In message , "dennis@home"
writes


"Tabby" wrote in message
...
On Jun 7, 11:09 pm, "Nightjar \"cpb\"@" "insertmysurnamehere wrote:
On 07/06/2011 20:21, Tabby wrote:
...

I wouldnt want to sand the zinc coating.

The main problems is that it would be extremely tedious to do. Zinc
dust, however, has no known long term effects on health and the short
term ones are readily avoided by wearing appropriate protective gear.

Colin Bignell

It can however ruin the galvanised coating, specifically when its
electroplated.

That wouldn't matter though.. zinc corrodes in preference to the steel
and that's how it protects the steel. If its plated there isn't enough
to protect the steel (well not for as long as the paint will).


I'd be quite interested to learn how most scaffolding is galvanised. I
was always told that hot-dip galvanising was the only "proper "
galvanising, and to avoid anything "spray galvanised". I assume this
referred to flame spray galvanising, where molten zinc is sprayed onto
the steel.

Is galvanising sometimes done by electroplating? I'd have thought the
sizes involved would have made the spray method the easiest.

Some of the scaffolding poles beside my shed show some yellow
discolouration, which I assume is very light rust.
--
Bill