Re: My First Time With Polyester Resin
Right you are, and I stand corrected. I looked at the little tube and
there was that P right at the end of MEK. Hope I didn't confuse
anyone.
Don't know about the other stuff, have never tried it.
Steve.
"BTW, MEK won't catalyse resin. MEKP will. THey are two very
different
chemicals! MEK is a solvent and MEKP is reactive enough to be a real
bad eye hazard."
there was that P right at the end of MEK. Hope I didn't confuse
anyone.
Don't know about the other stuff, have never tried it.
Steve.
"BTW, MEK won't catalyse resin. MEKP will. THey are two very
different
chemicals! MEK is a solvent and MEKP is reactive enough to be a real
bad eye hazard."
I wonder if vinylester or whatever you call it is a bit less brittle,
maybe even stick better? More water resistant? Or how about isopthalic
(sp?), for that matter? I hope the resin under discussion is NOT the
type with wax in it.
BTW, MEK won't catalyse resin. MEKP will. THey are two very different
chemicals! MEK is a solvent and MEKP is reactive enough to be a real
bad eye hazard.
http://johnrsweet.com/mekp.html
http://www.temarry.com/MSDS/Methyl_Ethyl_Ketone_msds.htm
maybe even stick better? More water resistant? Or how about isopthalic
(sp?), for that matter? I hope the resin under discussion is NOT the
type with wax in it.
BTW, MEK won't catalyse resin. MEKP will. THey are two very different
chemicals! MEK is a solvent and MEKP is reactive enough to be a real
bad eye hazard.
http://johnrsweet.com/mekp.html
http://www.temarry.com/MSDS/Methyl_Ethyl_Ketone_msds.htm
--- In bolger@y..., "Steven Lewis" <numbaoneman@b...> wrote:
> Two things come to mind. 1: Polyester is more brittle, so if it is
> subject to much flex it might start cracking, I say this from
> experience. 2: Polyester isn't waterproof
snip
> of unthinned resin for strength. Thin after adding the MEK and mix
> very well, but quickly.
> It sounds like you have you have some experience and if I am being
> redundant, my appologies, just wanted to pass on a little experience
> of my own.
>
>
> Steve.
> --- In bolger@y..., teakdeck@a... wrote:
> > Bolgeramos,
snip
> >
> > Mike Masten
Two things come to mind. 1: Polyester is more brittle, so if it is
subject to much flex it might start cracking, I say this from
experience. 2: Polyester isn't waterproof (also from experience) and
needs to be varnished or painted to provide a decent moisture
barrier. Be very careful if using for fillets, as it isn't a real
good glue. It should work if you do a 4 step process of 1)wet the
joint with resin, 2)fillet, 3)tape and 4) wet out the tape fully.
This should all be done in one shot. Make your fillets larger than
you would with epoxy too, to make them stronger (remember its
brittle). Make sure you scuff up the wood where you will be using
Poly. Use 80 grit and go with, cross and diagonal to the grain. This
should allow better penetration of the resin into the wood. You can
also thin the first coat with acetone (by about 10-15%) to help
penetration, but only on the first coat and it needs subsequent coats
of unthinned resin for strength. Thin after adding the MEK and mix
very well, but quickly.
It sounds like you have you have some experience and if I am being
redundant, my appologies, just wanted to pass on a little experience
of my own.
Steve.
subject to much flex it might start cracking, I say this from
experience. 2: Polyester isn't waterproof (also from experience) and
needs to be varnished or painted to provide a decent moisture
barrier. Be very careful if using for fillets, as it isn't a real
good glue. It should work if you do a 4 step process of 1)wet the
joint with resin, 2)fillet, 3)tape and 4) wet out the tape fully.
This should all be done in one shot. Make your fillets larger than
you would with epoxy too, to make them stronger (remember its
brittle). Make sure you scuff up the wood where you will be using
Poly. Use 80 grit and go with, cross and diagonal to the grain. This
should allow better penetration of the resin into the wood. You can
also thin the first coat with acetone (by about 10-15%) to help
penetration, but only on the first coat and it needs subsequent coats
of unthinned resin for strength. Thin after adding the MEK and mix
very well, but quickly.
It sounds like you have you have some experience and if I am being
redundant, my appologies, just wanted to pass on a little experience
of my own.
Steve.
--- In bolger@y..., teakdeck@a... wrote:
> Bolgeramos,
>
> Okay, not really my first time. I tried it once before but I had
problems
> with the application. This time was much better.
>
> I am building a little boat, a two sheeter really, which Is in part
a
> recovery of an old project which has laid out in the backyard for
at least a
> year.
>
> Anyway, I used external chines and glued the bottom on. Next, I
taped the
> bottom seam with polyester resin and fiberglass tape. I laid out
the tape and
> then wetted it with resin. Once tacky, I applied a second coat. I
let it dry,
> took down the bumps and roughed up the rest with 60 grit and
applied a third
> coat. Beautiful. I can't imagine this ever peeling.
>
> I should mention I'm allergic to epoxy, so having some success with
polyester
> opens up some new designs for me. Plus, this stuff really is a lot
cheaper
> than epoxy. And you can effect the cure time by adding more or less
fixer.
> Next, I'll have to try making a fillet mixture.
>
> Mike Masten
Bolgeramos,
Okay, not really my first time. I tried it once before but I had problems
with the application. This time was much better.
I am building a little boat, a two sheeter really, which Is in part a
recovery of an old project which has laid out in the backyard for at least a
year.
Anyway, I used external chines and glued the bottom on. Next, I taped the
bottom seam with polyester resin and fiberglass tape. I laid out the tape and
then wetted it with resin. Once tacky, I applied a second coat. I let it dry,
took down the bumps and roughed up the rest with 60 grit and applied a third
coat. Beautiful. I can't imagine this ever peeling.
I should mention I'm allergic to epoxy, so having some success with polyester
opens up some new designs for me. Plus, this stuff really is a lot cheaper
than epoxy. And you can effect the cure time by adding more or less fixer.
Next, I'll have to try making a fillet mixture.
Mike Masten
Okay, not really my first time. I tried it once before but I had problems
with the application. This time was much better.
I am building a little boat, a two sheeter really, which Is in part a
recovery of an old project which has laid out in the backyard for at least a
year.
Anyway, I used external chines and glued the bottom on. Next, I taped the
bottom seam with polyester resin and fiberglass tape. I laid out the tape and
then wetted it with resin. Once tacky, I applied a second coat. I let it dry,
took down the bumps and roughed up the rest with 60 grit and applied a third
coat. Beautiful. I can't imagine this ever peeling.
I should mention I'm allergic to epoxy, so having some success with polyester
opens up some new designs for me. Plus, this stuff really is a lot cheaper
than epoxy. And you can effect the cure time by adding more or less fixer.
Next, I'll have to try making a fillet mixture.
Mike Masten