Something I learned on Taryls Youtube, aluminum build up on piston (2 cycle)

[PTmowerMech]

I'd forgotten what muriatic acid does to aluminum. Eats it, basically. He was repairing an old 2 cycle lawnboy mower what had slightly scarred piston and cylinder. He sanded the high spots on the piston. Then to get the excess aluminum off the cylinder, he used muriatic acid to eat it off. Then honed it a little and voil'a.

 

[StarTech]

As long it cast iron or steel. Some cylinder platings also don't like Muriatic Acid. Ever use Sulfuric Acid on aluminum to remove rust and water corrosion?

 

[PTmowerMech]

As long it cast iron or steel. Some cylinder platings also don't like Muriatic Acid. Ever use Sulfuric Acid on aluminum to remove rust and water corrosion?

He even mentioned over cleaner get rid of aluminum.

 

[bertsmobile1]

Aluminium is soluable in just about every strong acid or alkali
We used to boil old barrels in a strong caustic soda solution ( Lye to USA ) to remove aluminium build up.
It also lifted the paint so did 2 jobs at once .

Iron & steel will also dissolve in Hydrochloric acid ( Muriatic if a less refined commercial grade ) but only when very hot .
We dissolve iron samples in aqua rega ( Hydrochloric + nitric acids roughly 40:60 )

So a crank with a build up of aluminium can be either dipped in cold HCl or boiled in NaOH
HCl works best if the shaft is degreased first while NaOH is a degreaser but will passivate so may need light scrubbing

 

[StarTech]

Just remember that Muriatic Acid will cause to iron, tin, and steel to flash rust if not neutralized and oiled after the cleaning.