OK at 13:30 EDT the race started.
I glued up a 90 degree face to face joint (cross) using 2 glues in 3 conditions
Rough sawn hard maple face (each side)
Milled hard maple ...
Rough sawn western red cedar ...
Yellow interior carpenter glue
All clamped up
at 13:30 tomorrow I will try to break them all
Who wants which in the pool?
Sort of makes me want to go rent a recording strain guage. ;-)
Now here's where my lack of knowledge about glues is showing. Besides the
waterproof part, I thought one of the differences between Poly and PVA - I
*think* that's the two categories we're talking about here - was setup
time. I was hoping to see someone post about using Gorilla glue when it was
a complicated glue-up and it gave them more time to get all the joints in
place. I can't remember what David Marks uses when he wants a longer setup
time, but I think it was dark.
Dunno what Mr. Marks uses, but traditionally you'd use hide glue.
Titebond makes one. I know there's also a more modern alternative.
While looking for it, I found this interesting chart comparing the
properties of various glues:
I've got my own test going now. I built some planters and benches in
western red cedar three years ago. About half the joints with yellow
glue (tightbond 2), the other half with gorilla glue. The finish on
the planters is white latex paint, the benches are finished with
Sikkens Cetol 1
After two winters and lots of weathering, I see no sign of joint
How 'bout epoxy?
Built some planters many years ago (~15) outta pine. Used epoxy;
painted them with latex (I think) paint. Even epoxied little daisies
on the fronts. Still lookin' good and holding together.
I like epoxy. Sometimes it seems like overkill, and since it's
expensive, I'd rather be sure the glue job is big enough to use all
that gets mixed. BTW, these remarks pertain to the West System with
those pumps that automatically dispense the correct proportion. They
make a pretty good amount of mixed epoxy even on 1 push of the pump.
On Fri, 22 Aug 2003 13:19:06 GMT, firstname.lastname@example.org (Renata)
If you are gluing them cross grain they all will eventually fail as each
board swells or contracts with climate changes.
For the time being, they all should be strong. Probably the milled maple
will be the best scenario.
These glue joints are only going to last 24 hours and however minutes it takes
me to break them. I am still waiting to see some wood damage, where the joint
was truly stronger than the wood.
My guess is that the western red cedar is going to be the one that presents
that scenario. (torn wood) My bet is the sawn surface will hold better than the
milled one, simply because there is more surface area on a microscopic scale.
On 21 Aug 2003 23:25:37 GMT, email@example.comGreg (Gfretwell) wrote:
If I may go off on a slightly different track, this reminds me of a
question I've been meaning to ask here for a long time.
For the strongest glue joint, is it better to have the surface rough
or smooth? I've always assumed a rough one (within reason) would be
better, as Greg suggests. But several sources I've seen state quite
emphatically that "smoother is better".
Not quite. Whether or not you need penetration depends on the surface energy
in the bonding materials. High surface energy means lots of strength in the
Low energy means less strength. If you want to glue with a weak bond, then you
want to increase the surface area - rough and porous is good. If the bond is
then you can use less area and a smooth surface suffices.
Glues like polyurethanes make things interesting since they are strong as long as
they don't foam. Hence, expanding into an open area doesn't buy you enything
and roughness doesn't work as well. Epoxies, OTOH, are strong and will do a good
job at filling up spaces. Cyanoacrylates don't do a good job at filling up
but are really good at bonding smooth surfaces.
The surface preparation depends on the material, the glue and the desired
I get the best results when I read the label on the glue and follow the
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