressor, and you'll find all kinds of stuff that just has to look nice, now that you have a blast cabinet.

I got rid of mine, and now I can build stuff that looks like crap. It's very liberating.

 

Bead blasting works great and is addictive. If you have a KW or Peterbilt shop nearby they have good stuff for taking care of aluminum.

 

If you want to do it on the cheap "around a $100 "get a speed blaster and a bag of soda and blast the cast aluminum.
Soda will not alter the cast surface; it looks like new cast aluminum. I have been using this method on intakes for a few years and it works great.
Siphon-Fed Speed Blaster - TP Tools & Equipment
50 lbs. Extra Large Grade Armex Soda Blast Media

 

this is always a sticky one , such a porous surface is extremely difficult to clean without boogering it up , aluminum with age takes on a natural patina that is impossible to replicate. sandblasting looks like poo, glassbeading makes old parts look as if new , ive seen many vintage parts ,intakes, heads etc that were beautiful until sombody boogered em , after 33yrs on the clock doing restorations and rod building about 3yrs ago i finally found the solution ,, dry ice blasting ,, Google it ,, removes all everything does not touch the patina the first time i tried it on my own parts i was terrified , original sharp heads and original early post war navarro intake , turned out beautifull , at one time someone had cleared the heads , came off didnt mess with the aluminum ,, you will have to find somone that offers this service as the equipment is specialized, detailing shops are moving into this ,, i have found it the end all be all for cast aluminum cleaning ..
fabricator john
miss you dad

 

Bed blasting works, but as mentioned, it is not original and the new surface is easily stained. I did all the stuff on an OT engine and it looked great for a short while. It aged fairly gracefully, too, but did look weathered and wasn't easy to keep up.
I've heard that shot blasting closes up the surface, but wouldn't use it on the fins, more like an intake.
Vapor blasting or dry ice blasting is good, but not a miracle on aluminum. Your drums aren't bad, but for an example of ugly aluminum being dry ice cleaned, check RE Performance UK video a few episodes back. They did a V8 valley that had been heavily stained. EDIT: Warning, OT parts involved.
www.youtube.com/watch?v=ddrQ-Czb_Yo
A vibratory tumbler would do a nice job, but you'd need to find a business that has one and is willing to toss your stuff in.
I'd be concerned with a dip, due to the dissimilar metals on the drums. Go easy with stuff that is 'fast acting'. That's what batteries and cooling system erosion is, dissimilar metals in solution.

You well know the triangle, Dave. Cheap, Easy, Fast. Pick two.

 

One thing to mention about any kind of blasting is that if there's grease or heavy stuck on gunk, that really should get cleaned off before the blasting, even if it's just carefully scraped. You don't want to focus your bead blasting in one area too long, if you have to erode a big glob of snot off with the blaster, a lot of times it'll leave a shadow around that spot.

I never tried dry ice but it sure looks cool on an internet video.

 

The 90 fin drums are just a little grungy. The 45 fin drums were painted! for some reason, and not in a good way. So I need to do something. Soda may be a reasonable option. I’ve used plastic blast media on steel, and I’ve seen dry ice blasting, but never on aluminum. Maybe squirrels attitude is the best way…

 

When I worked for AMF, the weld shop used some stuff called Alumiprep to clean aluminum, I "requisitioned" some and it made some old motorcycle cases look like new.

 

@MCjim this stuff?
https://www.aircraftspruce.com/cata....php?msockid=28025bd26af361bd3afb4e696b71608c

 

The automotive machine shop I go to has a "cold tank" for aluminum parts that cleans most aluminum up like new. I've got to get my Offy intake down to them and have it cleaned.

 

Give them a bath with realy hot water and Dawn dish soap, then use Eagle One mag wheel cleaner



I stripped the paint with paint remover first

 

Most likely, it was just called Alumiprep back when I used it, hopefully the new stuff hasn't been 'improved" too much; it was quite a few years ago.

 

Perfect, Jim!
I've tried soda blasting an Edelbrock aluminum intake. It did very little good but I spray-bombed it afterward and that proved satisfactory - at least meeting my shoddy standards.

 

Thanks for so many responses. I’m getting the idea that I’m in for some serious cleaning effort. Time or money? Well, I’ve got more time than money, so …

 

While blasting looks good on intakes and stuff, it doesn't look right on Buick drums. Wash & scrub clean, then follow up with aluminum brightener like they use on semi wheels and trailers. NAPA has some.

 

I have my own blasting cabinet and use glas balls for aluminium. They are between 0,3 to 1mm diameter. Pressure is low so as to not crack the balls. The surface gets hammered by the balls and all the open pores get closed. This leaves a very nice almost shiny surface that does not attract dirt and is easy to clean. The usual used broken glas or sand is roughing the surface - the balls just smooth it.

 

Dave, most Servpro shops do dry ice blasting to eliminate mold on surfaces. Might check with them.

 

NAPA sells a product called aluminum brightener, I don't know how well it would work on corroded aluminum, but it does a good job on surfaces that are dirty or stained. It's not meant for polished surfaces, but is good for cast parts. I've used it on motorcycle engine cases with good results, spray it on, scrub with a brush and rinse. One advantage over bead blasting is it doesn't change the surface texture. It's a mixture of phosphoric and sulfuric acid so it is nasty stuff, you definitely need PPE when working with it. They sell it in gallon jugs as well as 32 ounce spray bottles. https://www.napaonline.com/en/shop/...emicals/aluminum-brightener-cleaner/201806154

 

Best media to blast aluminum is plastic
Won’t mar the finish