How to get smeared Aluminum off of steel?

[neilho]

Dry laundry detergent is also a lye-based cleaner, slightly less aggressive. Activate with a little water to a paste consistency, scrub, then rinse with dish detergent to get all the lye off.

 

[IceCzar]

if you do use hydrochloric acid (muratic) the redox reaction will produce aluminium chloride and hydrogen.

Carbon steels, with an alloy content less than or equal to 6%, are often pickled in hydrochloric or sulfuric acid. Steels with an alloy content greater than 6% must be pickled in two steps and other acids are used, such as phosphoric, nitric and hydrofluoric acid. Rust- and acid-resistant chromium-nickel steels are pickled traditionally in a bath of hydrofluoric and nitric acid.

Pickling (metal) - Wikipedia

en.wikipedia.org

Passivation (chemistry) - Wikipedia

en.wikipedia.org

Steel Processing: Pickling and Oiling : Wilton Steel Processing

Wilton Steel Processing

wiltonsteelprocessing.com

 

[just Dave]

Would potassium nitrate (stump remover) work without damaging the rubber in the collet?

I can’t imagine any chemical work without disassembling

 

[rons]

At home Depot there are gallon bottles of 30% acidic vinegar. The food stores have bottles of 5% acidic vinegar.
Will the 30% vinegar be powerful like muriatic acid without the mysterious traveling vapor rusting everything in it's path?
The price is six times more too.

 

[sfriedberg]

I have a friend who took mill scale off a 3/4" HR plate overnight using the 30% acetic acid (vinegar), building a dam around the edge and letting a shallow pool sit on the surface. He didn't report any nearby rusting. (Doesn't mean it didn't happen.) The acetic acid certainly won't release any chlorine, because it doesn't have any.
However, I don't know if the acetic acid will preferentially attack the aluminum. I've always turned to lye to eat aluminum, not acids.

 

[rons]

Removing rust with phosphoric acid. What used to be bottled as a brush on product for rusted nail heads before painting.

Question: A bolt with say something like 10-32 with rust on the threads. Will a long exposure eat the threads.
What I notice is that a film deposits on the surface and if left there to dry it becomes something that can be painted over.
But the film can be easily removed and the area polished like new. Will a long exposure just keep eating away metal until
some equilibrium is reached. I mean by that, the concentration of solution due to past reaction time, volume of container, temp.

This Edfred stuff I use is the best product in all my rust removal days. It keeps a certain strength and can be reused.
I remember other products have to be rinsed with hot water. Edfred rinses with cold water and leaving it to dry is supposed to provide a barrier.

 

[akajun]

On gun parts I use cold gun blue and steel wool