# Gorilla Glue failure



## cjwillie (Sep 6, 2011)

About a year ago I repaired a chair for a friend. He's a big guy, 6'4" about 300 lbs. Both rear legs were toast so I had to turn two new ones. Because the mortices in the seat bottom were tore up, I enlarged them to get to solid wood and made the tenons on the legs larger. It all went together well with no problems and all joints were tight. I had recently bought my first bottle of Gorilla Glue and figured it would be perfect for this job. The chair was solid so I gave it back to him. Monday he brought it back because all of the joints had loosened and the chair was now wobbly..

I managed to get it all apart with no further damage but it became apparent that the glue was the problem. All of the joints had become loose from everyday use. I reglued everything with Titebond II.

My question is this: is gorilla glue the right glue for this application or should I have used the titebond instead? I have used gorilla glue on several other projects since with no problems. Hopefully this is the only problem I'll have with it. Thanks, Willie


----------



## johnstoneb (Jun 14, 2012)

I would want to know how he is using the chair. I have used gorilla glue on chairs and had no problems.


----------



## bigblockyeti (Sep 9, 2013)

I have had zero applications where Titebond II could have been superior to Gorilla glue.


----------



## ChrisK (Dec 18, 2009)

Where the joints in the chair big enough to let the glue foam? If the glue foams it has very little strength. I also do not use extra moisture on wood since it tends to cause the gorilla glue to start setting to fast and over foam. I use extra moisture sparingly on metals and foams. But the surfaces need to be stiffly clamped so the glue does not force the parts apart when it starts to cure.


----------



## Redoak49 (Dec 15, 2012)

I have never had a gorilla glue joint fail…it is just the opposite.

How tight were the joints before you glued them. They should not be loose but if too tight, the glue will not stay very well.


----------



## BillWhite (Jul 23, 2007)

Gorilla PVA or urethane?
Kinda hard to know without a complete description.
Bill


----------



## cjwillie (Sep 6, 2011)

It was urethane glue. The joints were tight, new, and free from previous glues. I have done similar repairs using Titebond and never had a problem. As far as I know, the chair doesn't get abused, it's used at the dinner table. He may lean back in it, which is probably why he broke it in the first place. Both of the original back legs had to be replaced.

I haven't done a lot with this glue and was wondering what could have caused the failure. Everything was prepared like I normally would using Titebond. I followed the directions on the bottle and as far as I know I did it right, but I've been wrong before! I'll use up what I have but I'm not sure I'll buy any more.


----------



## BillWhite (Jul 23, 2007)

I don't use urethane glue. Consider it much ado about nothing.
PVA glues are my choice. Not gap filling that I can tell but, if you've got a bunch of gaps, you've got a joinery problem.
Gorilla brand has a good PVA glue. Shame that they don't create some marketing that differentiates. Kinda like Scotch tape. They have so many types, yet all are called Scotch.
Bill


----------



## DrDirt (Feb 26, 2008)

I don't use Polyurethane glues - the wetting is important as well as the gap.

Polyurethane won't handle gaps at all - it expands where your glueline is basically just polyurethane sprayfoam.

You mention a tight glue line - so it should not be an issue - all the glues out there should be stronger than the wood itself.


----------



## crank49 (Apr 7, 2010)

I can't believe anyone would say Gorilla polyurethane is their glue of choice over Titebond I, II, or III.
It has virtually no shear strength.
It's only use as far as I can tell is where very little strength is needed, but it needs to be waterproof.
And, there are much better choices for waterproof glues, most of which are much less expensive.


----------



## pintodeluxe (Sep 12, 2010)

I like TB II in most applications. For chairs I sometimes use TB II Extend, because it offers 20 minutes of open time.


----------



## NoThanks (Mar 19, 2014)

I don't use gorilla glue. Not as strong as titebond in my opinion


----------



## eccentrictinkerer (Feb 9, 2010)

Where strength is needed I avoid Gorilla glue. I've tried it at least a dozen times with little to no success.

Matthias Wandel tested the stuff. Also un-impressed.

Link

https://www.youtube.com/watch?v=MUWu-N85oXM


----------



## JAAune (Jan 22, 2012)

Gorilla glue is more expensive, messier, harder to spread and still requires tight fitting joinery just like PVA glues so it's not a great choice for general application.

I've used the urethane stuff when I need to work in low ambient temperature, assemble moist wood or just want to do a repair on a veneer bubble and want something that has better tack than PVA.


----------



## TheFridge (May 1, 2014)

After looking at matthias wandel of woodgears.ca glue breakdown tests, it seems gorilla glue had some of the best yet some of the worst results. Urethane glue is neat stuff but I'd rather old faithful myself.


----------



## Pono (Mar 10, 2012)

16 years using gorilla glue barely any failures and they wernt the glues fault.Did you say 300lbs wow big boy i have a table i made at my house friends 450 he leaned on it and snap no matter what glue.


----------



## Pono (Mar 10, 2012)

thats 16 years and over 10k products i love gorilla glue


----------



## DrDirt (Feb 26, 2008)

> 16 years using gorilla glue barely any failures and they wernt the glues fault.Did you say 300lbs wow big boy i have a table i made at my house friends 450 he leaned on it and snap no matter what glue.
> 
> - Joseph Jossem


True he is a big boy - but I am picturing the turned rear legs - coming into the seat….. doesn't seem it should be a glue failure, but maybe the design I have in mind is not right. I am reading the turned rear leg going into a round mortise in the seat like this….

From the OP description of "Mortise into the* seat bottom*" and turning legs. - - 








I don't see how you have glue failure in such a joint whether Gorilla or Titebond after 1 year.


----------



## RogerInColorado (Jan 18, 2013)

Most modern glues are stronger than the wood they bond. A failed glue joint is likely either a bad joint (not tight fitting) or a bad batch of glue. I reserve Urethane glues for dissimilar materials, so I don't use them much. My go to for real PITA jobs is a good two part epoxy. In this case, you may have cleaned the joint of old glue and contaminants, but maybe not as good as it needed to be or maybe it had been "polished" with a dose of silicone. We all know nothing sticks to silicon impregnated polishing products. I'd reassemble with a fox joint wedge and some epoxy and be done with it.


----------

