Re: Latex Sealer or Primer over Expoxy?
Stefan,
I think the problem with recounting our own experience is that
products vary from market to market.
FWIW, my recent experience of painting a stitch and glue boat is as
follows: After construction in the usual way and a certain amount of
filling with epoxy filler then sanding, I brushed on a coat of low-
sheen exterior acrylic paint. This particular brand is recommended
to be used without a sealer, primer or undercoat. The ply had not
been epoxy coated, so the paint went over bare ply (marine ply, from
Malaysian tropical hardwood) except over the seams, where it went
over over the epoxy.
When I wet-sanded the first coat, some of it came off where it had
been applied to epoxy that had not been sanded previously. After wet-
sanding I applied a touch-up coat over the bare areas then one more
overall coat.
The result seems to be durable and it's easy to touch up the areas
that get rubbed or scraped in use. It's more workboat finish than
yacht finish.
Once the epoxy is no longer sticky, I'm not sure how you could judge
whether it is "green" or "cured" or whatever and I don't think it
matters much. Just make sure the surface has all been sanded before
you paint.
The exterior acrylic paint is (of course) meant to be used on
surfaces exposed to the weather. Apart from being more durable than
interior acrylic, it seems that it cures ("dries") much more quickly
if exposed to UV light. So, if you are painting inside a building
(or inside an enclosed hull) you'd probably want to allow two or
three days (perhaps longer) before sanding the first coat or before
launching after the last coat.
Hope this helps.
Howard
--- Inbolger@yahoogroups.com, "Stefan Probst" <stefan.probst@o...>
wrote:
I think the problem with recounting our own experience is that
products vary from market to market.
FWIW, my recent experience of painting a stitch and glue boat is as
follows: After construction in the usual way and a certain amount of
filling with epoxy filler then sanding, I brushed on a coat of low-
sheen exterior acrylic paint. This particular brand is recommended
to be used without a sealer, primer or undercoat. The ply had not
been epoxy coated, so the paint went over bare ply (marine ply, from
Malaysian tropical hardwood) except over the seams, where it went
over over the epoxy.
When I wet-sanded the first coat, some of it came off where it had
been applied to epoxy that had not been sanded previously. After wet-
sanding I applied a touch-up coat over the bare areas then one more
overall coat.
The result seems to be durable and it's easy to touch up the areas
that get rubbed or scraped in use. It's more workboat finish than
yacht finish.
Once the epoxy is no longer sticky, I'm not sure how you could judge
whether it is "green" or "cured" or whatever and I don't think it
matters much. Just make sure the surface has all been sanded before
you paint.
The exterior acrylic paint is (of course) meant to be used on
surfaces exposed to the weather. Apart from being more durable than
interior acrylic, it seems that it cures ("dries") much more quickly
if exposed to UV light. So, if you are painting inside a building
(or inside an enclosed hull) you'd probably want to allow two or
three days (perhaps longer) before sanding the first coat or before
launching after the last coat.
Hope this helps.
Howard
--- Inbolger@yahoogroups.com, "Stefan Probst" <stefan.probst@o...>
wrote:
> What experiences do others have?
--- "Joe Tribulato" <scsbmsjoe@y...> wrote:
look again where. I like the idea of avoiding to scrub the boat. And
since I am not into a picture-perfect glossy finish, I think I can
avoid the sanding - except a few spots.
job, or whether I just should paint without a primer.
to 36°C (85F to 95F and more). Night time around 25° (77F). The
manufacturer of the Epoxy gives 5h potlife, 1-2h for repainting, 3-5h
for touch dry, and 15-22h curing. I think it doesn't take "a week or
two" to cure, but "a day or two".
What experiences to others have?
Thanks,
Stefan
> Would strongly advise not painting on green epoxy.This is not my own idea, but I read it somewhere a while ago. Had to
look again where. I like the idea of avoiding to scrub the boat. And
since I am not into a picture-perfect glossy finish, I think I can
avoid the sanding - except a few spots.
> No sealer is needed over epoxy.Question is, if I don't find a primer, whether a sealer would do the
job, or whether I just should paint without a primer.
> The usual drill is allow it to cure a week or two.Daytime temperatures are in the summer months permanently between 30°C
to 36°C (85F to 95F and more). Night time around 25° (77F). The
manufacturer of the Epoxy gives 5h potlife, 1-2h for repainting, 3-5h
for touch dry, and 15-22h curing. I think it doesn't take "a week or
two" to cure, but "a day or two".
> The primer also aids adhesion of the finish coat.I think that was the reason to paint onto the green expoxy.
What experiences to others have?
Thanks,
Stefan
Stefan
Would strongly advise not painting on green epoxy. No sealer is needed
over epoxy. The usual drill is allow it to cure a week or two. Scrub
with an abrasive pad and soapy water. Rinse and dry. Sand. When the
smoothness meets your standards remove dust and apply primer. Sand
lightly. Prime again so it is fully covered. This will leave an even
color over which to apply the finish. I usually need two color coats
at least. The primer also aids adhesion of the finish coat.
Would strongly advise not painting on green epoxy. No sealer is needed
over epoxy. The usual drill is allow it to cure a week or two. Scrub
with an abrasive pad and soapy water. Rinse and dry. Sand. When the
smoothness meets your standards remove dust and apply primer. Sand
lightly. Prime again so it is fully covered. This will leave an even
color over which to apply the finish. I usually need two color coats
at least. The primer also aids adhesion of the finish coat.
--- Inbolger@yahoogroups.com, "Stefan Probst" <stefan.probst@o...> wrote:
> Looking for experts ...
>
> I read that it is good to use a primer as first layer...
>
> I plan to cover the ply with at least two layers of Epoxy (and one FG
> at the bottom) and then with two to three layers of latex-based paint.
> When I checked last weekend in a shop where they sell the latex paint,
> they didn't have a primer, but a "sealer" to seal the wall/bricks from
> humidity.
>
> Should I use such a sealer? Does it make any sense? Or should I just
> paint the first layer of paint on the Epoxy (while it is still "green")?
>
> Thanks for any advice,
>
> Stefan
--- Inbolger@yahoogroups.com, "Stefan Probst" <stefan.probst@o...>
wrote:
I'm not an expert, but...
First, check with the epoxy manufacturer if possible. Different
formulations have different characteristics, and the manufacturer is
going to be in the best postion to say how to finish their product.
What has worked for me using RAKA epoxy is: lay the FG in unthickened
epoxy on bare wood (I prefer to wet out the wood first, but the cloth
can be laid on dry as long as you work the epoxy in well). This first
coat should be as thin as you can make it while still getting a full
wet out of the cloth and wood. Follow with a second coat of epoxy
thickened with silica, and a third coat with silica and microballons.
The epoxy coats should be done while the preceding coat is still
green - usually within 24 hours is OK. Then let the epoxy fully cure
for a week or two. Scrub with soapy water and a scrubbing pad, then
rinse well. Sand until you are happy with the finish. I found 60 grit
was fine for finishing. Wipe away sanding dust with a cloth moistened
with water or mineral spirits. To get to your actual question - I
have used latex primer from a paint store under latex paint, works
fine (I'm not sure about the sealer, but if it is meant to go under
latex and is not a thick masonry sealer it is probably OK). I've also
used a one part polyurethane enamel (porch and deck paint) without a
primer over epoxy with success. The enamel does not cost much more
than the latex and produces a better finish than latex, IMO.
Bill
wrote:
> Looking for experts ...still "green")?
> Should I use such a sealer? Does it make any sense? Or should I just
> paint the first layer of paint on the Epoxy (while it is
I'm not an expert, but...
First, check with the epoxy manufacturer if possible. Different
formulations have different characteristics, and the manufacturer is
going to be in the best postion to say how to finish their product.
What has worked for me using RAKA epoxy is: lay the FG in unthickened
epoxy on bare wood (I prefer to wet out the wood first, but the cloth
can be laid on dry as long as you work the epoxy in well). This first
coat should be as thin as you can make it while still getting a full
wet out of the cloth and wood. Follow with a second coat of epoxy
thickened with silica, and a third coat with silica and microballons.
The epoxy coats should be done while the preceding coat is still
green - usually within 24 hours is OK. Then let the epoxy fully cure
for a week or two. Scrub with soapy water and a scrubbing pad, then
rinse well. Sand until you are happy with the finish. I found 60 grit
was fine for finishing. Wipe away sanding dust with a cloth moistened
with water or mineral spirits. To get to your actual question - I
have used latex primer from a paint store under latex paint, works
fine (I'm not sure about the sealer, but if it is meant to go under
latex and is not a thick masonry sealer it is probably OK). I've also
used a one part polyurethane enamel (porch and deck paint) without a
primer over epoxy with success. The enamel does not cost much more
than the latex and produces a better finish than latex, IMO.
Bill
--- Inbolger@yahoogroups.com, "Stefan Probst" <stefan.probst@o...>
wrote:
I'm no expert. I followed the advice of experts. This only works in
North America. It only works on bare wood. Smith's Clear Penetrating
Epoxy Sealer, one coat. Kirby's Marine Enamel applied over the
Smith's C.P.E.S. 24-72 hours later or as soon as the sealer is tack
free. Painting over the sealer the minute it is tack free is critical
to the whole job. If the paint goes on while the sealer is still
chemically active and "glues" the paint to the boat. 2-4 coats of
Kirby's paint thinned per George Kirby's instrictions over the phone.
Estimated lifespan - 5+ years.
Wayne
In the Swamp.
wrote:
> Should I use such a sealer? Does it make any sense? Or should I juststill "green")?
> paint the first layer of paint on the Epoxy (while it is
>Or something a little different.
> Thanks for any advice,
>
> Stefan
I'm no expert. I followed the advice of experts. This only works in
North America. It only works on bare wood. Smith's Clear Penetrating
Epoxy Sealer, one coat. Kirby's Marine Enamel applied over the
Smith's C.P.E.S. 24-72 hours later or as soon as the sealer is tack
free. Painting over the sealer the minute it is tack free is critical
to the whole job. If the paint goes on while the sealer is still
chemically active and "glues" the paint to the boat. 2-4 coats of
Kirby's paint thinned per George Kirby's instrictions over the phone.
Estimated lifespan - 5+ years.
Wayne
In the Swamp.
Looking for experts ...
I read that it is good to use a primer as first layer...
I plan to cover the ply with at least two layers of Epoxy (and one FG
at the bottom) and then with two to three layers of latex-based paint.
When I checked last weekend in a shop where they sell the latex paint,
they didn't have a primer, but a "sealer" to seal the wall/bricks from
humidity.
Should I use such a sealer? Does it make any sense? Or should I just
paint the first layer of paint on the Epoxy (while it is still "green")?
Thanks for any advice,
Stefan
I read that it is good to use a primer as first layer...
I plan to cover the ply with at least two layers of Epoxy (and one FG
at the bottom) and then with two to three layers of latex-based paint.
When I checked last weekend in a shop where they sell the latex paint,
they didn't have a primer, but a "sealer" to seal the wall/bricks from
humidity.
Should I use such a sealer? Does it make any sense? Or should I just
paint the first layer of paint on the Epoxy (while it is still "green")?
Thanks for any advice,
Stefan