A lot of people tell me
if your joints aren’t very tight you can just use Gorilla Glue because
Gorilla Glue expands to fill the gaps. Well, I’m not so sure
that’s such a good idea. So, let’s try this out. I’m gonna
glue these 2 pieces of wood. And I’m just gonna wipe this with
a moist piece of paper towel to make sure I’m gonna have
some moisture in the joint. So, certainly enough that this
will fill the gap all right. And, I’m going to put these plastic shims on the
corners of the joint. And that will make sure there’s gonna be
a slight gap when I clamp this together. And now the other
piece of wood on top. So I’ve got enough glue
in there to completely fill the joint even
if it doesn’t expand. But, I’m assuming
that is for the better. So, I gave this glued joint
a whole week to set. And, as you can see
it’s expanded by quite a lot. The question is really
how strong is this joint? So, let’s give it
a scientific test. (Grunting Sounds) Actually, I was just kidding.
Let’s really try this. (Snap) Not very strong at all. So what makes this glue so weak? I think the problem is
that it expands. And it expands into a foam.
And foam is just not a very good glue. So, for instance, here is
a dab of glue that I put on this piece of wood. I can just break this stuff.
Look at that, it’s just bubbles. So, why do I want to
flog a dead horse? I already know Gorilla Glue
sucks with gaps. The problem is, before I did my breaking
test by hand I prepared a bunch of samples. So I might as well test those in
my apparatus to get a reading. Each joint is 4 by 4 centimeters And I’m extending that out here because
I didn’t want to waste that much wood to 20 centimeters. And I’m applying
the force with a bottle jack which is on a bathroom scale. And I’ve got a camera to record the weight
just in case I miss the maximum reading. And I’ve already adjusted
to zero on here so that it’s zero
with the jack already on it. All right.
Here goes sample number 1. This is a gapped
Gorilla Glue joint. So, pumping very carefully. 5
10 12 15 15 It doesn’t go over 15. Yeah, I can see it yielding. Or hear it yielding. Yeah. So, about 15 pounds
for the Gorilla Glue. All right.
This is sample number 2. It’s Gorilla Glue without a gap. And I have to put my hand
on there while I’m pumping it because some of these joints
are so fragile. Just the part falling
would wreck it. I think this one might do better
because there’s no gap in it. 15
30 205 210, no not quite. 215, wow. 220 220 I can hear it crackling now. It’s about to go. 230 Not holding. Yeah, I can’t count that 235. (Crashing sound) Holy shit. Joint number 3 Yellow Elmer’s Glue, with a gap. 210 210 (Crashing sound) So close. This sample number 4.
Yellow Glue with no gap in it. 190 195 Uh oh. Is it gonna pop?
I think so. (Crashing sound) Yup. Sample number 5. Gorilla Glue with no gap. So, this
one could do fairly decently. 200 205 205 And let’s wait
for that one to pop. (Pop) Bang. It’s sample number 6. Is yellow glue
with no gap in it. 180 185 It’s coming. (Crashing sound) Whoa ho. This pin up here is very important,
just to make sure I apply the force at the right place. Sample number 7.
Yellow glue with a gap. 205 It’s a coming. (Crashing sound) I have to be careful when
I clamp these pieces on here. And now pushing this part
of the glue joint. Because that might bias it
one way or the other. All right.
This one’s gonna be an easy one because it’s a gapped
Gorilla Glue joint. So, I have to crank it
very carefully. 10 15 Here we go. Well, 15 pounds again. At least it’s consistent. Joint number 9.
Gorilla Glue without a gap. (Pop) So, this last one is another
Gorilla Glue joint that’s gapped and I know it will do
pretty poorly, so I’ll rely on my own brawn
and brute strength. Hi-yaa. I think that reads about
15.35 pounds. Yeah.
(Laughs) Now, there’s no question that the gapped
Gorilla joints performed terribly. But, when I tabulate the numbers
I actually found that the ungapped Gorilla Glue joints were a bit
stronger than the ones with yellow glue. So, Gorilla Glue can make for
a fairly strong joint. You just have to make sure
your joints are really precise.