It can be painted after it ages a bit. For best results use a quality metal
primer and paint.
Assuming it was just done, I would not paint before Spring of next year.
If you absolutely must do it sooner wash it down with a strong detergent and
rinse well. I usually use powder dish machine soap mixed strong enough to
feel slimy. I find it cheaper than a commercial product and just as
effective.
--
Colbyt
Please come visit http://www.househomerepair.com
Are you sure it's galvanized and not mill finish aluminum? Not sure
where you are, but around here there is essentially no such thing as a
galvanized valley. Standard is aluminum for the budget minded, and
copper for those with some spare dough.
In any event, I'd think painting a valley and having it last would be
problematic. Factories use a baked on finish, and you can't replicate
that at, or on, your home.
R
The first thing I was told was to wait at least 6 months before painting
galvanized metal.
Rainwater is naturally slightly acidic on acount of its reaction with
natural CO2 in the atmosphere. Over time, I guess rainwater's mild
carbonic-acid content would etch zinc-washed steel sufficient to allow
proper paint adhesion.
But... automakers a while ago went through absolute hell trying to make
paint stick reliably to zinc-washed steel, so I'm also guessing rainwater
alone might not do it for you.
--
Tegger
When I was working on a Core of Engineers project some years ago, there
was a request to paint some of our galvanized conduit. The painters told
me the pipe would have to be primed with what they called "green wash".
It was my understanding that the stuff etched the zinc surface so the
paint would stick to it. I heard of this being recommended:
http://www.autobodytoolmart.com/u-pol-acid-8-1k-etch-primer-up0741-p-15132.aspx
http://preview.tinyurl.com/3a9zoyd
TDD
You will either have to leave it to oxidise for a few months or paint
with an etch primer first. If you don't the paint will flake off.
This applies whether it's galv. or aluiminium.
I bet its aluminum, paint wont last long with all that water running
down it. There is prepainted aluminum in colors I would first ask the
roofer why he used silver, its to bad you paid him, maybe slipping a
smaller painted piece over the silver would work.
Or
Wait one year, then paint with any color you want. It will not
need primer, etc.
--
~~~~~~~~~~~~~~~~~~~~
DanG
Keep the whole world singing . . .
"Heathcliff" <heathclif...@hotmail.com> wrote in message
news:d84a99bb-3d38-4d7b...@c13g2000vbr.googlegroups.com...
What's your guess as to how long the paint will last in a valley?
That's an incredibly harsh environment. Expansion/contraction of the
metal from heat and cold, water scrubbing it with every rain, etc. I
just think painting it is pissing up hill. A shedding-paint valley
will look worse than a bare metal one. The metal tones down with
exposure, so it's probably just some new-roof-shock syndrome. The OP
will get used to it in time...and without making a new hobby for
himself.
R
When I was in college we had a mobile home with a galvanized steel "skirt".
Following the instructions we got at a paint store, we washed it with vinegar
and then painted with a paint specifically meant for galvanized steel. There
wasn't as much as a flake when we moved out, three years later. It looked the
same as when we painted it and a lot better than some of the far more
expensive aluminum the neighbors had.
When I installed the woodstove in the early 80s, some of the
transition pipe pieces at the ceiling were gavanised. I gave them a
thorough wash with vinegar and painted with spray cans of high temp
paint. They look just as good now as they did back then.
Harry K