Seems like with polyester resin, one needs to mix some wax with the final coat
so air cannot get to the laminating coats and they will harden fully.

Does the same thing hold with epoxy? If not a finish coat, is a layer of paint
needed to make it harden fully?

My agenda is I'm covering a seam. I could finish-coat it if such a thing is
available using epoxy... but I don't want to paint it because I want the option
of easily checking what's going on underneath.

If UV degradation is an issue, my intent would be to cover the area with wide
electrical tape - or some other tape that is easily removed/replaced.
--
PeteCresswell

(PeteCresswell) wrote:
Seems like with polyester resin, one needs to mix some wax with the final coat
so air cannot get to the laminating coats and they will harden fully.

Does the same thing hold with epoxy? If not a finish coat, is a layer of paint
needed to make it harden fully?

My agenda is I'm covering a seam. I could finish-coat it if such a thing is
available using epoxy... but I don't want to paint it because I want the option
of easily checking what's going on underneath.

If UV degradation is an issue, my intent would be to cover the area with wide
electrical tape - or some other tape that is easily removed/replaced.

UV degredation IS an issue with epoxy, but it cures fine without coating
it with anything.

No wax or other barrier is needed for epoxy to cure.
Some epoxies under some conditions will, in curing, exude a water-soluble
coating called 'amine blush' which needs to be washed off before re-coating
or painting.
Sanding is a good idea before recoating or painting.
UV will degrade epoxy over time. I think that cocering with tape will be
adequate protection.


"(PeteCresswell)" wrote in message
...
Seems like with polyester resin, one needs to mix some wax with the final
coat
so air cannot get to the laminating coats and they will harden fully.

Does the same thing hold with epoxy? If not a finish coat, is a layer of
paint
needed to make it harden fully?

My agenda is I'm covering a seam. I could finish-coat it if such a thing
is
available using epoxy... but I don't want to paint it because I want the
option
of easily checking what's going on underneath.

If UV degradation is an issue, my intent would be to cover the area with
wide
electrical tape - or some other tape that is easily removed/replaced.
--
PeteCresswell

(PeteCresswell) writes:

If UV degradation is an issue, my intent would be to cover the area
with wide electrical tape - or some other tape that is easily
removed/replaced.

Suggest you use aluminum duct tape from the home improvement store.
Absolute UV barrier, durable adhesive, easily removed with a little heat
and solvent.

(PeteCresswell) writes:

If UV degradation is an issue, my intent would be to cover the area
with wide electrical tape - or some other tape that is easily
removed/replaced.


Hmm, why not just use the 207-hardener (has UV-filters in it), and/or a
lacquer with uv-filters in it?

If you want it to be coloured, like it would with a non-see-through
tape, why not just paint it?

As a small "PS", lacquer on top of epoxy holds much longer than lacquer
on it's own, presumably because of the stabler base that the epoxy
makes (it's a sort of plastics). Paint is the same, and just to pee
some people off, it's an old folk's tale that the more high gloss a
finish is, the better the wood (or whatever) underneath is protected.
The reasoning behind the tale is because of the sheen/reflection that
occurs when the angle of the lightsource (the sun) is very low.
Problem is, it's when the sun shines straight onto the lacquer that
most radiation is getting through, and a high gloss finish - i.e. a see
through, glasslike, finish will make even more UV through. So, the more
matt finish, the better the protection - all theway thhrough to
painting it, or covering it by other means.

Further, be aware that around 100-120 centigrades, epoxy looses it's
strength, so better paint it light (er) in colour.

Anyways, that was my two cents ...

Per Dane:
Hmm, why not just use the 207-hardener (has UV-filters in it), and/or a
lacquer with uv-filters in it?

If you want it to be coloured, like it would with a non-see-through
tape, why not just paint it?

I want to be able to check up on a suspect area underneath it without sanding
off paint/gel coat.

Actually, the alternative hardener is sounding pretty good.
--
PeteCresswell

(PeteCresswell) wrote:
Per Dane:

Hmm, why not just use the 207-hardener (has UV-filters in it), and/or a
lacquer with uv-filters in it?

If you want it to be coloured, like it would with a non-see-through
tape, why not just paint it?


I want to be able to check up on a suspect area underneath it without sanding
off paint/gel coat.

Actually, the alternative hardener is sounding pretty good.

I wouldn't trust a hardener to provide adequate long-term protection.
You're better off to have an opaque layer of some sort over the epoxy.

Just be aware that there is an additional, hazardous material shipping
charge for shipping 207. I think I paid somewhere around $25 for a
quart of it. If you can find it locally it's worth doing.

WEST 207 does not hold up all that much better than the other WEST
hardeners. Its more important feature is that it's a bit clearer. It's
expensive and really only cost-justified for fancy light-color work like
strip canoes. Any epoxy needs a UV resistent coating to protect it. The
good marine varnishes are a practical way to do this. I am not aware of any
UV tolerant lacquers .


"Dane" wrote in message
oups.com...
(PeteCresswell) writes:

If UV degradation is an issue, my intent would be to cover the area
with wide electrical tape - or some other tape that is easily
removed/replaced.


Hmm, why not just use the 207-hardener (has UV-filters in it), and/or a
lacquer with uv-filters in it?

If you want it to be coloured, like it would with a non-see-through
tape, why not just paint it?

As a small "PS", lacquer on top of epoxy holds much longer than lacquer
on it's own, presumably because of the stabler base that the epoxy
makes (it's a sort of plastics). Paint is the same, and just to pee
some people off, it's an old folk's tale that the more high gloss a
finish is, the better the wood (or whatever) underneath is protected.
The reasoning behind the tale is because of the sheen/reflection that
occurs when the angle of the lightsource (the sun) is very low.
Problem is, it's when the sun shines straight onto the lacquer that
most radiation is getting through, and a high gloss finish - i.e. a see
through, glasslike, finish will make even more UV through. So, the more
matt finish, the better the protection - all theway thhrough to
painting it, or covering it by other means.

Further, be aware that around 100-120 centigrades, epoxy looses it's
strength, so better paint it light (er) in colour.

Anyways, that was my two cents ...

I completely forgot to mention that all that is needed in order to make
epoxy harden is heat. between 16 and 21 degrees celcius. The great
thing is, if you make it in cold climates, it will just "wait", and
harden when heated. No solvents, just a chemical reaction, using heat
as a catalyst.