Fiberglass Woes

[dick kennedy]

What started out as a simple patch job has turned into a mess. I was out of
fiberglass resin so went out and bought a new quart of Bondo brand
polyester resin. When I got the can I greased the cap with vaseline to keep
it free.

I needed a flat piece to glass over the old furnace ports so the idea was
to put a piece of matt on piece of glass and embed it with resin. Then when
it sets I could put it in place over the holes. Sounds easy doesn't it?

The first try I laid waxed paper on a piece of glass then fiberglass matt &
poured resin over that. I went real light on the hardener on this one.
After two days it's a gooey mess.

The second try I got a new piece of glass, cleaned it with amonia then
applied the matt and resin directly to it. Only this time I used about a
50% excess of hardener. After 24 hours including and hour in the oven it's
still a gooey mess.

Next I poured a little bit of resin in a cup & added a couple of drops of
hardener. It didn't set after an hour so I took another cup with a small
amount and added several drops of hardener. After 12 hours the last cup is
set but only in the part that was fully mixed.

I've been patching things with fiberglass since the seventies doing
everything from snowmobiles to the transom in my boat and have never had a
problem. The only good part here is that I haven't applied any of this goo
to the GMC.

Has anyone else run into similar problems using fiberglass? I don't think
I'n doing anything out of the ordinary but could use a sanity check.

Dick Kennedy
'75 PB

 

[emerystora]

>What started out as a simple patch job has turned into a mess. I was out of
>fiberglass resin so went out and bought a new quart of Bondo brand
>polyester resin. When I got the can I greased the cap with vaseline to keep
>it free.
>
>I needed a flat piece to glass over the old furnace ports so the idea was
>to put a piece of matt on piece of glass and embed it with resin. Then when
>it sets I could put it in place over the holes. Sounds easy doesn't it?
>
>The first try I laid waxed paper on a piece of glass then fiberglass matt &
>poured resin over that. I went real light on the hardener on this one.
>After two days it's a gooey mess.
>
>The second try I got a new piece of glass, cleaned it with amonia then
>applied the matt and resin directly to it. Only this time I used about a
>50% excess of hardener. After 24 hours including and hour in the oven it's
>still a gooey mess.

Dick - it could be that you've just got a bad batch of resin. There
is also a good possibility that by using the vaseline you've
contaminated the resin so that it won't catalyze.

Also, rather than use wax paper which the resin will dissolve and
which also might prevent hardening I would suggest that you use Saran
Wrap which won't contaminate the resin as wax will.

Are you using the right catalyst? Did you buy it with the resin? If
you somehow got an epoxy catalyst it won't work with the polyester
resin. You should use the type and amount of catalyst as specified
on the Bondo can. Using excess hardener will usually cause it to set
up more quickly but the resulting polymer will usually be weaker and
more brittle.

Emery Stora
77 Kingsley
Santa Fe, NM

 

[dan jacquot]

Dick

Same thing happened to me earlier this year. After several tries I bought a
different polyester resin and it worked. I don't know if it has a shelf
life or not but I assume the 1st batch of resin was bad.
Daniel Jacquot
Sheridan WY

- -----Original Message-----
From: Dick Kennedy
To: gmcmotorhome
Date: Wednesday, June 21, 2000 6:53 AM
Subject: GMC: Fiberglass Woes

>What started out as a simple patch job has turned into a mess. I was out of
>fiberglass resin so went out and bought a new quart of Bondo brand
>polyester resin. When I got the can I greased the cap with vaseline to keep
>it free.

>Dick Kennedy
>'75 PB

 

[nate chase]

Dick,
Dunno where you got your products but
I have gotten old stuff from hardware
stores that do just what you're talking
about. Goto a hi volume automotive paint
reseller and get FRESH product (IE both
the resin and hardener). Ask for and
follow the mfgr. directions. It makes a
BIG difference in the final outcome. HTH

Nate 75GB Omaha

>>>
Date: Wed, 21 Jun 2000 07:51:54 -0500
From: Dick Kennedy
Subject: GMC: Fiberglass Woes

What started out as a simple patch job
has turned into a mess. I was out of
fiberglass resin so went out and bought
a new quart of Bondo brand
polyester resin. When I got the can I
greased the cap with vaseline to keep
it free.

I needed a flat piece to glass over the
old furnace ports so the idea was
to put a piece of matt on piece of glass
and embed it with resin. Then when
it sets I could put it in place over the
holes. Sounds easy doesn't it?

The first try I laid waxed paper on a
piece of glass then fiberglass matt &
poured resin over that. I went real
light on the hardener on this one.
After two days it's a gooey mess.

The second try I got a new piece of
glass, cleaned it with amonia then
applied the matt and resin directly to
it. Only this time I used about a
50% excess of hardener. After 24 hours
including and hour in the oven it's
still a gooey mess.

Next I poured a little bit of resin in a
cup & added a couple of drops of
hardener. It didn't set after an hour so
I took another cup with a small
amount and added several drops of
hardener. After 12 hours the last cup is
set but only in the part that was fully
mixed.

I've been patching things with
fiberglass since the seventies doing
everything from snowmobiles to the
transom in my boat and have never had a
problem. The only good part here is that
I haven't applied any of this goo
to the GMC.

Has anyone else run into similar
problems using fiberglass? I don't think
I'n doing anything out of the ordinary
but could use a sanity check.

Dick Kennedy
'75 PB

 

[antnip]

I have spent a lot of time around boats, and breathed a lot of resin fumes,
so my memory may be foggy, but as others have suggested, you either have
some ancient materials, or the wrong catalyst/hardener.

When I was younger a friend of mine attempted to glass over a plywood boat
and ran into the same problem. What a mess!. Be glad you discovered your
problem before you put resin to coach!

Tony

- ----- Original Message -----
From: Dick Kennedy
To:
Sent: Wednesday, June 21, 2000 8:51 AM
Subject: GMC: Fiberglass Woes

> What started out as a simple patch job has turned into a mess. I was out
of
> fiberglass resin so went out and bought a new quart of Bondo brand
> polyester resin. When I got the can I greased the cap with vaseline to
keep
> it free.
>
> I needed a flat piece to glass over the old furnace ports so the idea was
> to put a piece of matt on piece of glass and embed it with resin. Then
when
> it sets I could put it in place over the holes. Sounds easy doesn't it?
>
> The first try I laid waxed paper on a piece of glass then fiberglass matt
&
> poured resin over that. I went real light on the hardener on this one.
> After two days it's a gooey mess.
>
> The second try I got a new piece of glass, cleaned it with amonia then
> applied the matt and resin directly to it. Only this time I used about a
> 50% excess of hardener. After 24 hours including and hour in the oven it's
> still a gooey mess.
>
> Next I poured a little bit of resin in a cup & added a couple of drops of
> hardener. It didn't set after an hour so I took another cup with a small
> amount and added several drops of hardener. After 12 hours the last cup is
> set but only in the part that was fully mixed.
>
> I've been patching things with fiberglass since the seventies doing
> everything from snowmobiles to the transom in my boat and have never had a
> problem. The only good part here is that I haven't applied any of this goo
> to the GMC.
>
> Has anyone else run into similar problems using fiberglass? I don't think
> I'n doing anything out of the ordinary but could use a sanity check.
>
> Dick Kennedy
> '75 PB
>

 

[richard dobson]

What started out as a simple patch job has turned into a mess. I was out
of
fiberglass resin so went out and bought a new quart of Bondo
brand
Dick,I have never been a fan of Bondo brand anything. Evercoat is
usually available in hardware stores in the marine section or go to a
marine store. I trust this brand of polyester resin. Usually 10 drops of
MEKP hardner to 1 oz. of resin is a good starting place. Your method of
fabrication sounds OK. BTW WARNING a lot of people out there may not
realize that MEKP is very dangerous to the eyes. One splashed drop will
for certain blind you even if eyes are flushed within 30 sec. Use eye
protection while mixing.