In article ,
NT writes:
Hi

A quick question... which of the following would be best as a first
paint coat onto oxidised bare copper water pipes?

household oil undercoat
red oxide primer
modeller's enamels
smoothrite
acrylic
emulsion
1 coat marine paint - think its International polyurethane, not sure

There's HCl on site for a quick etch, if that would help, but I doubt
I'll have time to go buy more paints.

Depends what paint finish. Copper doesn't need a primer for normal
decorative painting. I usually paint pipes with gloss paint - the
gloss surface reflection tends to make the pipe look smaller than
when painted matt. With gloss paint, depending on the colour, much
of the opacity is in the undercoat, and you may need two undercoats
to cover a black pipe with white gloss. (This is true of the high
volatiles ones - I've managed to avoid the low volatiles ones so
far, so I can't comment on those.)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]