your a moron it should be common sense. you dont need details
explanations to fiqure this one out.

The basic chemical principle is that oxygen greatly slows the rate that
polyester resin cures or "polymerizes" (the molecules link up in long
tangled strings).

The styrene in the resin will dissolve the wax off the paper. As the resin
polymerizes it squeezes the wax back out to the surface forming a thin
film. This film of wax prevents oxygen from reaching the surface so it
cures completely and becomes almost chemically inert. If it is the last
coat that is what you want it do. You can even buy "sanding aids" that are
a solution of wax in styrene to add to the pot while mixing to promote a
hard finish.

However, if you are laying another coat you don't want that. The next coat
will only be mechanically bonded because the polymer strings can't link up
to the strings in the first coat. As polyester is not a very good adhesive
mechanical bonds are not very strong.

OTOH,as long as the resin is exposed to oxygen the molecules at the surface
don't complete the link up so it does not cure completely and remains
chemically active. The next layer of resin will then be able to chemically
link up to the first layer making the whole lay-up a monolithic mass. It
will eventually cure without wax but as long as the next coat goes on within
a few days it will form the chemical bond.

In other words, if you are working with the last coat polyester can (and
should) be exposed to wax. If another coat of polyester will be laid on
top, avoid wax.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

wrote in message
oups.com...
So I don't know who to listen to. Will wax paper leave me with a
unsuitably sticky surface when cured?
Wax paper would be easier for me to work with than saran.

ah ha. Completey different explanation from the first posters.
What does the styrene do? Is it just a functional group of the
polyester? You seem to have taken ochem, perhaps if you care to you
could email me the mechanics and all. I suppose I could look it up but
that would be bothersome.

Polyester resin is a solution of polyester polymers dissolved in styrene.
Polymer molecules are long strings of atoms. When a small amount of a
catalyst like Methyl Ethyl ketone peroxide is added the
it starts a reaction that makes the styrene molecules attach to the sides of
the polyester molecules linking them together in a 3 dimensional matrix.

for example uncured polyester molecules look like this:

A---B---A---B---A---B---A---B

It reacts with the styrene like this:

A---B---A---B---A---B---A---B A---B---A---B---A---B---A---B
| | | |
| | |
S S S S S
S S
| | | |
| | |
A---B---A---B---A---B---A---B A---B---A---B---A---B---A---B

I am no chemist but as I understand it oxygen molecules will loosely bind
with one side of the styrene molecules preventing the double bond. The
styrene molecule prefers the polyester molecule and eventually cast off the
oxygen in favor of the polyester but the process is slowed.

You want those cross linked molecules between coats so that you get a solid
matrix. If the surface is fully cured because a wax film prevents oxygen
getting to it there will be no free styrene molecules for the next layer to
link up to. The new coat will only be mechanically bonded by hooking into
the nooks and crannies on the surface of the cured coat.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

wrote in message
ups.com...
ah ha. Completey different explanation from the first posters.
What does the styrene do? Is it just a functional group of the
polyester? You seem to have taken ochem, perhaps if you care to you
could email me the mechanics and all. I suppose I could look it up but
that would be bothersome.

Well, so much for ASCII art. The lines and Ss are supposed to tie to the
Bs.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Glenn Ashmore" wrote in message
news:tsr3f.607$Kp4.331@lakeread08...
Polyester resin is a solution of polyester polymers dissolved in styrene.
Polymer molecules are long strings of atoms. When a small amount of a
catalyst like Methyl Ethyl ketone peroxide is added the
it starts a reaction that makes the styrene molecules attach to the sides
of the polyester molecules linking them together in a 3 dimensional
matrix.

for example uncured polyester molecules look like this:

A---B---A---B---A---B---A---B

It reacts with the styrene like this:

A---B---A---B---A---B---A---B A---B---A---B---A---B---A---B
| | | | |
| |
S S S S S
S S
| | | | |
| |
A---B---A---B---A---B---A---B
A---B---A---B---A---B---A---B

I am no chemist but as I understand it oxygen molecules will loosely bind
with one side of the styrene molecules preventing the double bond. The
styrene molecule prefers the polyester molecule and eventually cast off
the oxygen in favor of the polyester but the process is slowed.

You want those cross linked molecules between coats so that you get a
solid matrix. If the surface is fully cured because a wax film prevents
oxygen getting to it there will be no free styrene molecules for the next
layer to link up to. The new coat will only be mechanically bonded by
hooking into the nooks and crannies on the surface of the cured coat.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

wrote in message
ups.com...
ah ha. Completey different explanation from the first posters.
What does the styrene do? Is it just a functional group of the
polyester? You seem to have taken ochem, perhaps if you care to you
could email me the mechanics and all. I suppose I could look it up but
that would be bothersome.

all the man wanted to know is if he could mix polyester resin in a wax
cup. was all this explanation necessary? he will have enough trouble
trying to mix it at the proper ratio as it is. then there is the
application....... do i need to know the chemical composition of peanut
butter when I eat it? no.

all the man wanted to know is if he could mix polyester resin in a wax
cup. was all this explanation necessary? he will have enough trouble
trying to mix it at the proper ratio as it is. then there is the
application....... do i need to know the chemical composition of peanut
butter when I eat it? no.

While the subject is more appropriate to r.b.building the question was
posted here so I answered it here. The curing of polyester is a chemical
reaction. The more you know about it the better able you are to take
advantage of its properties.

The original question required a limited explanation of the chemistry to
answer. The follow up question asked specifically what the styrene did. I
believe I answered that and applied it to the original question.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Meye5" wrote in message
oups.com...
all the man wanted to know is if he could mix polyester resin in a wax
cup. was all this explanation necessary? he will have enough trouble
trying to mix it at the proper ratio as it is. then there is the
application....... do i need to know the chemical composition of peanut
butter when I eat it? no.

all you did was confuse the original poster, now he is probably afraid
to ask how to mix it and apply it without being hit with a barrage of
highly technical answers.

huh, I imagined the polyester itself was polymerizing. Thanks for the
post.