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. I need to
figure out what this fiberglass material is. I'm going to do a test
laminate on wood today to see how it adheres. I ruled out contamination
because I can peel both layers apart. That's what's confusing.

It didn't bond well to the fairing putty, but it didn't bond well to the
original fiberglass either. Hmmmm...
Thanks for the reply's,
Dan

Ystay wrote:
Sounds like a problem with the epoxy, not the glass. What you're using is
definitely not peel ply. What brand of epoxy were you using? Was it
formulated as a laminating epoxy rather than a "glueing" epoxy? Seems like
you did everything right. I can sort of understand if it didn't stick to
the substrate but it MUST have at least stuck to itself. Hmmmm....

Arnold

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 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

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

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.

snip

DB1208 is great for polyester but the mat does nothing but add
unnecessary weight when using epoxy.

Personally, I like DB170 for epoxy.

Lew

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.

Lew Hodgett wrote:

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.

snip

DB1208 is great for polyester but the mat does nothing but add
unnecessary weight when using epoxy.

Personally, I like DB170 for epoxy.

Lew

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.