I am getting ready to do a bent lamination, and have questions about
adhesives and springback.
I have heard that urea formaldehyde or plastic resin glue is the best
to use for this application because of the long open time and lack of
creep once set. I am having a hard time finding it, though. I can get
a gallon from Highland Woodworking but because of its relatively short
shelf life, I would end up throwing away 95% of it. Anyone know a good
source for small quantities (Atlanta area desired, but online source
okay, too) or whether another type of glue would work as well. My
application is not load-bearing, and in fact will be "captured" by
another structure. I'm laminating 4 pieces of 1/8" thick poplar for
edge banding of the inside of an elliptical arch cut in plywood.
I have a form for bending my lamination, that I made slightly
undersize, anticipating that there will be some "springback" when the
lamination is removed from the form. Anyone have any ideas or formulas
for estimating how much that will be in advance, or is it just a case
of trial and error?
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.
"alexy" <[email protected]> wrote in message
news:[email protected]...
>I am getting ready to do a bent lamination, and have questions about
> adhesives and springback.
>
> I have heard that urea formaldehyde or plastic resin glue is the best
> to use for this application because of the long open time and lack of
> creep once set. I am having a hard time finding it, though. I can get
> a gallon from Highland Woodworking but because of its relatively short
> shelf life, I would end up throwing away 95% of it. Anyone know a good
> source for small quantities (Atlanta area desired, but online source
> okay, too) or whether another type of glue would work as well. My
> application is not load-bearing, and in fact will be "captured" by
> another structure. I'm laminating 4 pieces of 1/8" thick poplar for
> edge banding of the inside of an elliptical arch cut in plywood.
>
> I have a form for bending my lamination, that I made slightly
> undersize, anticipating that there will be some "springback" when the
> lamination is removed from the form. Anyone have any ideas or formulas
> for estimating how much that will be in advance, or is it just a case
> of trial and error?
> --
> Alex --
Alex, For the project you describe above, I would use polyurethane glue.
Its has sufficient open time for your project. I only use plastic resin
glue when I need + 20 minutes to get the project clamped up.
Dave
snip
>>Alex, For the project you describe above, I would use polyurethane glue.
>>Its has sufficient open time for your project. I only use plastic resin
>>glue when I need + 20 minutes to get the project clamped up.
>>
>>Dave
>>
> I've thought about that, but how is it for creep? My impression is
> that UF and epoxy are better in this regard. But maybe that's academic
> in my relatively low-stress project?
> --
> Alex
I use blue tape to stop creep. Its really not much of an issue unless the
bend is severe. Just make sure you wear nitrile (blue) gloves.
Dave
"alexy" <[email protected]> wrote in message
news:[email protected]...
> Lew Hodgett <[email protected]> wrote:
>
>>alexy wrote:
>>
>> > I've thought about that, but how is it for creep? My impression is
>> > that UF and epoxy are better in this regard. But maybe that's academic
>> > in my relatively low-stress project?
>>
>>SFWIW, For the price of Gorilla Glue or equal, you can add maybe 10%
>>and get epoxy.
>>
>>There is no comparison between epoxy and Gorilla Glue.
>
> Thanks, Lew. I wonder what the trade-offs are between UF and epoxy?
> Sounds like you are a "fan" of epoxy, but there are always tradeoffs.
Lew LOVES epoxy (and must have stock WestSystems). He suggests it for
virtually every fix where an adhesive is used. Since he works on boats, its
a natural choice. For the rest of us, we get to use several diffrent glues.
Dave
"alexy" <[email protected]> wrote in message
news:[email protected]...
> "Teamcasa" <[email protected]> wrote:
>
>>I use blue tape to stop creep.
>
> Either I am misusing the term "creep", or I don't understand what you
> are doing with the blue tape to stop it. I thought that creep in a
> glue joint referred to movement in response to sheer forces.
>
You are not. 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.
Dave
"Lew Hodgett" <[email protected]> wrote in message
news:[email protected]...
> Teamcasa wrote:
>
>
> > Lew LOVES epoxy (and must have stock WestSystems).
>
> Actually, I don't use any West Systems.
>
> They are not competitive for my applications.
>
> The reason I suggest them is that they offer small quantities, are readily
> available almost every place, and they offer very good tech service.
>
>
> Lew
What do you use?
Dave
"alexy" <[email protected]> wrote in message
news:[email protected]...
>I am getting ready to do a bent lamination, and have questions about
> adhesives and springback.
>
> I have heard that urea formaldehyde or plastic resin glue is the best
> to use for this application because of the long open time and lack of
> creep once set. I am having a hard time finding it, though. I can get
> a gallon from Highland Woodworking but because of its relatively short
> shelf life, I would end up throwing away 95% of it. Anyone know a good
> source for small quantities (Atlanta area desired, but online source
> okay, too) or whether another type of glue would work as well. My
> application is not load-bearing, and in fact will be "captured" by
> another structure. I'm laminating 4 pieces of 1/8" thick poplar for
> edge banding of the inside of an elliptical arch cut in plywood.
>
> I have a form for bending my lamination, that I made slightly
> undersize, anticipating that there will be some "springback" when the
> lamination is removed from the form. Anyone have any ideas or formulas
> for estimating how much that will be in advance, or is it just a case
> of trial and error?
> --
> Alex -- Replace "nospam" with "mail" to reply by email. Checked
> infrequently.
Dap makes a powdered version of urea formaldehyde or plastic resin glue .
You mix up the quantity needed for the task at hand. here is one example...
http://www.hardwareworld.com/Lb-Plastic-Resin-Glue-p38H29K.aspx
I found some at my local Ace store.
MikeG
"Teamcasa" <[email protected]> wrote:
>
>"alexy" <[email protected]> wrote in message
>news:[email protected]...
>> "Teamcasa" <[email protected]> wrote:
>>
>>>I use blue tape to stop creep.
>>
>> Either I am misusing the term "creep", or I don't understand what you
>> are doing with the blue tape to stop it. I thought that creep in a
>> glue joint referred to movement in response to sheer forces.
>>
>
>You are not. 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.
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
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.
"Teamcasa" <[email protected]> wrote:
>I use blue tape to stop creep.
Either I am misusing the term "creep", or I don't understand what you
are doing with the blue tape to stop it. I thought that creep in a
glue joint referred to movement in response to sheer forces.
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.
alexy wrote:
> I am getting ready to do a bent lamination, and have questions about
> adhesives and springback.
>
> I have heard that urea formaldehyde or plastic resin glue is the best
> to use for this application because of the long open time and lack of
> creep once set.
<snip>
I use epoxy with a slow hardener.
West System, while expensive, is readily available in small quantities.
Check for an outlet in your area using the West site.
Take a look at Fred Bingham's book for spring back info.
Have fun.
Lew
alexy wrote:
> I've thought about that, but how is it for creep? My impression is
> that UF and epoxy are better in this regard. But maybe that's academic
> in my relatively low-stress project?
SFWIW, For the price of Gorilla Glue or equal, you can add maybe 10%
and get epoxy.
There is no comparison between epoxy and Gorilla Glue.
Lew
J. Clarke wrote:
> "alexy" <[email protected]> wrote in message
> news:[email protected]...
>> I am getting ready to do a bent lamination, and have questions about
>> adhesives and springback.
>>
>> I have heard that urea formaldehyde or plastic resin glue is the best
>> to use for this application because of the long open time and lack of
>> creep once set. I am having a hard time finding it, though. I can get
>> a gallon from Highland Woodworking but because of its relatively short
>> shelf life, I would end up throwing away 95% of it. Anyone know a good
>> source for small quantities (Atlanta area desired, but online source
>> okay, too) or whether another type of glue would work as well. My
>> application is not load-bearing, and in fact will be "captured" by
>> another structure. I'm laminating 4 pieces of 1/8" thick poplar for
>> edge banding of the inside of an elliptical arch cut in plywood.
>
> I think the stuff you're looking for is Weldwood Plastic Resin Glue,
> <http://www.dap.com/product_details.aspx?product_id=42> which is a
> urea-formaldehyde water-activated dry powder FAA approved for aircraft
> construction (in other words this is seriously good stuff). You can get it
> online in one pound containers for about 8 bucks a pound and shipping. Two
> reliable sources are Aircraft Spruce and Specialty
> <http://www.aircraftspruce.com/catalog/wppages/weldwood.php> and Jamestown
> Distributors
> <http://www.jamestowndistributors.com/userportal/show_product.do?pid=2432&familyName=Weldwood+Plastic+Resin+Glue&BASE>.
>
> It used to come in pint cans but now the smallest seems to be a pound. I
> don't know what the real shelf life is--officially it's "1 year minimum" and
> I wouldn't use it older than that for an aircraft, but for noncritical uses
> I have a can that I've been using up gradually that is at least 15 years old
> and still seems to set up fine.
>
I concur on the shelf life, my can of Weldwood
Plastic Resin Glue is over 30 years old. The lid
is tight, has never frozen but the high temp has
been around 90 degrees in the summer (stored in
the garage). I think the last time I used it was
about 5 years ago and it worked fine. You need
close fitting joints as it doesn't fill.
Lots of glues indicate a short shelf life, but
with reasonable storage and use, the shelf life
can be pretty long. My can of Weldwood Waterproof
glue (a liquid resorcinol resin plus a powdered
catalyst) is also 30 years old, actually I bought
it sometime in 1972, and my last use was 2 years
ago on a ceramic figure that had an ear knocked
off. The ear is still on after 2 years outside
being sprinkled in the summer and the sitting in
the hot sun and freezing and being snowed on in
the winter. Good stuff.
((Snipped))
"J. Clarke" <[email protected]> wrote:
>I think the stuff you're looking for is Weldwood Plastic Resin Glue,
<snip>
>It used to come in pint cans but now the smallest seems to be a pound. I
>don't know what the real shelf life is--officially it's "1 year minimum" and
>I wouldn't use it older than that for an aircraft, but for noncritical uses
>I have a can that I've been using up gradually that is at least 15 years old
>and still seems to set up fine.
Thanks, J. FWIW, I saw a detailed instruction sheet for a similar
product (water-activated powdered precat urea formaldehyde) that said:
:Note: If powder wont easily and readily dissolve into the water, or if the mix appears sandy
:and/or grainy, the product should not be used. These working characteristics provide a built-in
:safety check signaling the powder has passed its shelf life.
>
>Ace Hardware lists it online, but only in 4.5 pound containers for over 20
>bucks--you might want to call around and see if they have the one pound size
>in the stores.
I found it at the 5th Ace I called. Suspicious of the shelf life
already used on the store's shelves, given the dust on the container,
but decided to go ahead based on your experience and the advice quoted
above. (and my boldness was helped by the whopping total of $6 at
risk<g>)
>I haven't used it so can't say how good it is, but try
><http://www.woodweb.com/knowledge_base/_Spreadsheet_Calculation_Program.html>
>which is an Excel spreadsheet that purports to calculate springback for
>laminations.
Lots of neat stuff in that spreadsheet. Thanks.
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.
"alexy" <[email protected]> wrote in message
news:[email protected]...
>I am getting ready to do a bent lamination, and have questions about
> adhesives and springback.
>
> I have heard that urea formaldehyde or plastic resin glue is the best
> to use for this application because of the long open time and lack of
> creep once set. I am having a hard time finding it, though. I can get
> a gallon from Highland Woodworking but because of its relatively short
> shelf life, I would end up throwing away 95% of it. Anyone know a good
> source for small quantities (Atlanta area desired, but online source
> okay, too) or whether another type of glue would work as well. My
> application is not load-bearing, and in fact will be "captured" by
> another structure. I'm laminating 4 pieces of 1/8" thick poplar for
> edge banding of the inside of an elliptical arch cut in plywood.
I think the stuff you're looking for is Weldwood Plastic Resin Glue,
<http://www.dap.com/product_details.aspx?product_id=42> which is a
urea-formaldehyde water-activated dry powder FAA approved for aircraft
construction (in other words this is seriously good stuff). You can get it
online in one pound containers for about 8 bucks a pound and shipping. Two
reliable sources are Aircraft Spruce and Specialty
<http://www.aircraftspruce.com/catalog/wppages/weldwood.php> and Jamestown
Distributors
<http://www.jamestowndistributors.com/userportal/show_product.do?pid=2432&familyName=Weldwood+Plastic+Resin+Glue&BASE>.
It used to come in pint cans but now the smallest seems to be a pound. I
don't know what the real shelf life is--officially it's "1 year minimum" and
I wouldn't use it older than that for an aircraft, but for noncritical uses
I have a can that I've been using up gradually that is at least 15 years old
and still seems to set up fine.
Ace Hardware lists it online, but only in 4.5 pound containers for over 20
bucks--you might want to call around and see if they have the one pound size
in the stores.
Read the instructions carefully--the stuff is reasonably forgiving but it is
possible to screw it up. That part about "cannot be successfully removed
from most surfaces once set", they _mean_ it--don't wear clothes you care
about. The only way to get it off wood once it cures is to scrape or sand.
Also, when the squeeze-out sets up it's _hard_. Doesn't stick to metal
though, at least none that I've dripped it on. Nice thing is that if you
get to it before it sets you can clean up with water.
> I have a form for bending my lamination, that I made slightly
> undersize, anticipating that there will be some "springback" when the
> lamination is removed from the form. Anyone have any ideas or formulas
> for estimating how much that will be in advance, or is it just a case
> of trial and error?
I haven't used it so can't say how good it is, but try
<http://www.woodweb.com/knowledge_base/_Spreadsheet_Calculation_Program.html>
which is an Excel spreadsheet that purports to calculate springback for
laminations.
If you google "lamination springback calculator" you'll find some others.
> --
> Alex -- Replace "nospam" with "mail" to reply by email. Checked
> infrequently.
"alexy" <[email protected]> wrote in message
news:[email protected]...
> "Teamcasa" <[email protected]> wrote:
>
>>
>>"alexy" <[email protected]> wrote in message
>>news:[email protected]...
>>> Lew Hodgett <[email protected]> wrote:
>>>
>>>>alexy wrote:
>>>>
>>>> > I've thought about that, but how is it for creep? My impression is
>>>> > that UF and epoxy are better in this regard. But maybe that's
>>>> > academic
>>>> > in my relatively low-stress project?
>>>>
>>>>SFWIW, For the price of Gorilla Glue or equal, you can add maybe 10%
>>>>and get epoxy.
>>>>
>>>>There is no comparison between epoxy and Gorilla Glue.
>>>
>>> Thanks, Lew. I wonder what the trade-offs are between UF and epoxy?
>>> Sounds like you are a "fan" of epoxy, but there are always tradeoffs.
>>
>>Lew LOVES epoxy (and must have stock WestSystems). He suggests it for
>>virtually every fix where an adhesive is used. Since he works on boats,
>>its
>>a natural choice. For the rest of us, we get to use several diffrent
>>glues.
> And his love of epoxy may be well founded--in its many formulations it
> is wonderfully flexible. But I still believe that there are tradeoffs
> in selection of any construction material or technique, and I'd like
> to see some discussion to form the basis of an informed choice.
Cagle, in "Handbook of Adhesive Bonding", a well known engineering
reference, recommends UF or RF over epoxy for wood-to-wood joints exposed to
weather. I don't remember why now and my copy is not readily accessible.
However he was writing over 30 years ago and the available epoxy
formulations may have improved since then.
Personally I generally use Titebond or PU for the convenience, but if it's
mission-critical indoor and I've got a good fit I go for the UF and
mission-critical outdoor the RF.
OTOH, I've got an assembly I'm going to glue up with T88 epoxy tomorrow, the
reason being that it's outdoors, the temperature right now is going down
into the high 30s at night, and T88 will cure at that temperature
(eventually) while UF and RF aren't rated to cure below 70 and the rest not
below 50.
Teamcasa <[email protected]> wrote:
:> :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
:>
: 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.
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.
- Andy Barss
>>> "Teamcasa">>>
>>You are not. 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
> 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
>
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.
Dave
"Teamcasa" <[email protected]> wrote:
>
>"alexy" <[email protected]> wrote in message
>news:[email protected]...
>>I am getting ready to do a bent lamination, and have questions about
>> adhesives and springback.
>>
>> I have heard that urea formaldehyde or plastic resin glue is the best
>> to use for this application because of the long open time and lack of
>> creep once set. I am having a hard time finding it, though. I can get
>> a gallon from Highland Woodworking but because of its relatively short
>> shelf life, I would end up throwing away 95% of it. Anyone know a good
>> source for small quantities (Atlanta area desired, but online source
>> okay, too) or whether another type of glue would work as well. My
>> application is not load-bearing, and in fact will be "captured" by
>> another structure. I'm laminating 4 pieces of 1/8" thick poplar for
>> edge banding of the inside of an elliptical arch cut in plywood.
>>
>> I have a form for bending my lamination, that I made slightly
>> undersize, anticipating that there will be some "springback" when the
>> lamination is removed from the form. Anyone have any ideas or formulas
>> for estimating how much that will be in advance, or is it just a case
>> of trial and error?
>> --
>> Alex --
>
>Alex, For the project you describe above, I would use polyurethane glue.
>Its has sufficient open time for your project. I only use plastic resin
>glue when I need + 20 minutes to get the project clamped up.
>
>Dave
>
I've thought about that, but how is it for creep? My impression is
that UF and epoxy are better in this regard. But maybe that's academic
in my relatively low-stress project?
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.
"Teamcasa" <[email protected]> wrote:
>
>"alexy" <[email protected]> wrote in message
>news:[email protected]...
>> Lew Hodgett <[email protected]> wrote:
>>
>>>alexy wrote:
>>>
>>> > I've thought about that, but how is it for creep? My impression is
>>> > that UF and epoxy are better in this regard. But maybe that's academic
>>> > in my relatively low-stress project?
>>>
>>>SFWIW, For the price of Gorilla Glue or equal, you can add maybe 10%
>>>and get epoxy.
>>>
>>>There is no comparison between epoxy and Gorilla Glue.
>>
>> Thanks, Lew. I wonder what the trade-offs are between UF and epoxy?
>> Sounds like you are a "fan" of epoxy, but there are always tradeoffs.
>
>Lew LOVES epoxy (and must have stock WestSystems). He suggests it for
>virtually every fix where an adhesive is used. Since he works on boats, its
>a natural choice. For the rest of us, we get to use several diffrent glues.
And his love of epoxy may be well founded--in its many formulations it
is wonderfully flexible. But I still believe that there are tradeoffs
in selection of any construction material or technique, and I'd like
to see some discussion to form the basis of an informed choice.
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.
Lew Hodgett <[email protected]> wrote:
>alexy wrote:
>
> > I've thought about that, but how is it for creep? My impression is
> > that UF and epoxy are better in this regard. But maybe that's academic
> > in my relatively low-stress project?
>
>SFWIW, For the price of Gorilla Glue or equal, you can add maybe 10%
>and get epoxy.
>
>There is no comparison between epoxy and Gorilla Glue.
Thanks, Lew. I wonder what the trade-offs are between UF and epoxy?
Sounds like you are a "fan" of epoxy, but there are always tradeoffs.
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.