Darryl Keil Last Activity 2025-09-09 11:09 AM
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matt campbell

Posts: 9

Joined: 2005-12-22
Location: anchorage,alaska

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Subject : glue problems
Posted : 2005-12-22 3:46 AM
Post #32651
I used unibond 800 laminating four 3/4 thick by 4 inches wide walnut boards.The joints are slowly opening up.Temp was seventy five degrees in shop,clamped for 13 hours with hand screws placed every 2 inches.I used a roller to apply glue on both sides.The mixture of glue was 1 cup powder to 1 quart liquid.The feet recieved a full mortise tennon in the center after about two and a half days.The shop has been rather dry,making most of the wood around six percent moisture.I like the open time of the glue so I would like to find out the problem.


 
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Darryl Keil

Posts: 1455

Joined: 2003-05-22
Location: Maine

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Subject : RE: glue problems
Posted : 2005-12-22 8:35 PM
Post #32654 - In reply to #32651
Matt,

This sounds like what happens when either the wood or the room is not up to temperature. You mentioned that the room was at temperature. Is there any chance that the wood itself was colder when you clamped it? Although the temperature of wood and room should be warm throughout the clamping process its most important right in the beginning when the catalization is beginning.

What do you mean by "the feet received a full mortise tenon in the center after about two and a half days"? I dont understand this.

Sincerely
Darryl Keil


 
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matt campbell

Posts: 9

Joined: 2005-12-22
Location: anchorage,alaska

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Subject : RE: glue problems
Posted : 2005-12-22 9:46 PM
Post #32655 - In reply to #32654
The walnut was brought in two weeks prior to working.Shop stays about 65 to 70 degrees all the time.I am not positive the wood was a perfect 70 degrees.I can only guess it to be 65 to 70.The table is a trestle style.Where the leg panel passes through the foot.


 
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Mitch

 
Subject : RE: glue problems
Posted : 2005-12-23 10:58 AM
Post #32658 - In reply to #32655
Is it possible that too much clamping pressure squeezed out the glue, leaving the joint glue starved? Is it opening up in any particular area. i.e. between board 1 and 2, or just one side?



 
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matt campbell

Posts: 9

Joined: 2005-12-22
Location: anchorage,alaska

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Subject : RE: glue problems
Posted : 2005-12-23 2:41 PM
Post #32660 - In reply to #32658
Does unibond glue need less clamping pressure than titebond?Yes the joints are all showing signs of release on both sides of the mortise.But have never had this problem with titebond even when I have made the tenon to tight.I did test the joints with the cutoff scrap by breaking them in line with the glue joint.The cutoff with unibond broke with a few fibers on the glue while the titebond broke a half inche away from the glue line.


 
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MAB

 
Subject : RE: glue problems
Posted : 2005-12-23 3:38 PM
Post #32661 - In reply to #32660
So it seems that the force of the tenon is stronger than the glue line. I've used unibond for veneer, so strength is unimportant. Is unibond supposed to be stronger than titebond? Based on your experiment it seems like the unibond does not adhere to the wood as well as titebond.

Looks like you have to rip it and reglue (with titebond). Better that you found out now than after the table was assembled and put into use... Check out some of the other "titebond" glues:

http://titebond.com/ProdSelectorTB.asp?pscat=2


 
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Darryl Keil

Posts: 1455

Joined: 2003-05-22
Location: Maine

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Subject : RE: glue problems
Posted : 2005-12-23 9:11 PM
Post #32666 - In reply to #32660
Matt,

Well, it sounds like temperature was not an issue. The other thing that I suggest when using Unibond 800 for solid wood is to make sure you have a sanded surface rather than a planed surface. Unibond 800 penetrates somewhat differently than a yellow glue and requires more "tooth" in the gluing surface.

I'm still not sure this is the problem but its hard to sleuth this out thoroughly without a back and forth phone conversation.

Sincerely
Darryl Keil
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