From: IAN MOORCRAFT(UK)[email protected]
Date: 27 Dec 2002
Time: 06:06:07
Remote Name: 213.123.64.146
Graham, You should not remove corrosion on aluminium with a grinding wheel, in the aircraft industry "any" mechanical means of removal is not allowable, the reason being that the surface becomes plastic through frictional heat generated with the result that a new skin can be formed over the top of the corrosion making it invisible, but as the damp penetrates the electrolytic effect starts again between the grains (inter granular corrosion) of the metal, all that is ever allowed is removal with hand rubbing papers (and it takes forever), once the inspection department is satisfied that all corrosion is removed a yellow chromate etching primmer is applied as a base for the subsequent paint finishes. I would say if you have places where the corrosion has come right through, cut it out and weld in new metal, otherwise you will not be able to make any guarantees on the future finish (especially if you live here in damp and dreary England) Regards Ian