Originally Posted By GLLHG

I don't disagree at all with what you say but two thoughts still strike me: (1) given the proensity of the chassis to flex, surely this must crack the coating and undermine it to an extent (2) in similar vein, as soon as any hole etc is drilled throgh a galv surface, doen't this, again, detract from the protection?

I may be wrong here and I'm no metallurgist but I thought this was why all the best resto jobs went for powder coating?
As I said, happy to be corrected thumbs
Cheers,
G


No - the galv wont crack. At the interface with the steel it forms a compound so the zinc is very stronngly bonded to the steel. Yes any hole will will ultimately reduce the protection because the zinc round the hole gradually gets used up protecting the otherwise unprotected steel bolt ie the zinc coating is sacrificial. So eventually when all the local zinc has gone both the bolt and the chassis around it start to corrode. How long this takes depends on the thickness of the zinc - no time at all if its electroplated steel but a decent time if its hot dip galvanised.

If you could only do one coat to a restored chassis it would be galv every time rather than powder coat. The latter is a good form of paint but [paint is what it really is.

When I was working I had a factory making steel fabrications and that included a galvanising plant as well as paint booths. Doesnt mean I know all the answers ( I'm not a metallurgist either) but I picked up saome knowledge along the way.