Re: [bolger] A call for chemists
The unlike polyester resins, the hardener in epoxy is NOT a catalyst. It is
instead a cross-linking agent that hooks the chains of pre-polymerized resin
together. Heating it up or slathering more hardener on top will not create
the necessary cross-links to make the solid and strong material that we all
know and love. Clean it off and start over.
instead a cross-linking agent that hooks the chains of pre-polymerized resin
together. Heating it up or slathering more hardener on top will not create
the necessary cross-links to make the solid and strong material that we all
know and love. Clean it off and start over.
----- Original Message -----
From: "Clyde Wisner" <clydewis@...>
To: <bolger@yahoogroups.com>
Sent: Saturday, May 28, 2005 10:12 AM
Subject: Re: [bolger] A call for chemists
| A little heat might ause it to kick over a little quicker, but not a lot
| of heat as epoxy is degraded by high heat. Also not petrol based heat
| like kerosine as the fumes can effect epoxy. Clyde
|
|
| Jack&Lois wrote:
|
| > ...or anyone who has insights into sticky epoxy issues. A good friend
who
| > has started building his first boat(s) called me recently. He's actually
| > building two stitch and glue kayaks. I DID warn him not to build both at
| > once, but I think he was too eager to have an extra boat ready for
friends
| > to paddle with. Now he's in the midst of doubling his mistakes. When he
| > called he expressed concern for how slow the epoxy was curing. He's
using
| > Epiglas, a 4 to 1 epoxy. I asked if he was making sure of the 4/1
| > ratio and
|
|
|
|
|
| Bolger rules!!!
| - no cursing, flaming, trolling, spamming, or flogging dead horses
| - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
| - Pls add your comments at the TOP, SIGN your posts, and snip away
| - Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax:
(978) 282-1349
| - Unsubscribe:bolger-unsubscribe@yahoogroups.com
| - Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
| Yahoo! Groups Links
|
|
|
|
|
|
A little heat might ause it to kick over a little quicker, but not a lot
of heat as epoxy is degraded by high heat. Also not petrol based heat
like kerosine as the fumes can effect epoxy. Clyde
Jack&Lois wrote:
of heat as epoxy is degraded by high heat. Also not petrol based heat
like kerosine as the fumes can effect epoxy. Clyde
Jack&Lois wrote:
> ...or anyone who has insights into sticky epoxy issues. A good friend who
> has started building his first boat(s) called me recently. He's actually
> building two stitch and glue kayaks. I DID warn him not to build both at
> once, but I think he was too eager to have an extra boat ready for friends
> to paddle with. Now he's in the midst of doubling his mistakes. When he
> called he expressed concern for how slow the epoxy was curing. He's using
> Epiglas, a 4 to 1 epoxy. I asked if he was making sure of the 4/1
> ratio and
I don't know if there's any way to get it adequately mixed in at this stage,
and the results will definitely be iffy, but ...
System Three, in their "Epoxy Book" suggests preparing a "hardener short"
mix in order to have a clear, gap-filling, epoxy. The incomplete mix is
allowed to "cure" and cool for hours. The missing hardener is added at time
of use. Theirs is a 2:1 formula and they suggest using 1/3rd of the needed
hardener for the initial mix and adding the other 2/3rds later. The shelf
life of the preliminary mix seems quite good (days or weeks, not hours).
Roger
derbyrm@...
http://home.earthlink.net/~derbyrm
and the results will definitely be iffy, but ...
System Three, in their "Epoxy Book" suggests preparing a "hardener short"
mix in order to have a clear, gap-filling, epoxy. The incomplete mix is
allowed to "cure" and cool for hours. The missing hardener is added at time
of use. Theirs is a 2:1 formula and they suggest using 1/3rd of the needed
hardener for the initial mix and adding the other 2/3rds later. The shelf
life of the preliminary mix seems quite good (days or weeks, not hours).
Roger
derbyrm@...
http://home.earthlink.net/~derbyrm
----- Original Message -----
From: "Jack&Lois" <jalo@...>
> ...or anyone who has insights into sticky epoxy issues. A good friend who
> has started building his first boat(s) called me recently. He's actually
> building two stitch and glue kayaks. I DID warn him not to build both at
> once, but I think he was too eager to have an extra boat ready for friends
> to paddle with. Now he's in the midst of doubling his mistakes. When he
> called he expressed concern for how slow the epoxy was curing. He's using
> Epiglas, a 4 to 1 epoxy. I asked if he was making sure of the 4/1 ratio
> and
> he assured me he was but thought there might be something wrong with the
> pumps. I asked if he was being sure to carefully and slowly completely
> press
> down each pump 1 for 1. After a long pause he said no, he was doing 4
> squirts of resin to 1 squirt of hardener. I nearly dropped the phone. He's
> trying to build TWO kayaks using a 16/1 epoxy mix. Here are my questions:
>
> Will the magical chain reaction that turns liquid resin to a solid
> eventually occur, even with a really feeble mix?
>
> If he applies a layer of a somewhat rich mix, say 3/1, to a sticky layer
> of
> 16/1, will the curing epoxy kick off the sticky stuff?
>
> His initial butt joints actually have cured to the point of no longer
> being
> tacky. Should he take heart in that or are those joints likely to always
> be
> weak? After spending so much time in the moaning chair myself, through
> various projects, I hate to see a friend being hit by so much
> discouragement
> his first time out. I feel especially bad since I'm the one who encouraged
> him to buy the pumps.
>
> jeb, watching endless rain fall on the unforgiving shores of Fundy
>
>
>
>
>
>
>
> Bolger rules!!!
> - no cursing, flaming, trolling, spamming, or flogging dead horses
> - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
> - Pls add your comments at the TOP, SIGN your posts, and snip away
> - Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax:
> (978) 282-1349
> - Unsubscribe:bolger-unsubscribe@yahoogroups.com
> - Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
> Yahoo! Groups Links
>
>
>
>
>
>
>
Epoxy resins require a more or less stoichiometric mix of the two parts in
order to achieve its full properties. Your friend's mix will not be very
strong or waterproof.
He needs a gallon or two of acetone and a scraper, 'cuz it's all gotta come
off.
JB (a chemist, really!)
order to achieve its full properties. Your friend's mix will not be very
strong or waterproof.
He needs a gallon or two of acetone and a scraper, 'cuz it's all gotta come
off.
JB (a chemist, really!)
----- Original Message -----
From: "Jack&Lois" <jalo@...>
To: <bolger@yahoogroups.com>
Sent: Friday, May 27, 2005 11:48 PM
Subject: [bolger] A call for chemists
| ...or anyone who has insights into sticky epoxy issues. A good friend who
| has started building his first boat(s) called me recently. He's actually
| building two stitch and glue kayaks. I DID warn him not to build both at
| once, but I think he was too eager to have an extra boat ready for friends
| to paddle with. Now he's in the midst of doubling his mistakes. When he
| called he expressed concern for how slow the epoxy was curing. He's using
| Epiglas, a 4 to 1 epoxy. I asked if he was making sure of the 4/1 ratio
and
| he assured me he was but thought there might be something wrong with the
| pumps. I asked if he was being sure to carefully and slowly completely
press
| down each pump 1 for 1. After a long pause he said no, he was doing 4
| squirts of resin to 1 squirt of hardener. I nearly dropped the phone. He's
| trying to build TWO kayaks using a 16/1 epoxy mix. Here are my questions:
|
| Will the magical chain reaction that turns liquid resin to a solid
| eventually occur, even with a really feeble mix?
|
| If he applies a layer of a somewhat rich mix, say 3/1, to a sticky layer
of
| 16/1, will the curing epoxy kick off the sticky stuff?
|
| His initial butt joints actually have cured to the point of no longer
being
| tacky. Should he take heart in that or are those joints likely to always
be
| weak? After spending so much time in the moaning chair myself, through
| various projects, I hate to see a friend being hit by so much
discouragement
| his first time out. I feel especially bad since I'm the one who encouraged
| him to buy the pumps.
|
| jeb, watching endless rain fall on the unforgiving shores of Fundy
|
|
|
|
|
|
|
| Bolger rules!!!
| - no cursing, flaming, trolling, spamming, or flogging dead horses
| - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
| - Pls add your comments at the TOP, SIGN your posts, and snip away
| - Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax:
(978) 282-1349
| - Unsubscribe:bolger-unsubscribe@yahoogroups.com
| - Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
| Yahoo! Groups Links
|
|
|
|
|
|
Not a chemist, but plenty of epoxy experience.
In my experience accurate mixing is essential for epoxy - it's not very forgiving when things are that far out. I once had to scrape off a badly mixed batch that hadn't cured after a couple of weeks..
I suppose the upside is that if it's not hardened, it should be easier to scrape off.
Hopefully he hasn't done too much of the job before discovering this?
Bill
In my experience accurate mixing is essential for epoxy - it's not very forgiving when things are that far out. I once had to scrape off a badly mixed batch that hadn't cured after a couple of weeks..
I suppose the upside is that if it's not hardened, it should be easier to scrape off.
Hopefully he hasn't done too much of the job before discovering this?
Bill
----- Original Message -----
From: Jack&Lois
To:bolger@yahoogroups.com
Sent: Saturday, May 28, 2005 4:48 AM
Subject: [bolger] A call for chemists
...or anyone who has insights into sticky epoxy issues. A good friend who
has started building his first boat(s) called me recently. He's actually
building two stitch and glue kayaks. I DID warn him not to build both at
once, but I think he was too eager to have an extra boat ready for friends
to paddle with. Now he's in the midst of doubling his mistakes. When he
called he expressed concern for how slow the epoxy was curing. He's using
Epiglas, a 4 to 1 epoxy. I asked if he was making sure of the 4/1 ratio and
he assured me he was but thought there might be something wrong with the
pumps. I asked if he was being sure to carefully and slowly completely press
down each pump 1 for 1. After a long pause he said no, he was doing 4
squirts of resin to 1 squirt of hardener. I nearly dropped the phone. He's
trying to build TWO kayaks using a 16/1 epoxy mix. Here are my questions:
Will the magical chain reaction that turns liquid resin to a solid
eventually occur, even with a really feeble mix?
If he applies a layer of a somewhat rich mix, say 3/1, to a sticky layer of
16/1, will the curing epoxy kick off the sticky stuff?
His initial butt joints actually have cured to the point of no longer being
tacky. Should he take heart in that or are those joints likely to always be
weak? After spending so much time in the moaning chair myself, through
various projects, I hate to see a friend being hit by so much discouragement
his first time out. I feel especially bad since I'm the one who encouraged
him to buy the pumps.
jeb, watching endless rain fall on the unforgiving shores of Fundy
Bolger rules!!!
- no cursing, flaming, trolling, spamming, or flogging dead horses
- stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
- Pls add your comments at the TOP, SIGN your posts, and snip away
- Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax: (978) 282-1349
- Unsubscribe:bolger-unsubscribe@yahoogroups.com
- Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
------------------------------------------------------------------------------
Yahoo! Groups Links
a.. To visit your group on the web, go to:
http://groups.yahoo.com/group/bolger/
b.. To unsubscribe from this group, send an email to:
bolger-unsubscribe@yahoogroups.com
c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Non-text portions of this message have been removed]
...or anyone who has insights into sticky epoxy issues. A good friend who
has started building his first boat(s) called me recently. He's actually
building two stitch and glue kayaks. I DID warn him not to build both at
once, but I think he was too eager to have an extra boat ready for friends
to paddle with. Now he's in the midst of doubling his mistakes. When he
called he expressed concern for how slow the epoxy was curing. He's using
Epiglas, a 4 to 1 epoxy. I asked if he was making sure of the 4/1 ratio and
he assured me he was but thought there might be something wrong with the
pumps. I asked if he was being sure to carefully and slowly completely press
down each pump 1 for 1. After a long pause he said no, he was doing 4
squirts of resin to 1 squirt of hardener. I nearly dropped the phone. He's
trying to build TWO kayaks using a 16/1 epoxy mix. Here are my questions:
Will the magical chain reaction that turns liquid resin to a solid
eventually occur, even with a really feeble mix?
If he applies a layer of a somewhat rich mix, say 3/1, to a sticky layer of
16/1, will the curing epoxy kick off the sticky stuff?
His initial butt joints actually have cured to the point of no longer being
tacky. Should he take heart in that or are those joints likely to always be
weak? After spending so much time in the moaning chair myself, through
various projects, I hate to see a friend being hit by so much discouragement
his first time out. I feel especially bad since I'm the one who encouraged
him to buy the pumps.
jeb, watching endless rain fall on the unforgiving shores of Fundy
has started building his first boat(s) called me recently. He's actually
building two stitch and glue kayaks. I DID warn him not to build both at
once, but I think he was too eager to have an extra boat ready for friends
to paddle with. Now he's in the midst of doubling his mistakes. When he
called he expressed concern for how slow the epoxy was curing. He's using
Epiglas, a 4 to 1 epoxy. I asked if he was making sure of the 4/1 ratio and
he assured me he was but thought there might be something wrong with the
pumps. I asked if he was being sure to carefully and slowly completely press
down each pump 1 for 1. After a long pause he said no, he was doing 4
squirts of resin to 1 squirt of hardener. I nearly dropped the phone. He's
trying to build TWO kayaks using a 16/1 epoxy mix. Here are my questions:
Will the magical chain reaction that turns liquid resin to a solid
eventually occur, even with a really feeble mix?
If he applies a layer of a somewhat rich mix, say 3/1, to a sticky layer of
16/1, will the curing epoxy kick off the sticky stuff?
His initial butt joints actually have cured to the point of no longer being
tacky. Should he take heart in that or are those joints likely to always be
weak? After spending so much time in the moaning chair myself, through
various projects, I hate to see a friend being hit by so much discouragement
his first time out. I feel especially bad since I'm the one who encouraged
him to buy the pumps.
jeb, watching endless rain fall on the unforgiving shores of Fundy