CLEANING ALUMINIUM

[ralph thetford]

I have presently got my 1938 Ariel square four engine apart and wondered what is the best method of cleaning the cast aluminium crank case as this appears to be 'as cast' rather than a polished finished. Is there any liquid cleaner etc. that works well.

Regards Ralph Thetford

[john.whiting]

There is a cleaner used on ally truck bodies and bullbars that leaves a clean shiny surface,but its very noxious to humans.It contains 3% hydroflouric acid,and effective protective gear must be worn when using it.Just needs to be swabbed on and washed off.Most bikes have a roughish sandblasted surface on crankcase castings,saving polishing for timing cases and the like.

[DaveH]

I like the results of using a fine stainless steel rotary wire brush.

[paul.jameson]

I use wire wool to do the initial cleaning but wash the debris off very carefully and clean out all threads with a suitable tap then go round with a magnet. Having done that, if you want a brighter finish, you can't beat an old toothbrush and Solvol.

[nevhunter]

To remove any corrosion and clean use Alumiprep 33 and to protect the internal surfaces from corrosion use Alodine 1201. This is what aircraft alloy castings are treated with. Toothbrush or shoe suede cleaner brush (Brass) to clean surfaces and preserve as cast look without excess polish effect. The surface looks clean but not polished. The internal surfaces are honey coloured. Use as directed . May need dilution with pure water. Nev