Glue Creep - Was Bent Lamination
 

Below is an interesting thread on glue creep.
In furniture making or general woodworking I have never experienced glue
creeping after the glue has set. Yet others (below) have or are concerned
about it.
Has anyone ever seen this situation (other than structural adhesives or
severe heat/abuse)?

Dave


--
Dave said:
Creep is what happens to the wood sandwich as clamping
pressures are applied. Blue tape will hold it most of the time for flat
stock glue ups, it has a hard time when the form includes a bend and twist.
Unless your bending form incorporates a twist as well as a bend, you should
not have a problem with creep. If you do, and blue tape will not hold, (try
it without glue first) apply clamps and cauls to prevent severe creep. Use
clear packing tape on the cauls to prevent the adhesive from sticking to it.

Alex said:
Okay. That's not my understanding of the term. I think it refers to a
property of the cured glue line. From an engineering dictionary:
:Creep - the dimensional change with time of a material under load.
and from the Franklin Global web site:
What is creep in an adhesive bond?
Creep or cold-flow in an adhesive bond is the deformation of
the bond line under a stress or load over a period of time

Dave said:
Alex, I don't think that applies to furniture making. Structural materials,
subject to significant pressures and/or vibration and large temperature
fluctuations, maybe. If you are making a glue lamination beam (GLB), that
may have to hold during a fire, then I'd worry about that type of creep.

Andy said:
The most common sense of "glue creep" in woodworking is pretty
much Alex's, but perhaps with 'time' replacing 'load'. Concretely,
it's the phenomenon of having two pieces glued together become non-flush
with one another at the glue line. Most common with white and yellow
glues.



--
Today's mighty oak is just yesterday's nut that held its ground.



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Glue Creep - Was Bent Lamination
 

"Teamcasa" wrote in message
...
Below is an interesting thread on glue creep.
In furniture making or general woodworking I have never experienced glue
creeping after the glue has set. Yet others (below) have or are concerned
about it.
Has anyone ever seen this situation (other than structural adhesives or
severe heat/abuse)?

PVA Glue never sets hard, it remains slightly gooey when dry and allows a
little creeping. This can be good or bad. I have seen it many times.

If you glue up boards edge to edge to make a table top with PVA and you want
a fine finish you will never with any amount of sanding be able to make the
glue line disappear, because the movement of the wood will perpetually cause
creeping in the joint. It is very slight but quite visible with a fine
finish. The best glue for that kind of application is therefore one which
sets hard like a rock like Cascamite. If you want to joint across the grain
then creeping can be a distinct advantage because it allows a little
movement without the joint breaking or the wood splitting.

Tim W

Glue Creep - Was Bent Lamination
 

"Teamcasa" wrote in message
Below is an interesting thread on glue creep.
In furniture making or general woodworking I have never experienced glue
creeping after the glue has set. Yet others (below) have or are concerned
about it.
Has anyone ever seen this situation (other than structural adhesives or
severe heat/abuse)?

I see ("feel" may be a better word, as it often hard to see) it to some
extent on the occasional glue joint after a period of time, most noticeable
on glued up panels during normal rh/temp changes.

Keep in mind that some woods, or cuts, may expand in thickness more than
they do across the grain. QSWO seems to one of these where the phenomenon
can often be seen, particularly when using thicker stock than the normal
3/4.

--
www.e-woodshop.net
Last update: 10/01/06

Glue Creep - Was Bent Lamination
 

Teamcasa wrote:
Below is an interesting thread on glue creep.
In furniture making or general woodworking I have never experienced glue
creeping after the glue has set. Yet others (below) have or are concerned
about it.
Has anyone ever seen this situation (other than structural adhesives or
severe heat/abuse)?

Dave


--
Dave said:
Creep is what happens to the wood sandwich as clamping
pressures are applied. Blue tape will hold it most of the time for flat
stock glue ups, it has a hard time when the form includes a bend and twist.
Unless your bending form incorporates a twist as well as a bend, you should
not have a problem with creep. If you do, and blue tape will not hold, (try
it without glue first) apply clamps and cauls to prevent severe creep. Use
clear packing tape on the cauls to prevent the adhesive from sticking to it.

Alex said:
Okay. That's not my understanding of the term. I think it refers to a
property of the cured glue line. From an engineering dictionary:
:Creep - the dimensional change with time of a material under load.
and from the Franklin Global web site:
What is creep in an adhesive bond?
Creep or cold-flow in an adhesive bond is the deformation of
the bond line under a stress or load over a period of time

Dave said:
Alex, I don't think that applies to furniture making. Structural materials,
subject to significant pressures and/or vibration and large temperature
fluctuations, maybe. If you are making a glue lamination beam (GLB), that
may have to hold during a fire, then I'd worry about that type of creep.

Andy said:
The most common sense of "glue creep" in woodworking is pretty
much Alex's, but perhaps with 'time' replacing 'load'. Concretely,
it's the phenomenon of having two pieces glued together become non-flush
with one another at the glue line. Most common with white and yellow
glues.



White glue exhibits creep with higher
temperatures. Never seen creep with a yellow glue
(carpenters) and I have made pieces that creep
would be obvious. Also, I have never seen a
mention of creep, except with white glue, in a
table of glues and their properties.

Glue Creep - Was Bent Lamination
 

Here's a column discxussing various senses of "glue creep", and various
glues:

http://www.woodworkersjournal.com/ez...43/readers.cfm

Glue Creep - Was Bent Lamination
 

Swingman wrote:
this situation (other than structural adhesives or
severe heat/abuse)?

I see ("feel" may be a better word, as it often hard to see) it to some
extent on the occasional glue joint after a period of time, most noticeable
on glued up panels during normal rh/temp changes.

I wonder if the thickness of the glue joint matters?

For instance, if the joint is an ultra-thin, smooth, edge-to-edge vs. a
rougher surface to rougher surface interface. While both would look
great, the rough surfaces would use more glue and potentially allow more
crrep?

Glue Creep - Was Bent Lamination - Updated
 

From Franklin

Thank you for your inquiry. A bent lamination is the type of application
where our wood glues would most likely creep. Creep generally occurs where
the glue line is under a permanent stress. Some of our wood glues provide a
harder glue line when dry and would be less likely to creep. The wood glues
that provide good creep resistance are Titebond Liquid Hide Glue, Titebond
Extend Wood Glue and Titebond Polyurethane Glue. Titebond III is not a
product that is considered to have good creep resistance. The amount of
success using Titebond III for a bent lamination will depend on the
thickness of the material and the degree of the bend. It is a good idea to
allow the wood glue to reach full strength before releasing from the clamps
when doing a bent lamination. I normally recommend clamping bent
laminations for at least 24 hours. The actual clamp time will depend on the
type of wood, moisture content of the wood, numbers of layers of wood and
conditions in the shop. All these factors will affect the drying time for
the glue. I hope this information is helpful to you.

Sincerely,

Marc Bergdahl
Technical Specialist
Franklin International



"Teamcasa" wrote in message
...
Below is an interesting thread on glue creep.
In furniture making or general woodworking I have never experienced glue
creeping after the glue has set. Yet others (below) have or are concerned
about it.
Has anyone ever seen this situation (other than structural adhesives or
severe heat/abuse)?

Dave


--
Dave said:
Creep is what happens to the wood sandwich as clamping
pressures are applied. Blue tape will hold it most of the time for flat
stock glue ups, it has a hard time when the form includes a bend and
twist.
Unless your bending form incorporates a twist as well as a bend, you
should
not have a problem with creep. If you do, and blue tape will not hold,
(try
it without glue first) apply clamps and cauls to prevent severe creep. Use
clear packing tape on the cauls to prevent the adhesive from sticking to
it.

Alex said:
Okay. That's not my understanding of the term. I think it refers to a
property of the cured glue line. From an engineering dictionary:
:Creep - the dimensional change with time of a material under load.
and from the Franklin Global web site:
What is creep in an adhesive bond?
Creep or cold-flow in an adhesive bond is the deformation of
the bond line under a stress or load over a period of time

Dave said:
Alex, I don't think that applies to furniture making. Structural
materials,
subject to significant pressures and/or vibration and large temperature
fluctuations, maybe. If you are making a glue lamination beam (GLB), that
may have to hold during a fire, then I'd worry about that type of creep.

Andy said:
The most common sense of "glue creep" in woodworking is pretty
much Alex's, but perhaps with 'time' replacing 'load'. Concretely,
it's the phenomenon of having two pieces glued together become non-flush
with one another at the glue line. Most common with white and yellow
glues.



--
Today's mighty oak is just yesterday's nut that held its ground.



Posted Via Usenet.com Premium Usenet Newsgroup Services
----------------------------------------------------------
** SPEED ** RETENTION ** COMPLETION ** ANONYMITY **
----------------------------------------------------------
http://www.usenet.com



Posted Via Usenet.com Premium Usenet Newsgroup Services
----------------------------------------------------------
** SPEED ** RETENTION ** COMPLETION ** ANONYMITY **
----------------------------------------------------------
http://www.usenet.com

Glue Creep - Was Bent Lamination
 

"Teamcasa" wrote:

Below is an interesting thread on glue creep.
In furniture making or general woodworking I have never experienced glue
creeping after the glue has set. Yet others (below) have or are concerned
about it.
Has anyone ever seen this situation (other than structural adhesives or
severe heat/abuse)?

Dave
Interesting. Thanks for creating a new thread for this, Dave. The
context in which I have seen the discussion most is in the
recommendation of plastic resin (urea formaldehyde) glue for bent
laminations, in which sheer forces ARE significant, and there is no
mechanical joint to keep the joint from moving if the glue allows
creep.

When I get a chance, I will run a test with laminations glued with
different glues, to see what kind of results I get. Will report back
here.
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.

Glue Creep - Was Bent Lamination - Updated
 

Teamcasa wrote:
From Franklin

Thank you for your inquiry.

EXCELLENT info!

Thanks for taking the time to put the question to Franklin and sharing
it with the rest of us.

Glue Creep - Was Bent Lamination
 

Alexy,

Most tillers are made from 10 plus one-eighth inch thick pieces of Mahogany
and Ash laminated together. The adhesive used is epoxy {with the proper
'fillers' to have it act as a glue}. The final touches are cut or carved,
and the finish is {SHOULD be} 6 & up coats of 'short-oil' UV varnish.

The handling, being banged about, and 24/7 exposure to weather {in more
cases then not}is probably the harshest treatment for such a structure

I have heard of tillers have been abused or even broken, but never by
delaminating, or the surface appearance of 'glue creep'.

Regards & Good Luck,
Ron Magen
Backyard Boatshop

"alexy" wrote in message
...
"Teamcasa" wrote:

Below is an interesting thread on glue creep.
In furniture making or general woodworking I have never experienced glue
creeping after the glue has set. Yet others (below) have or are
concerned
about it.
Has anyone ever seen this situation (other than structural adhesives or
severe heat/abuse)?

Dave
Interesting. Thanks for creating a new thread for this, Dave. The
context in which I have seen the discussion most is in the
recommendation of plastic resin (urea formaldehyde) glue for bent
laminations, in which sheer forces ARE significant, and there is no
mechanical joint to keep the joint from moving if the glue allows
creep.

When I get a chance, I will run a test with laminations glued with
different glues, to see what kind of results I get. Will report back
here.
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked
infrequently.