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Paul Oman Paul Oman is offline
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Default Paint? Poly? - how to UV protect epoxy coating on wood gutters?

blueman wrote:
writes:


On Sun, 26 Jul 2009 20:14:43 -0700 (PDT), Joe wrote:


On Jul 26, 9:01 pm, blueman wrote:

As per an earlier thread, I ended up epoxy coating one decayed wooden
gutter (with multiple coats and some fiberglass) and one undecayed
wooden gutter that I just surface coated with the intention of
preventing future rot.

Now since epoxy is UV sensitive, I assume I need to coat the epoxy
with something to protect it from UV.

What would be the best coating that would stand up to the water-logged
nature of gutters and to sun UV exposure? I am looking for a solution
that requires the least maintenance and repeat coating.

Would you recommend paint? If so what type and is primer required?
What about a poly spar varnish?
Any other suggestions?

Note: after applying the epoxy coating, I noticed someone cautioning
against epoxy (or any other non-breathable) coating of wooden gutters
since trapped moisture can rot the gutter from within if the coating
is impervious. The site recommends instead breathable coatings like
various oils. But I went with the advice on this group (and also the
advice from West Systems tech support) and it's too late...

Stop and think for a minute...automotive finishes stay out in the sun
all day in many places. The autobody supply stores have Bondo
(fabulous stuff), fillers, primers, and the list goes on. A lot of
what you need comes in spray cans if you are compressor and spray gun
deprived. A nice metallic topcoat would reflect a lot of incident UV.
When the sun warms the gutters any trapped moisture will be driven
out. Bottom line, use materials appropriate to the environment. Use
the spar varnish on your yacht.

Joe

All that great looking varnish on yachts has to be constantly
maintained.

For UV protection, you need something opaque. Any good quality house
paint would be superior to spar varnish for this application.


Would "marine" paints be better?


--------------

best way to protect epoxy is with pigmented coatings. Old oil based
varnish had/has natural uv protectors. So does auto clear coat (and one
or two other products) - most clear coatings do not have much UV protection.

Epoxy is the best primer for most coatings. Best to coat epoxy within a
few days of application as epoxies take a week for full cure and coating
applied in that window will have a chemical and mechanical bond.

On old wood gutters I would prime/seal with epoxy then topcoat with enamel.

paul oman
progessive epoxy polymers inc.