Restoring Cast Aluminum

[69importkilla]

Just curious, does anyone know how to get cast aluminum clean? I dont want to rattle can it because it never looks like true cast.

[Yoda4561]

Sand/ abrasive blast it. It will corrode rather quickly if left raw, so give it a clear powdercoat if possible.

[69importkilla]

Sandblasting would be troublesome at best. what about using some of these acidic wheel cleaners?

[justasquid]

A lot will depend on what your cleaning. If its just stained, cleaners may work such as mag wheel cleaner. If your trying to take of the oxidation, you'll be in for some work.

sandblasting will change the texture and the tone of it. If you can find someone that is able to beed blast it, that would be a better alternative to sandblasting.

also, depending on what you are cleaning, a stiff plastic brush and aluminum polish may work. Also, a plastic wire wheel on a drill works ok too, but you can't get into tight spots. But, it may give the aluminum a slight sheen to it.

[86Cutlass383SR]

I found a low-budget (even for MY wallet!) tip for my alum intake I was trying to clean up while off the car. It would be just as easy as being on the car.

I was getting a few items from Dollar General one day and seen some small wire brushes in a 3 pc package.. 1 nylon, 1 brass, and 1 stainless steel. I used the stainless one one day to get some of the nooks and crannies I couldn't otherwise reach. Less than $5 for all 3. I was pleased with the finish it left on the intake. Left a slightly gray-ish stock type look. I never thought about taking any before and after pics as I never knew it would come out so good with so little work.

[RBARNES496]

shot blasting looks great.clean up could be an issue, you dont want steel shot trapped in an intake.

[P-Designs]

Try some Muratic acid that you clean swimming pools with. Watch how long you keep it on there because I have had it turn colors on dirty(japan) Aluminum. Or try a product called Blue Lightening.
Tom

[69importkilla]

Whats this Blue Lightning you speak of? I presume the muratic acid I could pick up at a pool supply house?

[D Impala95]

We still don't know what you're trying to clean up.

I'd say bead blast or baking soda blast. If you're taking it to a machine shop it'll be bead blasted. It shouldn't cost you too much.

[69importkilla]

I picked up an LSx motor some time ago and the aluminum brackets/cylinder heads look like trash. The motor came out of a 04 Suburban so it was a little less than clean.

I have access to a bead blaster, but it would be kinda tough to work on the motor unless I disassembled it.

[Chicken Coupe]

Bead/sand blasting will clean the surface up fast, but it 'opens' the surface. It will deteriorate almost as fast as it was cleaned.

Soda blasting is gentler. It will not open the surface, but it also does not take off 'embedded' discoloration. You could use a cheap plunge supply blaster, a compressor, and a 5 lb bag from a Costco-like store.

IF YOU DO, MAKE SURE YOU ARE WEARING A HIGH QUALITY RESPIRATOR!

If you can't blast, there's only 2 real good ways to clean an aluminum intake.

Edelbrock recommends a brand of liquid rust dissolver.

I tried using Eastwoods, version that I had sitting around with excellent results. I 'assisted' the process with a toothbrush sized stainless steel brush. You have to soak, brush, soak, brush, etc.

A part of the directions of the liquid dissolver is to keep a steady wash moving over the area. I did it with about a 1/2 gal of the cleaner in a plastic storage box that was big enough for the intake to fit it, using a small submersible pump that I picked up at Harbor freight

It got back to 98% of it's original look. You can see some remaining dark discoloration/stains that I didn't fully address as I was planning to use it as a "cover" for my new motor, but went with a 67 tri-power intake. With a bit more effort, it would have been 'new'.

Just remember, this intake is 40 years old and was as grungy and discolored as it could get.





Before starting, the best method to clean is to wash down throughly with a few cans of brake clean. DO NOT use a water based cleaner concentrate. They oxidize the alum QUICKLY, making the whole process harder.

Next method is to send it out to be 're-skinned'. That process is used by restorers to reproduce the original 'as-cast' finish. I'm not 100% sure what they do to get the metal down to 'spotless', but the final step is to put the manifold into an oversize tumbler with rubberized abrasive beads. This process "closes" the pores that were put there from blasting or were left from casting, by 'wearing down' the surface. Here's a before and after of the 67 manifold.









This is the heat riser passage. It was choked with exhaust carbon when I sent it out.



The ONLY recommended method to keep it looking good is to spray with brake clean and wipe with a clean, absorbent, lint-free cloth (like a cloth baby diaper or layered cheese cloth)

The company I used to refinish and repair the intake was http://www.z28camaro.com/restosvcs.html

[RBARNES496]

[QUOTE]That process is used by restorers to reproduce the original 'as-cast' finish. I'm not 100% sure what they do to get the metal down to 'spotless', but the final step is to put the manifold into an oversize tumbler with rubberized abrasive beads.








That looks like shot blasting. Clean fresh cast look not chalky like bead blasting/sandblasting.

[Motown 454]

I have tried safest rust remover on metal ,but on their site they use it on aluminum. Its suposed to be safe. I was going to try it on my transmission but haven't got to it yet.
Here's the site http://www.ultraoneusa.com/
Check this out http://www.safestrustremover.com/Cometresto.asp?slide=5

[indyjps]

EZ off oven cleaner, since youre trying to clean them on the engine.

[Skip Fix]

I used EZ Off on an old Kart motor. Changed the aluminum color to a dark gray.

Also on your pan on the bottom of the intake-might want to pull it off to be sure there is no residual shot/media under it. If the rivets are the same as the 348/409 intakes they are available new.

[astroracer]

Try some Simple Green and a wire brush... Did wonders on my buddies 4.6 in his Mustang. Simple Green is some amazing stuff.
Mark

[Ron.in.SoCal]

Not sure this is the best answer from above, but a tip I got from a from a boat shop on my satin cast lower outdrive - CLR and scotchbrite pad (wear gloves). Worked like a charm, but required redo over time...