Ignoramus5390 wrote:
On 2008-01-15, Bob Engelhardt wrote:

Mark Dunning wrote:

Have you tried the Electrolytic method of de-rusting?

...

Yes, I have. I prefer acid: it's much faster; electrolytic leaves a
really awful gunky residue; the length of the current path affects the
derusting.


I also prefer acid.

What acid do you use, Igor? I've read that the black oxide layer left by
electrolytic derusting actually sucks for painting on because it has a
significantly different coefficient of thermal expansion to that of the
steel, causing it to flake off. But I haven't put it to the test yet.

Best wishes,

Chris