How to clean oxidized aluminum to original finish? These valve covers are pretty rough and I would like to take them to their original state. I don’t want to polish these, just bring them around to looking like solid originals for my 61 Pontiac. thoughts and ideas? Steve weim55 Colorado
Find a local machine shop with a cold tank for aluminum. They are pretty common with all the aluminum heads around now. That will at least get the crud off and give you clean metal to work on from there. I'd agree that walnut shells or soda blasting should clean them up. Non abrasive to the metal it's self.
NAPA sells an aluminum cleaner in a spray bottle that works pretty well and isn’t a polish. Sent from my iPad using The H.A.M.B. mobile app
Good luck with that...the original finish has pits in it now. Any process that removes more metal, will leave a different finish. But a gl*** bead blast finish will probably look OK, although it will be dull compared to the original finish.
I use trailer aluminum brighter and a scotch bright pad. You can get it for around $20. per gallon at a truck parts store. A little goes a long way. Be sure to wear rubber gloves.
I've used this and it works pretty well, it's a good choice for working on them at home if you don't have access to a blast cabinet. It is nasty stuff, so wear rubber gloves and eye protection.
Find someone that can tumble them. Can't tell where you are from but in Portland, Russ Meaks has a large tumbler with triangle shaped media that would makes those look pretty fresh. I've done intakes and (un***embled) aluminum heads before, awesome results.
You are aware that the original finish was polished, right? Not a mirror polish, but certainly more than 'as cast'. The only unpolished areas were between the fins and the interior surfaces. As a guy who has restored aluminum motorcycle parts that looked this bad or worse, it's not a real simple process to do right. My recommendation is first clean as much oil/grease/baked on **** off using solvent as you can. Then bake the parts at 350 degrees for an hour. This will 'boil out' all remaining corrosion that hasn't fully manifested itself. Failure to do this usually means that once you put the part back into service and it sees some heat, any deep corrosion will 'pop' back. Then sand blast the part, using a 80-120 grit sand. My experience is once cast parts get as bad as yours, soda or walnut shells won't be aggressive enough to fully clean them. Once fully clean, you then need to ***ess the surface. I'll go over all the flat parts with 220 dry sandpaper on a jitterbug sander to check for pitting. If you still find pitting, drop down to 80 grit paper and sand the flat areas until its gone, then take the scratches out with 150 then 220. At this point I'll swap to blue surface conditioning discs (AKA Scotchbrite) to remove the last of the sanding scratches and any remaining traces of the blasting. If you don't find any pitting, you can skip the extra sanding and go directly to the discs. Once you have a smooth even surface, then buff with a sewn cotton buff using red rouge compound which will be very, very close to the original finish. I will note that the better the polish job, the easier it will be to maintain the finish. If you go the extra step to a mirror finish, use gray discs after the blue before buffing, and a second buffing with a loose cotton buff with white rouge compound. Resist the temptation to apply any sort of clear coat over the finished part, corrosion will get under it and you'll have to strip the coating to repair it.
I just had a pair of Edelbrocks powder coated satin silver. I gl*** beaded them and they coated them. Powder coating fills in small imperfections pretty well.They look great and will not be high maintenance.
Dry electro polishing may work well. https://www.besttechnologyinc.com/electropolishing-equipment/what-is-dry-electropolishing/ Rather new process and not cheap but the results are first cl***.
I have watched my Brother bring back aluminum parts back to looking original or polished, just depends on how far you want to go. A kitchen scouring pad (one of the thin green ones) and lemon soft scrub. I have seen him bring back even badly pitted Harley wheels to like new condition. How much shine is how much polishing you do!. sounds Hokey (ok pun intended) but it works.
That's what i was thinking had some motorcycle cases vapor honed and they cleaned up nice almost like new with natural finish. For those that don't know vapor honing is done in a special water proof blast cabinet with abrasive and liquid.
In terms of low maintenance, this is the best choice. It will fill small imperfections, but be aware any clearly visible pitting will show if not sanded out. And if the part has heavy oxidation/corrosion, it's critical that the part be baked and blasted before coating to remove every last bit of it, because if you don't, the powder cure heat will cause any remaining to 'pop' and leave blisters in the cured coating. I learned that one the hard way... Any commercial coater worth his salt will know this. It should also be noted that castings can absorb oil/grease, baking will bring those out also.
we have dry ice blasting set up at work (Google IT) and it does miracles on aluminum castings totally micro clean and does not mess with the aluminum's natural patina , the first time i tried it i was amazed , we have it for engine compartment and underbody cleaning( does not fool with factory paints wiring rubber etc ) , it uses granulated dry ice as a blast media and the process is like sand blasting but much gentler , machine can be adjusted for media size (it grinds it to desired size) amount of feed and air pressure all digitally , we started learning on some engine parts and i was amazed what it did to castings ,, i mean they only have the right look or natural patina once after that its like "nice part.(too bad a idiot sandblasted it) " we've had this thing running about 8 mos and i took in a set original sharp heads that were given to me by a very old friend of my fathers they have turned out beautifull ,going on my 27 , leaves the aluminum perfect .. fabricator john miss you dad
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