Has anyone tried or know what would happen if you applied a
polyurethane product over epoxy when the epoxy was still tacky. Would
the adhesion be better? Would it intefere with the cure of the epoxy?
What about a latex primer over sticky epoxy? Anyone try anything like
that to try and get a better adhesion to the epoxy?

TIA,

Bob

On Sat, 23 Jun 2007 06:23:54 -0700, wrote:

Has anyone tried or know what would happen if you applied a
polyurethane product over epoxy when the epoxy was still tacky. Would
the adhesion be better? Would it intefere with the cure of the epoxy?
What about a latex primer over sticky epoxy? Anyone try anything like
that to try and get a better adhesion to the epoxy?

TIA,

Bob

I once tried that trick with coal-tar epoxy and copper anti-fouling.
Cleaned the propeller real well and applied coal-tar epoxy. Waited
until it got tacky and slathered on the copper based paint. The next
trip most of the paint came off, just like it always does.

As far as I can tell there is no problem in making paint stick to
epoxy.I usually make sure that any blush is cleaned off the epoxy and
then fill, fair and prime with epoxy based materials and apply a top
coat of two part polyurethane. My sloop is going on ten years now and
still looks pretty good.


Bruce in Bangkok
(brucepaigeatgmaildotcom)

--
Posted via a free Usenet account from http://www.teranews.com

schreef in news:1182605034.890782.50700
@m36g2000hse.googlegroups.com

Has anyone tried or know what would happen if you applied a
polyurethane product over epoxy when the epoxy was still tacky. Would
the adhesion be better? Would it intefere with the cure of the epoxy?
What about a latex primer over sticky epoxy? Anyone try anything like
that to try and get a better adhesion to the epoxy?

I have never tried it, for the reason that my local vendor warns against
doing this. They even claim that is wise not to paint epoxy before it is
fully (and I mean FULLY) cured. That can take up to a week, depending on
temperature and formulation of the epoxy.

Adding another coat, before the previous coat is not fully cured, works
great for the adhesion between coats of epoxy, but not between epoxy and
something else.

--
Lodewijk

On Jun 23, 6:26 pm, Lodewijk Stegman
wrote:
schreef in news:1182605034.890782.50700
@m36g2000hse.googlegroups.com

Has anyone tried or know what would happen if you applied a
polyurethane product over epoxy when the epoxy was still tacky. Would
the adhesion be better? Would it intefere with the cure of the epoxy?
What about a latex primer over sticky epoxy? Anyone try anything like
that to try and get a better adhesion to the epoxy?

I have never tried it, for the reason that my local vendor warns against
doing this. They even claim that is wise not to paint epoxy before it is
fully (and I mean FULLY) cured. That can take up to a week, depending on
temperature and formulation of the epoxy.

Adding another coat, before the previous coat is not fully cured, works
great for the adhesion between coats of epoxy, but not between epoxy and
something else.

--
Lodewijk

I laid some marine enamel down once on tacky epoxy, forget the brand,
but it made a great bond. But note it was pure luck because in other
attempts to do this in uncontrolled environment led to major peeling.
I think the best way to go is "traditional", washing the surface,
roughing it up, and depending on a mechanical bond. Just my opinion.

wrote:

On Jun 23, 6:26 pm, Lodewijk Stegman
wrote:


schreef in news:1182605034.890782.50700




Has anyone tried or know what would happen if you applied a
polyurethane product over epoxy when the epoxy was still tacky. Would
the adhesion be better? Would it intefere with the cure of the epoxy?
What about a latex primer over sticky epoxy? Anyone try anything like
that to try and get a better adhesion to the epoxy?


I have never tried it, for the reason that my local vendor warns against
doing this. They even claim that is wise not to paint epoxy before it is
fully (and I mean FULLY) cured. That can take up to a week, depending on
temperature and formulation of the epoxy.


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



We have put wet latex over wet epoxy (epoxy that was mixed minutes
before). If it is a top epoxy you get a perfect finish, of course you
cannot brush the latex paint on....

folks usually wait a bit past tacky (but still soft enough to put your
thumbnail into the epoxy).

Actually epoxies take about a week to fully cure, so if you have
topcoated epoxy in less than a week, you've actually painted over not
fully cured epoxy anyway. At least in theory, the coating fuse and you
get a chemical as well as a mechanical bond.

paul oman
progressive epoxy polymers inc
www.epoxyproducts.com/marine.html

Paul Oman wrote:

We have put wet latex over wet epoxy (epoxy that was mixed minutes
before). If it is a top epoxy you get a perfect finish, of course you
cannot brush the latex paint on....

folks usually wait a bit past tacky (but still soft enough to put your
thumbnail into the epoxy).

Actually epoxies take about a week to fully cure, so if you have
topcoated epoxy in less than a week, you've actually painted over not
fully cured epoxy anyway. At least in theory, the coating fuse and you
get a chemical as well as a mechanical bond.


provided, of course, that no surface blush has developed...

cavelamb himself wrote:

Paul Oman wrote:


We have put wet latex over wet epoxy (epoxy that was mixed minutes
before). If it is a top epoxy you get a perfect finish, of course
you cannot brush the latex paint on....

folks usually wait a bit past tacky (but still soft enough to put
your thumbnail into the epoxy).

Actually epoxies take about a week to fully cure, so if you have
topcoated epoxy in less than a week, you've actually painted over not
fully cured epoxy anyway. At least in theory, the coating fuse and
you get a chemical as well as a mechanical bond.


provided, of course, that no surface blush has developed...

--- that's true, but the good epoxies generally don't blush --- paul

On Jun 23, 8:23 am, wrote:
Has anyone tried or know what would happen if you applied a
polyurethane product over epoxy when the epoxy was still tacky. Would
the adhesion be better? Would it intefere with the cure of the epoxy?
What about a latex primer over sticky epoxy? Anyone try anything like
that to try and get a better adhesion to the epoxy?

TIA,

Bob

Thanks guys. I guess I'll let it cure first. I was hoping to avoid
sanding because the sanding won't be the easiest. It's nott a nice
flat surface. It's all fillet sanding and the fillets aren't the
smoothest..

On Jun 28, 7:49 am, wrote:
On Jun 23, 8:23 am, wrote:

Has anyone tried or know what would happen if you applied a
polyurethane product over epoxy when the epoxy was still tacky. Would
the adhesion be better? Would it intefere with the cure of the epoxy?
What about a latex primer over sticky epoxy? Anyone try anything like
that to try and get a better adhesion to the epoxy?

TIA,

Bob

Thanks guys. I guess I'll let it cure first. I was hoping to avoid
sanding because the sanding won't be the easiest. It's nott a nice
flat surface. It's all fillet sanding and the fillets aren't the
smoothest..

One thing I have found you can do is scrape nearly cured epoxy with a
dutch scraper, or even a wood rasp if you need to take down more
material. Of course, if you are painting opaque, you can use a fairing
compound to fill in areas which makes for easier sanding. Good luck,
keep the elbow brace handy...