Re: [bolger] Re: Gorilla Glue - limitations
My apologies, Bruce. I definitely misinterpreted the picture. I thought that the failure was along the scarf, rather than through the ply.
Chuck
The picture may not be clear, but I inspected it real close and the
plane of failure was right at the edge of the glued joint, and the
point of weakness seems to be a failure of the very thin outer
laminate in the cheapo luaun plywood I was using. The plane of
failure was perpendicular to the surface of the plywood, not at a 1:8
angle which you would expect if the glue was to fail. - Bruce
[Non-text portions of this message have been removed]
Chuck
The picture may not be clear, but I inspected it real close and the
plane of failure was right at the edge of the glued joint, and the
point of weakness seems to be a failure of the very thin outer
laminate in the cheapo luaun plywood I was using. The plane of
failure was perpendicular to the surface of the plywood, not at a 1:8
angle which you would expect if the glue was to fail. - Bruce
[Non-text portions of this message have been removed]
--- In bolger@y..., "Chuck Leinweber" <chuck_dm@y...> wrote:
linear "smear" of excess glue that overflowed from the joint, with
the smear made flat by my use of a strip of packaging tape run along
the joint over the wet glue. This was to prevent the plywood from
adhering to the clamping board and/or my work bench.
The picture may not be clear, but I inspected it real close and the
plane of failure was right at the edge of the glued joint, and the
point of weakness seems to be a failure of the very thin outer
laminate in the cheapo luaun plywood I was using. The plane of
failure was perpendicular to the surface of the plywood, not at a 1:8
angle which you would expect if the glue was to fail.
It appears somehow that the section at the glued scarf joint is
stiffer in deflection than 'plain' plywood, causing a concentration
of stress right next to the joint. Perhaps the glue in the scarf
joint penetrates into the nearby wood fibers 'locking' fibers
together making things stiff in that immediate area, where nearby
wood is full of air and weaker.
> Am I missing something? This looks like joint failure to me.In the picture the scarf joint is not as obvious as the
linear "smear" of excess glue that overflowed from the joint, with
the smear made flat by my use of a strip of packaging tape run along
the joint over the wet glue. This was to prevent the plywood from
adhering to the clamping board and/or my work bench.
The picture may not be clear, but I inspected it real close and the
plane of failure was right at the edge of the glued joint, and the
point of weakness seems to be a failure of the very thin outer
laminate in the cheapo luaun plywood I was using. The plane of
failure was perpendicular to the surface of the plywood, not at a 1:8
angle which you would expect if the glue was to fail.
It appears somehow that the section at the glued scarf joint is
stiffer in deflection than 'plain' plywood, causing a concentration
of stress right next to the joint. Perhaps the glue in the scarf
joint penetrates into the nearby wood fibers 'locking' fibers
together making things stiff in that immediate area, where nearby
wood is full of air and weaker.
> I just 'experimented' by breaking an 8:1 scarf joint in 1/8" luaunAgreed, but destructive failure is only one kind. And it is other
> plywood. The failure was in the wood immediately next to the glue
> joint. The glue did not fail.
>
> See photo at:
>http://www.hallman.org/bolger/scarf.jpg
>
> I agree that epoxy is better. But what good is better, if it is
> beyond 'good enough'?
kinds of failure like those related to creep where epoxy shines.
Boat hulls are not all that heavily stressed just from normal
floating around. And I don't think most of us are planing super
heavy use, but if you are really putting these materials to long term
test, you need machines that do many cycles to failure.
I am perplexed by the photo. You must be murder on phone books. I
don't think I could just rip a piece of 1/8" plywood accross the
grain like that. Must save enourmously on sawblades. It seems to
ripped right down the middle of the joint. Even if you pulled a few
fibers away from either side, I can't see why it should have torn
apart where it did
I just 'experimented' by breaking an 8:1 scarf joint in 1/8" luaun
plywood. The failure was in the wood immediately next to the glue
joint. The glue did not fail.
See photo at:
http://www.hallman.org/bolger/scarf.jpg
Am I missing something? This looks like joint failure to me. The separation was at the glue/wood interface (unless I am looking at the wrong picture) not in the wood. If it were a good joint, the break would not follow the joint, but would travel across the ply in some other direction. That said, it might still be good enough for some applications.
Chuck
[Non-text portions of this message have been removed]
plywood. The failure was in the wood immediately next to the glue
joint. The glue did not fail.
See photo at:
http://www.hallman.org/bolger/scarf.jpg
Am I missing something? This looks like joint failure to me. The separation was at the glue/wood interface (unless I am looking at the wrong picture) not in the wood. If it were a good joint, the break would not follow the joint, but would travel across the ply in some other direction. That said, it might still be good enough for some applications.
Chuck
[Non-text portions of this message have been removed]
> With the big warning 'lots of water needed in the joint'; based on myMy experience exactly. I've used about a gallon of the stuff already on the
> experiment, I conclude that Gorilla Glue is stronger than wood and
> that Gorilla glue is good enough for most normal situations. It also
> is easier to use.
Wyoming. I have a spray bottle of water and mist both pieces to be glued.
What I see happening is that the wood then does not wick the glue into the
grain as much leaving more in the joint and of course the PL glues are
activated by moisture. Very much the same as priming an epoxy joint before
gluing with thickened epoxy to keep form getting a dry joint.
As for high stress and shock loads on some joints like the stem, chines, and
rub rails, I use epoxy. No sense in pushing the limits of a glue for
convenience.
Again, my experience is strictly with Meranti plywood and cedar.
Jeff
Hi Bruce,
Actually, I had not seen the web site when I made the picture frames.
The frames were actually softwood (clear grade pinus radiata), and I
really well wet them with a fully saturated sponge - in fact I
thought after the failure that I must have over-wetted it. Don't see
how I didn't comply with the instructions in any way. The joinig
faces were perfect and tightly held. I suspect the glue is not very
satisfactory for end grain, unless in larger area like your scarphs.
The thing is, epoxy is very forgiving, you would have to grossly
ignore the instructions to have a total joint failure of this type.
Your boat has yet to be tested, and I wish you success, but once the
trust is gone, as in my case and several others, I will be very wary
of Gorilla except under limited conditions. I did want it to work for
it's other advantages you mention.
DonB
Actually, I had not seen the web site when I made the picture frames.
The frames were actually softwood (clear grade pinus radiata), and I
really well wet them with a fully saturated sponge - in fact I
thought after the failure that I must have over-wetted it. Don't see
how I didn't comply with the instructions in any way. The joinig
faces were perfect and tightly held. I suspect the glue is not very
satisfactory for end grain, unless in larger area like your scarphs.
The thing is, epoxy is very forgiving, you would have to grossly
ignore the instructions to have a total joint failure of this type.
Your boat has yet to be tested, and I wish you success, but once the
trust is gone, as in my case and several others, I will be very wary
of Gorilla except under limited conditions. I did want it to work for
it's other advantages you mention.
DonB
--- In bolger@y..., "brucehallman" <brucehallman@y...> wrote:
> --- In bolger@y..., "dbaldnz" <oink@p...> wrote:
> > 3 of the 4 frames fell
> > apart while I hand sanded them!
>
> The GG website says that 95% of the
> joint failures are caused by lack of
> moisture. They recommend 10% to 25%
> moisture content. 25% moisture in wood
> is "squirt you in the eye" wet.
>
> Perhaps the density of the hardwood
> in the picture frames prevented the
> moisture from soaking into the wood?
>
> > My experiences have been endorsed by
> > several experimenters in other Groups.
>
> I just 'experimented' by breaking an 8:1 scarf joint in 1/8" luaun
> plywood. The failure was in the wood immediately next to the glue
> joint. The glue did not fail.
>
> See photo at:
>http://www.hallman.org/bolger/scarf.jpg
>
> I agree that epoxy is better. But what good is better, if it is
> beyond 'good enough'?
>
> With the big warning 'lots of water needed in the joint'; based on
my
> experiment, I conclude that Gorilla Glue is stronger than wood and
> that Gorilla glue is good enough for most normal situations. It
also
> is easier to use.
--- In bolger@y..., "dbaldnz" <oink@p...> wrote:
joint failures are caused by lack of
moisture. They recommend 10% to 25%
moisture content. 25% moisture in wood
is "squirt you in the eye" wet.
Perhaps the density of the hardwood
in the picture frames prevented the
moisture from soaking into the wood?
plywood. The failure was in the wood immediately next to the glue
joint. The glue did not fail.
See photo at:
http://www.hallman.org/bolger/scarf.jpg
I agree that epoxy is better. But what good is better, if it is
beyond 'good enough'?
With the big warning 'lots of water needed in the joint'; based on my
experiment, I conclude that Gorilla Glue is stronger than wood and
that Gorilla glue is good enough for most normal situations. It also
is easier to use.
> 3 of the 4 frames fellThe GG website says that 95% of the
> apart while I hand sanded them!
joint failures are caused by lack of
moisture. They recommend 10% to 25%
moisture content. 25% moisture in wood
is "squirt you in the eye" wet.
Perhaps the density of the hardwood
in the picture frames prevented the
moisture from soaking into the wood?
> My experiences have been endorsed byI just 'experimented' by breaking an 8:1 scarf joint in 1/8" luaun
> several experimenters in other Groups.
plywood. The failure was in the wood immediately next to the glue
joint. The glue did not fail.
See photo at:
http://www.hallman.org/bolger/scarf.jpg
I agree that epoxy is better. But what good is better, if it is
beyond 'good enough'?
With the big warning 'lots of water needed in the joint'; based on my
experiment, I conclude that Gorilla Glue is stronger than wood and
that Gorilla glue is good enough for most normal situations. It also
is easier to use.
Plans call for glue and nails. It'll basically rip the ply layer apart or
the cedar will split out. I've test the joint many ways ( no fasteners),
even slamming it down across the saw horses. Used right it works. It
could never replace epoxy for the ultimate glue for boats. I limit it to
inside joints not eposed to weather or water. AND to large flat gluing
surfaces.
It simply is faster to use than epoxy. Not better, but good enough to hold
past the capabilities of the wood. At least on Meranti and Cedar.
Jeff
the cedar will split out. I've test the joint many ways ( no fasteners),
even slamming it down across the saw horses. Used right it works. It
could never replace epoxy for the ultimate glue for boats. I limit it to
inside joints not eposed to weather or water. AND to large flat gluing
surfaces.
It simply is faster to use than epoxy. Not better, but good enough to hold
past the capabilities of the wood. At least on Meranti and Cedar.
Jeff
----- Original Message -----
From: "Nickerson, Bruce " <nickerb@...>
To: <bolger@yahoogroups.com>
Sent: Tuesday, June 04, 2002 8:50 AM
Subject: RE: [bolger] Gorilla Glue - limitations
> Seems you are using Gorilla Glue essentially as a wood gasket!
>
> -----Original Message-----
> From: jeff [mailto:boatbuilding@...]
> Sent: Tuesday, June 04, 2002 10:49 AM
> To:bolger@yahoogroups.com
> Subject: Re: [bolger] Gorilla Glue - limitations
>
>
> > I will still keep a bottle of Gorilla glue in my workshop, for use on
> > flat machined faces, no cut joints, for interior use, non-structural,
> > where mechanical fasteners are permanent. For those applications it
> > will be perfect.
>
> Exactly how I've uses it on my Wyoming. Large flat sanded surfaces that
can
> be clamped or screwed down tight. Don't expect this stuff to fill gaps
and
> have any strength at all! It's just foam that you can dig out with screw
> driver easily. But, where it's clamped tight, it'll hold better than the
> wood. Every where I've used the stuff, I have kept the screws or boat
nails
> in place.
>
> Jeff
>
>
> Bolger rules!!!
> - no cursing, flaming, trolling, spamming, or flogging dead horses
> - stay on topic, stay on thread, punctuate, no "Ed, thanks, Fred" posts
> - add your comments at the TOP and SIGN your posts and <snip> away
> - To order plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA,
> 01930, Fax: (978) 282-1349
> - Unsubscribe:bolger-unsubscribe@yahoogroups.com
>
> Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service
> <http://docs.yahoo.com/info/terms/> .
>
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
> Bolger rules!!!
> - no cursing, flaming, trolling, spamming, or flogging dead horses
> - stay on topic, stay on thread, punctuate, no "Ed, thanks, Fred" posts
> - add your comments at the TOP and SIGN your posts and <snip> away
> - To order plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA,
01930, Fax: (978) 282-1349
> - Unsubscribe:bolger-unsubscribe@yahoogroups.com
>
> Your use of Yahoo! Groups is subject tohttp://docs.yahoo.com/info/terms/
>
>
Seems you are using Gorilla Glue essentially as a wood gasket!
-----Original Message-----
From: jeff [mailto:boatbuilding@...]
Sent: Tuesday, June 04, 2002 10:49 AM
To:bolger@yahoogroups.com
Subject: Re: [bolger] Gorilla Glue - limitations
be clamped or screwed down tight. Don't expect this stuff to fill gaps and
have any strength at all! It's just foam that you can dig out with screw
driver easily. But, where it's clamped tight, it'll hold better than the
wood. Every where I've used the stuff, I have kept the screws or boat nails
in place.
Jeff
Bolger rules!!!
- no cursing, flaming, trolling, spamming, or flogging dead horses
- stay on topic, stay on thread, punctuate, no "Ed, thanks, Fred" posts
- add your comments at the TOP and SIGN your posts and <snip> away
- To order plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA,
01930, Fax: (978) 282-1349
- Unsubscribe:bolger-unsubscribe@yahoogroups.com
Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service
<http://docs.yahoo.com/info/terms/> .
[Non-text portions of this message have been removed]
-----Original Message-----
From: jeff [mailto:boatbuilding@...]
Sent: Tuesday, June 04, 2002 10:49 AM
To:bolger@yahoogroups.com
Subject: Re: [bolger] Gorilla Glue - limitations
> I will still keep a bottle of Gorilla glue in my workshop, for use onExactly how I've uses it on my Wyoming. Large flat sanded surfaces that can
> flat machined faces, no cut joints, for interior use, non-structural,
> where mechanical fasteners are permanent. For those applications it
> will be perfect.
be clamped or screwed down tight. Don't expect this stuff to fill gaps and
have any strength at all! It's just foam that you can dig out with screw
driver easily. But, where it's clamped tight, it'll hold better than the
wood. Every where I've used the stuff, I have kept the screws or boat nails
in place.
Jeff
Bolger rules!!!
- no cursing, flaming, trolling, spamming, or flogging dead horses
- stay on topic, stay on thread, punctuate, no "Ed, thanks, Fred" posts
- add your comments at the TOP and SIGN your posts and <snip> away
- To order plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA,
01930, Fax: (978) 282-1349
- Unsubscribe:bolger-unsubscribe@yahoogroups.com
Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service
<http://docs.yahoo.com/info/terms/> .
[Non-text portions of this message have been removed]
> I will still keep a bottle of Gorilla glue in my workshop, for use onExactly how I've uses it on my Wyoming. Large flat sanded surfaces that can
> flat machined faces, no cut joints, for interior use, non-structural,
> where mechanical fasteners are permanent. For those applications it
> will be perfect.
be clamped or screwed down tight. Don't expect this stuff to fill gaps and
have any strength at all! It's just foam that you can dig out with screw
driver easily. But, where it's clamped tight, it'll hold better than the
wood. Every where I've used the stuff, I have kept the screws or boat nails
in place.
Jeff
There has been a fair bit of euphoria expressed here about Gorilla
glue, about how I felt when I first squirted a Gorilla bottle.
Epoxy is wonderful stuff, I have been using it on boats for 25years,
and never a failure. But it is expensive, messy, temperature
sensitive, etc etc, you all know it all.
Gorilla is easy, one swipe with a damp cloth, a squirt on one side of
the joint from a convenient gottle, clamp and you are done.
The Gorilla bottle is covered with garish labels and slogans, at
least in NZ. Examining them closely is interesting-
"The ultimate toughest adhesive", then under the
disclaimers "WARNING, this is not a structural adhesive" (never saw
an epoxy label claiming epoxy is not structural glue).
"Incredibly gapfilling", yes, true, but the glue filling the gaps has
all the strength and consistency of hokey-pokey. So your joints must
be perfect and well clamped....reduces the speed and convenience
advantage compared with epoxy.
Actually the weakness in bulk is a saviour when you study the next
label- "No drip". Well, you find out the first time you use Gorilla,
that it drips like spring showers. Luckily it is so weak when cured,
that a quick flick with a sander turns it to fairy dust. That's the
same material filling your less than 100% perfect joints.
I did do some perfect joints, 4 picture frames with corners mitred on
a bench mitre saw with fine blade. Set them in a jig to hold firmly
to cure, with an additional panel pin through each joint. Later after
curing, 3 of the 4 frames fell apart while I hand sanded them! So
perhaps beware Gorilla on end grain? Glued with epoxy, I could have
framed the Titanic.
Chuck Leinweber said the Gorilla glued bow on his Jonboat fell off
when he clipped a pier on launch day.
"100% waterproof", well, no glue is 100% waterproof, even epoxy. So
the jury is out, but I am wary.
A minor thing, Gorilla cured on humans sets black, and takes 3 days
to wear off. They say to wipe it off with a cloth, but this is not
always possible during a tense construction job on a warm day. The
instructions list no cleaning agents.
Cost, hard to compare.
My experiences have been endorsed by several experimenters in other
Groups.
I will still keep a bottle of Gorilla glue in my workshop, for use on
flat machined faces, no cut joints, for interior use, non-structural,
where mechanical fasteners are permanent. For those applications it
will be perfect.
DonB
glue, about how I felt when I first squirted a Gorilla bottle.
Epoxy is wonderful stuff, I have been using it on boats for 25years,
and never a failure. But it is expensive, messy, temperature
sensitive, etc etc, you all know it all.
Gorilla is easy, one swipe with a damp cloth, a squirt on one side of
the joint from a convenient gottle, clamp and you are done.
The Gorilla bottle is covered with garish labels and slogans, at
least in NZ. Examining them closely is interesting-
"The ultimate toughest adhesive", then under the
disclaimers "WARNING, this is not a structural adhesive" (never saw
an epoxy label claiming epoxy is not structural glue).
"Incredibly gapfilling", yes, true, but the glue filling the gaps has
all the strength and consistency of hokey-pokey. So your joints must
be perfect and well clamped....reduces the speed and convenience
advantage compared with epoxy.
Actually the weakness in bulk is a saviour when you study the next
label- "No drip". Well, you find out the first time you use Gorilla,
that it drips like spring showers. Luckily it is so weak when cured,
that a quick flick with a sander turns it to fairy dust. That's the
same material filling your less than 100% perfect joints.
I did do some perfect joints, 4 picture frames with corners mitred on
a bench mitre saw with fine blade. Set them in a jig to hold firmly
to cure, with an additional panel pin through each joint. Later after
curing, 3 of the 4 frames fell apart while I hand sanded them! So
perhaps beware Gorilla on end grain? Glued with epoxy, I could have
framed the Titanic.
Chuck Leinweber said the Gorilla glued bow on his Jonboat fell off
when he clipped a pier on launch day.
"100% waterproof", well, no glue is 100% waterproof, even epoxy. So
the jury is out, but I am wary.
A minor thing, Gorilla cured on humans sets black, and takes 3 days
to wear off. They say to wipe it off with a cloth, but this is not
always possible during a tense construction job on a warm day. The
instructions list no cleaning agents.
Cost, hard to compare.
My experiences have been endorsed by several experimenters in other
Groups.
I will still keep a bottle of Gorilla glue in my workshop, for use on
flat machined faces, no cut joints, for interior use, non-structural,
where mechanical fasteners are permanent. For those applications it
will be perfect.
DonB