Cast Aluminum engine parts - How 2?

LeMarque

LeMarque

New member
Have an '03 M3 (my first PAID) full correction project.



Any suggestions for products to clean/brighten/remove slight oxidation from these:



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P1010163.jpg
 
To actually accomplish what I think you wish to do, it's a very "involved process" and requres the use of an acid combo that is becoming more and more difficult to obtain.

There are some other ways to deal with it, but they are even more labor intensive.

You have "corossion" on most of the parts, that must be be removed, and the list goes on and on.

Should not wish to go into a complete system, may I suggest that you just use a normal wheel cleaner, and a stiff brush, get as much off as you can and flush the parts with water to remove the residue of the wheel cleaner, get them dry and apply a urethane finish to them.

Sorry, it's not what I would gather you want, but based on your post, it is about as good as I can provide.

Grumpy
 
Ron Ketcham said:
To actually accomplish what I think you wish to do, it's a very "involved process" and requres the use of an acid combo that is becoming more and more difficult to obtain.

There are some other ways to deal with it, but they are even more labor intensive.

You have "corossion" on most of the parts, that must be be removed, and the list goes on and on.

Should not wish to go into a complete system, may I suggest that you just use a normal wheel cleaner, and a stiff brush, get as much off as you can and flush the parts with water to remove the residue of the wheel cleaner, get them dry and apply a urethane finish to them.

Sorry, it's not what I would gather you want, but based on your post, it is about as good as I can provide.

Grumpy
Click to expand...



Thanks Ron



I think you saved me from trying to turn lead into gold. I'll take your advice and test with wheel cleaner (Megs Wheel Brightener) and post the results.
 
The best methods for concours level cleaning of cast aluminium is by bead blasting, but if you just need to clean use an acidic cleaner. Do not use a strong alkali as it will cause carbon spots that are very difficult, if not impossible to remove.



• Thoroughly de-grease the surfaces using Optimum Power Clean ™ and then rinse with clean water

• Clean surfaces with P21S Polishing Soap or Total Auto Wash

• Using a brass wire brush and Optimum Metal Polish scrub the aluminium surfaces

• Thoroughly rinse with clean water and then dry

• Use a polymer clear coating (Z-8 Grand Finale™ Spray Seal)
 
On my (older, e36) M3, I was able to get to many of those areas with my Dremel, using an extended flex-shaft and small buffs/brushes.
 
There are a couple metal brushes I use on parts that are aluminum yielding good results without compromising the condition of the metal. Get a bucnch of brushes and do some testing and tuning, if you will. (just not on a customer car) ;)
 
I've spent some time/energy attempting to polish those bare Al castings on my BMW (bike) but it was somewhat of a losing battle as the shine seemed to fade quickly.
 
Tom, which is why the key is "acidizing" with the nasty acid. It "makes the top mil or so of the aluminum denser" so it can hold a shine. The first time, may last a month or two, second time of acidizing and polishing will last twice as long, etc.

Grumpy
 
Ron, thanks. I didn't know that. I did buy some kind of acid. I think it was an Eagle One product that another person had mentioned and had good results with. I just got nervous having it around certain engine components :(
 
As well you should!

However, the Eagle One is probably not a HF/sulfuric blend.

To the a polishing job correct, it is best to disassemble the parts, acidize, if rough castings-bead blast them.

If not, sand with 220, then 600 or 800, followed by 1500 or 2000, then start polishing with cotton or felt wheels, finish up with a foam power ball.

Grumpy
 
Thanks everyone for the replies.



I think I'll try Ron's and TOGWT's solutions on different parts and compare the results and post back.



Or I may just ask the customer to return at a later date for that process.
 
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