# Glue failure



## Dimonback (Dec 10, 2010)

Howdy-- 
New guy here, 30 year electrician and teaching myself small project woodworking. I made a couple of pieces (oak box, mitered/glued and oak mantel clock routed and glued) to ship to my parents in Oregon. No air travel involved, but both pieces had failed glue joints on arrival. I used either Elmer's wood Glue or Titebond on both pieces. Can someone give me a clue what happened? I have several pieces here at the house still that are holding up fine, and one piece whent to Bermuda with no failure.


----------



## cabinetman (Jul 5, 2007)

Dimonback said:


> Howdy--
> New guy here, 30 year electrician and teaching myself small project woodworking. I made a couple of pieces (oak box, mitered/glued and oak mantel clock routed and glued) to ship to my parents in Oregon. No air travel involved, but both pieces had failed glue joints on arrival. I used either Elmer's wood Glue or Titebond on both pieces. Can someone give me a clue what happened? I have several pieces here at the house still that are holding up fine, and one piece whent to Bermuda with no failure.



*WELCOME TO THE FORUM*

Would need to know what joinery was used and the method you used to fit/clamp the joint. Pictures would be nice.












 









.


----------



## Joe Lyddon (Mar 13, 2007)

Welcome aboard!

One thing about Miter glue-ups... it's end grain to end grain and just a plane ole glue joint usually does not hack it... The joint should be strengthened in some way like with Kehoe splines in the corners, etc. Something more than just mitered glue joint...

Just guessing at what your problem might be... 

You could get the stuff back and spline it... and would probably work out just fine.

Have a good one!


----------



## sketel (Sep 15, 2010)

I'm going to guess it has to do with humidity difference. I live in Oregon and have brought back instruments and furniture from Ohio where my family lives and have run into all kinds of problems due to the shrinkage from the change in humidity. Just to give you an idea, a humid day here in the summer is 30%. If they live in eastern oregon, it is even drier.


----------



## Dimonback (Dec 10, 2010)

The pieces were all built in Las Vegas, where a humid day in the summer is 17%. It sounds as though the glue simply evaporated away, which doesn't make sense to me. I just don't know. Here's some pics, embarassed to show them as I am:

The box was mitered, with routed channels to install the top and bottom plates, and glued on all mating surfaces.

The clock was routed top and bottom to install the center plate/clock mount. I tried dowelling the posts in but missed the holes. I am pretty sure I shot a couple of brads in from the bottom to hold the posts, but the top most likely came off. Thanks in advance for any help here...


----------



## woodnthings (Jan 24, 2009)

*Splined Miters*

Like these from Everyman Show, increase the glue surface area.
 
or these from My Photos, kitchen cabinets album: http://www.woodworkingtalk.com/members/woodnthings-7194/albums/kitchen-cabinets/










There is an end grain to end grain issue on a miter. While it's not a 90 degree joint, like a butt, it's at 45 degrees so the same issues apply only a little less. The spline increases the glue area and offer greater strength, especially in a door frame where it's much more prone to stress than in a small box. I don't know if you already were aware of this or if it's too late to help now? Maybe in the future? :blink:
One Last thing on a spline. There is the *easy* way to make them, long grain running the entire length of the spline, by just ripping slender strips on the table saw.
Then there's the *correct* way cross grain running across the joint. Cross grain will not split down the length of the joint like long grain, but they are harder to make and find in long lengths. You may have to make shorter pieces and use them end to end.  bill


----------



## Tony B (Jul 30, 2008)

*Spline Material*

The major problem is with the miter joints not having any real glue strength to be of value. This has already been covered so lets jump to splines.

I use plywood for my splines. In most cases, 1/4" Luan is suficient. If the spline will be noticable, stop it short by 3/8" or so and use a solid piece of wood for the showing end.


----------



## jack warner (Oct 15, 2010)

use a better glue like an epoxy or gorila glue and clamp. i use gorila glue and have never had a joint fail.


----------



## cabinetman (Jul 5, 2007)

A splined miter joint would have worked well. It sounds like you didn't have sufficient glue and/or the clamping wasn't properly done.












 









.


----------



## sketel (Sep 15, 2010)

While the suggestions given are good and would improve joint strength, you can get a miter joint that is strong using titebond II. You can apply glue to both sides of the joint, wait for it to soak in a little then reapply glue and make sure not to over-tighten your clamps.


----------



## TimPa (Jan 27, 2010)

i pre-assemble my 45 degree cut door trims/casing using titebond II and a couple of brads. you can hold the entire assembly up by one leg. what i have found to cause glue joint failure is: wrong glue type, cross grain situation, inadequate glue amount (esp on end grain situations - what sketel said), too much pressure squeezing glue out of joint, and, humidity changes. eliminate what you can.


----------



## jack warner (Oct 15, 2010)

thats why i like garila glue you can tighten clamps all you want. the glue expands into the wood


----------

