afb carb

[Phil A.]

Has anyone used muratic acid on aluminum before? I have an AFB that is weathered on the outside of it, and after soaking in carb cleaner for 3 days it has not removed the weathered corosion. The inside cleaned up nicely. I was wondering if the muratic acid would hurt the aluminum. Thanks for any response I get.

[Joe L.]

Re: afb carb

phil-----

Muriatic acid is an industrial grade and diluted form of hydrochloric acid (HCl). It will react very rapidly with aluminum and dissolve the metal, itself. I don't think that I'd use it on an aluminum carburetor body. However, if you wish to try it, I'd first test some on a scrap aluminum carb body casting.

A better choice for cleaning an aluminum carb body would be to use a dip carburetor cleaner like those sold by Berryman's or Mechanics Brand. When fresh, these will do an outstanding job of cleaning carburetor parts. However, the dip carburetor cleaners are a phenolic compound and are very toxic. ALWAYS use gloves when handling it or parts dipped in it (or your skin will smell like it for a week or more), use in well-ventilated areas, and ALWAYS DISPOSE OF IT PROPERLY.

[Craig S.]

Re: afb carb

Berrymans works very well as Joe mentions, but it is awful stuff to store and use. I have had trouble with the gasket on the top of the can going away, and one can corroded through the bottom, leaking onto my garage floor. The smell is horendous, but it does a great job. Craig

[Clem Z.]

anyone ever tried sodium hydroxcide

to clean aluminum? never tried it but i wonder if it would work.

[Duke W.]

Re: afb carb

Carb cleaner won't remove the surface oxidation. Go to a automotive paint supply store and buy a bottle of "Alumiprep". This is a diluted phosphoric acid solution.

Read the instructions and dilute it with water in a container you can dip the castings into. As far as dwell time is concerned, you'll have to experiment, but start with short times like a few minutes and keep repeating until the surface oxidation is stripped off.

Duke

[Joe L.]

Re: anyone ever tried sodium hydroxcide

clem-----

Aluminum is an amphoteric metal. This means that it has the property of being soluble in BOTH acidic and basic solutions. So, if one were to immerse an aluminum part in a strong caustic solution like sodium hydroxide (NaOH), it could be dissolved or seriously eroded.

A dilute acidic or basic solution might work alright, though. It would remove very little metal; just enough to render the part with a clean, fresh surface. The same thing might be accomplished using a strong acidic or basic solution, but with a very short contact or immersion time. In either case, the secret is knowing what concentration of solution to use or what contact or immersion time to use. Experience or experimentation are the only 2 ways that I know of to find out.

Commercial aluminum stripping solutions usually contain phosphoric acid, a weak acid which acts very slowly on aluminum, especially in the concentration that it is found in the commercial products.

Folks on the board have, in the past, recommended the use of Coca Cola. As silly as it might sound, it should work. Coca Cola, or any carbonated beverage for that matter, contains carbonic acid. Carbonic acid is another weak acid that should work as well, or better, than phosphoric acid since it will leave no phosphate salts behind to discolor or coat the part.

Most commercial anodizers use strong caustic solutions to clean aluminum parts prior to anodizing. Once again, the trick is to limit the immersion time to just the right amount of time. If the aluminum parts are left in the sodium hydroxide solution too long, all of the metallic aluminum will be converted to aluminum hydroxide, a white, gelatinous precipitate.

[Chas Kingston]

Re: anyone ever tried sodium hydroxcide

Joe —

I am the one who recommends Coca Cola for cleaning aluminum. Coke is acidified with weak phosphoric acid. Phos acid is the recommend cleaner because aluminum phosphate is soluble and won't precipitate on the parts like other aluminum compounds.

I have used the Alumiprep recommended by Duke, below, and it also works just fine. So does Aluminum Jelly, sold at your local Ace Hardware. But, Coke is easy to get and cheap.

FWIW — my 2¢

Geezer

[Mark Ring]

Re: afb carb

I might give some aluminum mag wheel cleaner a try. Eagle one sells some that is designed for cast aluminum without clear coat wheels. That is a bit easier to find at the Pep Boys or Auto Zone. I have used it on my other cast aluminum parts and have been pleased.

-Mark.

[Dale Pearman]

Re: afb carb

I LOVE hardware strength muriatic acid on valve covers especially. A black film forms which must be removed with 000 steel wool. The result on valve covers is an almost galvanic very clean grayish appearance just like original. I fear however that the judging standard has become white-white as in tumbling (reskinning).

Dale.