Mat unless it is specifically made for epoxy resin should only be used for
polyester resins.
The reason is the binder used to hold the mat together is polyester based
and will not dissolve with epoxy.

"Dan" wrote in message ...
Thanks FR. I have thrown the 6oz material in the trash.
Here is a stupid question, which way do you put down the DB1208, mat side
up, or mat side down against the substrait?

FR wrote:
He said.........

I am using West system epoxy. The material is about 6 mos. old. I am
bonding over fairing putty that was used to level the surface prior to
putting the fiberglass down. It was a clean and course surface. The part
I don't get is that it didn't even stick to itself. I did some repair
work using this epoxy and DB1808 and it is solid as a rock.



You have discovered that the 6 oz finely woven fiber glass that is
commonly sold by "fiberglass supply houses" is terrible when it comes
to adhesion properties. I have found this to be true regardless of the
resin type Epoxy, Vinylester or Polyester.

I think it is attributable to the tightly packed and twisted tows used to
make the material. It does not allow for good saturation.

Next time use a DB1208 and you will get the same results as the DB1808
and save a bit of weight. The glass mat sewn to the double bias strands
offer good saturation and great adhesion and a superior water proofing
layer.

I know of very few "pros" who use this stuff in fiberglass work but for
some reason it seems very popular with do it yourselfers.

In 28 years of fiberglass boat building with five different companies I
have never used this product in a commercially built boat.

My advice is to stay away from it unless your are building model boats.

frp

Thanks John, but the DB1208 and the DB1808 have the mat stitched on so
there is no problem wit the binder. There is no binder. This stuff is
made specifically for epoxy.
Dan

John M wrote:
Mat unless it is specifically made for epoxy resin should only be used for
polyester resins.
The reason is the binder used to hold the mat together is polyester based
and will not dissolve with epoxy.

"Dan" wrote in message ...

Thanks FR. I have thrown the 6oz material in the trash.
Here is a stupid question, which way do you put down the DB1208, mat side
up, or mat side down against the substrait?

FR wrote:

He said.........

I am using West system epoxy. The material is about 6 mos. old. I am
bonding over fairing putty that was used to level the surface prior to
putting the fiberglass down. It was a clean and course surface. The part
I don't get is that it didn't even stick to itself. I did some repair
work using this epoxy and DB1808 and it is solid as a rock.



You have discovered that the 6 oz finely woven fiber glass that is
commonly sold by "fiberglass supply houses" is terrible when it comes
to adhesion properties. I have found this to be true regardless of the
resin type Epoxy, Vinylester or Polyester.

I think it is attributable to the tightly packed and twisted tows used to
make the material. It does not allow for good saturation.

Next time use a DB1208 and you will get the same results as the DB1808
and save a bit of weight. The glass mat sewn to the double bias strands
offer good saturation and great adhesion and a superior water proofing
layer.

I know of very few "pros" who use this stuff in fiberglass work but for
some reason it seems very popular with do it yourselfers.

In 28 years of fiberglass boat building with five different companies I
have never used this product in a commercially built boat.

My advice is to stay away from it unless your are building model boats.

frp

I'm not a peel ply expert, but your problem really sounds like you mixed
the epoxy wrong. If mixed correctly, it should harden as solid as a
rock regardless of what material it is touching (Acetone being the
exception).

Run a few test batches of epoxy to ensure it is curing properly.
Are you using pumps to measure?
Are your ratios correct?

I have never had a batch of West epoxy fail to harden reardless of what
material it is in contact with. Just ask SWMBO, as I am not the neatest
person, and I have glued several of her items to my workbench with the
odd drip of epoxy


Mike McGillivray
Saskatoon

Dan wrote:
What does peel ply look like? Does it look just like 6oz fiberglass cloth?
I laminated two layers of 6oz cloth to my cockpit sole using epoxy. I
laid the fiberglass down dry and lined it up nicely. Then I folded it
back over itself half way. Then I rolled unthickened epoxy over the sole
surface and the laid the fiberglass back over the epoxy and rolled that
down with more epoxy until it was clear. Then I did the other half the
exact same way. I used just enough epoxy to turn the cloth clear but no
extra. Then I laid a second layer of cloth on top of the first layer and
rolled epoxy onto it until it was clear. This is two feet wide by 6 feet
long.
I waited until it was sticky like masking tape. I rolled unthickened
epoxy over the whole surface. I waited until that was sticky and rolled
another coat on it.
after the second coat was sticky, I rolled a 3rd coat on. It was smooth
and shiny. That was two weeks ago. The temperature in the shop was
around 65 or so. I was sweating doing it so it wasn't very cold out. It
was raining outside, but this is in a building.
Today, I was picking at the corner of the glass with my pocket knife. I
was able to lift the corner of the fiberglass. I pushed my knife in
further and was able to lift a big piece of fiberglass. In just 15
minutes, I was able to rip all of the fiberglass off in big pieces. So I
wonder if this guy sold me peel ply instead of fiberglass. I can't
believe that it was a contaminated substrate because, the epoxy should
have stuck somewhere. This was too easy to get up. I pulled it up with
my gloves on and just yanked it up. I can also rip the two courses apart
with ease. What is going on here? What does peel ply look like? Could I
have possibly mistaken peel ply for fiberglass?

Dan wrote:
I agree. The DB170 is great but it sure does stretch out of shape
easy.
If nothing else, the mat helps to keep the shape of the material.

Trying to use mat with epoxy is not only a complete waste of good
epoxy, but it also adds dead weight.

But, if it makes you happy, so be it.

OTOH, mat is a must if using polyester.

Lew

FR wrote:
He said.........

I am using West system epoxy. The material is about 6 mos. old. I am
bonding over fairing putty that was used to level the surface prior to
putting the fiberglass down. It was a clean and course surface. The part
I don't get is that it didn't even stick to itself. I did some repair
work using this epoxy and DB1808 and it is solid as a rock.



You have discovered that the 6 oz finely woven fiber glass that is commonly
sold by "fiberglass supply houses" is terrible when it comes to adhesion
properties. I have found this to be true regardless of the resin type
Epoxy, Vinylester or Polyester.

I think it is attributable to the tightly packed and twisted tows used to
make the material. It does not allow for good saturation.

Next time use a DB1208 and you will get the same results as the DB1808 and
save a bit of weight. The glass mat sewn to the double bias strands offer
good saturation and great adhesion and a superior water proofing layer.

I know of very few "pros" who use this stuff in fiberglass work but for
some reason it seems very popular with do it yourselfers.

In 28 years of fiberglass boat building with five different companies I have
never used this product in a commercially built boat.

My advice is to stay away from it unless your are building model boats.

That's interesting, as I know literally hundreds of people that have
covered wood (S&G or strip) kayaks and canoes with 6 oz. fabric and
epoxy of various brands with zero problems. I've used it in multilayer
kayak repairs with zero problems. I suspect that there's more to this story.

Likewise, however, I did a test with the 6 oz cloth and 17 oz biax. I
laminated two pieces to a piece of plywood side by side using the exact
same epoxy. After 24 hr. curing in the house, I was able to rip the 6 oz
off the wood, but not the biax. I suspect something was wrong with the 6
oz material. I bought new material (10 oz) and I'll try that.


That's interesting, as I know literally hundreds of people that have
covered wood (S&G or strip) kayaks and canoes with 6 oz. fabric and
epoxy of various brands with zero problems. I've used it in multilayer
kayak repairs with zero problems. I suspect that there's more to this
story.

Dan wrote:
Likewise, however, I did a test with the 6 oz cloth and 17 oz biax. I
laminated two pieces to a piece of plywood side by side using the exact
same epoxy. After 24 hr. curing in the house, I was able to rip the 6 oz
off the wood, but not the biax. I suspect something was wrong with the 6
oz material. I bought new material (10 oz) and I'll try that.

Unfortunately, 17 oz. biaxial fabric is WAY too heavy for a lot of
applications.

Also, 24 hours is not adequate cure time for most epoxies before you
torture test them. It's enough to allow you to shape/fair them, but full
curing takes several days at a minimum, unless you're working in
unusually high temps. At low temps, a full cure can take weeks.

Perhaps there was something wrong with the fabric you had, but it's
certainly not a universal problem.

That's interesting, as I know literally hundreds of people that have
covered wood (S&G or strip) kayaks and canoes with 6 oz. fabric and
epoxy of various brands with zero problems. I've used it in multilayer
kayak repairs with zero problems. I suspect that there's more to this
story.