Glue Creep--How to avoid?

Hiya All, Awhile back I posted about a redheart box I had built that I experienced glue creep on. I used Titebond II and felt it had fully cured although the temp during curing was right around the lower limit. Ok, so I attributed the creep to the temp.

I just finished two cherry nightstands with glued up tops (panel). These tops were glued up and left to cure in relative warmth (85 or so) and prior to finishing, they sat for prolly 6 weeks. Yup, 6 weeks. Took me awhile to get these projects done. Anyway, I finished with a very thin coat of watco natural and about 8 coats or so of shellac. Then rubbed out with limestone, rottenstone, etc.... Looked gorgeous.

So they've been in the house now for about 3 weeks (temp is a little cooler say around 75-80) and low and behold it appears I have creep. Right where the pieces in the panel are edge glued, I'm getting a ridge. Can't really see it but can feel it. I used titebond II again. This is coming out of a gallon container that is perhaps 3 months old. Glue seems fine, adheres well, and doesn't appear to have "spoiled".

So my question, just what the heck can I do to avoid this in the future? I've liked titebond to date but honestly if this is what it does, then I'm gonna have to find an alternative. I see poly has been well received on the rec. in terms of creep so maybe that's it. Either way, I'd like to know if there's a way to avoid creep with the titebond II. I plan to write the company cause I'm pretty ticked off about this. I'll prolly never get the tops looking good if I go back and knock these edges down and then try to match the finish so you can understand my ire.

Anyway, thanks for any inputs. Cheers, cc

ps. forgot to mention, I'm in NM and avg. humidity has been between prolly 10-15% for the past 8-10 weeks (from glue-up to final rubout).

Reply to
James Cubby Culbertson
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Sounds to me like you are building with relatively wet wood and then taking it into a relatively dry environment. The wood shrinks slightly but the hard glue line does not. Do you know moisture contents or relative humidifies? Is the wood shifting, or is the glue line high on both sides of the panel? Where are you located? Glue creep is normally caused by force or stress; either of which would normally exist in a panel.

Reply to
Alan Bierbaum

Well here is another guess .

seems to me you should send a copy of your post to titebond and see if they have any suggestions .

Even tough some creep is possible ,really there is little reason for its cause in this case providing the wood on either side of the glue joint is free to move , i.e. the joint is stress free .

One thought comes to mind [although your first example should nullify this argument where you left it unfinished for 6 weeks ], sometimes excessive clamp pressure can cause problems . At times when the joint is not a perfect fit,the edges do not quite fit it is tempting to over tighten to obtain the desired squeeze out . Particularly with wide boards more pressure is required to obtain this result . while this is fine for the troubling areas of the joint it causes glue starvation in other areas which fit correctly .Inasmuch that the perfect requires a glue film between surfaces to perform correctly ,this might be at least a contributor to the problem .

The only other suggestion to the cause might be tightbond being water based causes a marked increase in moisture content locally which obviously would take some time to stabilize to that of the surrounding wood .Living where you do the material moisture content should be pretty low ,probably something like 5% or less I would guess. However I would have thought 6 weeks before finishing should have been ample time to stabilize .

So my suggestion is to get as perfect a dry joint as you can and that should result in low clamp pressure and lower joint residual stresses .It is the stress that causes the deformation in any medium....mjh

Reply to
Mike Hide

Update to my post. I missed part of the original post last night when I replied. I missed the PS and the word either appeared instead of neither in the last sentence.

Do you have a swamp cooler in either the house or shop?

Reply to
Alan Bierbaum

O I think most creep is caused by wood that is not dry enough. You can also use a poly glue to eliminate it.

Reply to
Steve Knight

I agree with Steve, and I just read about this in a book a few nights ago. If you are gluing two woods with different moisture contents (such as one board air-dried and one board kiln-dried), whenever they acclimate to their surroundings the will expand/contract to different amounts. The book was discussing the importance of acclimating wood to your shop environment for a period of time before working with it.

david

Reply to
D K Woods

You're reading the wrong book if you think there's a difference in stability.

Check Hoadley and others for information. X % is X % regardless.

Reply to
George

Oh I wasn't referring to stability. I'm saying that if you perfectly align and glue two pieces of wood, one at 8% and one at 11%, then after a few weeks for the wood to acclimate to the environment they will no longer be perfectly flat. Since the wood is at different moisture levels, they react differently to environmental humidity and will expand/contract a different amount. The result is small step in the wood. Here's what the book has to say (Nick Engler's "Woodworking Wisdom", p. 13):

"Joinery that has been planed and sanded flush sometimes develops 'glue steps' -- tiny changes in the surface levels from one board to another. These are especially noticeable in tabletops where two or more boards are joined edge to edge. The common misconception is that these steps are caused by improper gluing technique, but they are actually the result of uneven wood movement. Sometimes a craftsman fails to shop-dry the lumber. The individual boards have different moisture contents when they are joined, and the moister boards move more than the drier ones. Or the craftsman glues flat grain to quarter grain, opposing tangential movement to radial movement. The flat-grain edge moves at a different rate than the quarter-grain edge. In both cases, a step results."

Now the OP did say that he waited six weeks after glue up so this doesn't sound like the perfect answer to his problem, but I figured that sharing the wisdom might help the OP out anyway.

I would like to check out the Hoadley material that you mentioned. I'll see if the library has any of his titles.

david

Reply to
D K Woods

Comments in inline below:

I would agree. Paxton sells dry wood and it sat for about a year in your envinronment.

Agreed

I have a big problem with this statement. Shellac will not stop moisture; it just slowes it down (more than many other finishes). I remodel kitchens for a living (furniture is right now a part time job; full time again after this year). Here in the Denver area (about as dry as it is there) we run into a problem with swamp coolers. When a pair of doors is hinged so that there is a gap in the center (no stile) we normally leave a 1/16" gap; when the customer has a swamp cooler, we have to leave a 1/8" gap to prevent the doors from swelling shut. Most domestic hardwoods have similar movement with moisture; about 1/4" per foot, across the grain, between 6% and 12% moisture content. Four 2 1/4" door stiles will move about 1/8" between ambient (or air conditioned) and swamp cooler conditions. This process usually takes several weeks and happens with all finishes. This *could* be your problem. Thickness movement is less than across the grain; but the wood will move in thickness. If your joint is such than the grain is very flat on one piece and almost vertical on the other piece; you

*will* notice the difference between ambient (dry) conditions and swamp cooler (wet) conditions. You can feel a difference of only 1 or 2 thousands of an inch (you may not see it though)

OK, good

No; baring a bad batch; this is great glue. (I have never heard of a bad batch, but it is possible.) We buy TB II in 5 gallon jugs, which only last a week or two and have used it for over ten years with no problems. I use TB and TB II for my personal work and buy several gallon jugs per year; again with no problems.

Exactly how is your joint mismatched (mechanical description from both sides of the panel, if you can). You now have my curiosity awake from a dead sleep.

Reply to
Alan Bierbaum
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Here's some food for thought, Jim. I'm a neophyte at fine woodworking...so take this with a grain of salt...

Consider using the Kreg tool for pocket joinery. I've used it several times now...and the joints are super tight and instant. They suggest that glue also be used...but the joints are tight enough even without any glue.

I have never had a project sit around for any long period of time, though. I just got my first ever major project done a few weeks ago...and I did some of the joints with and without glue. But all the joints are super tight.

Again...just another viewpoint.

Good luck.

Have a nice week...

Trent

Follow Joan Rivers' example --- get pre-embalmed!

Reply to
Trent©

What is the shelf life of TB II? I have some that has been around for several years that I still use. Am I headed for trouble?

Grant

Mike Hide wrote:

Reply to
Grant P. Beagles

Stay out of the adhesives aisle at Home Depot?

-- Ernie

Reply to
Ernie Jurick

I'm new here, Bob. Is your statement really true?...or is it just an opinion?

I thought that, once a glue up is done (like in a table top) the glue is as strong...or stronger...than the actual wood. I could see the wood possibly cupping. But I wouldn't expect one plane to move in one direction...and the other plane to move in the other direction.

I thought the two planes became ONE plane.

Just trying to learn...

Have a nice week...

Trent

Follow Joan Rivers' example --- get pre-embalmed!

Reply to
Trent©

I was wondering about that too. I have been told that while white glue stays flexible after setting, yellow glue does not. Perhaps the post was a typo, or my source might have been incorrect.

david

Reply to
D K Woods

Glad that your problem is solved and that it does not involve major work to fix. You might want to spend some more time reading up on wood movement with moisture changes. There are any number of good book (Hordsley ? spelling, is a good one). Understanding wood movement will greatly reduce your future problems.

Reply to
Alan Bierbaum

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