# Sudden Problem with glue joints on end grain cutting board



## chef57 (Feb 2, 2017)

I am wondering if anyone has any experience with my problem.

I've built about 13 or 14 cutting boards for friends and family over the last 6 months, without a problem. However, the last 2 cutting boards I built have done something that is truly puzzling. After sanding completely and sitting overnight the joints rise ever so slightly. Then I sand again and let it sit over night and the joints rise again.

My process is; first I glue the ripped pieces together and wait 24 hours. Then i run the board through my planer. Next I square one end and continue crosscutting the board. Naturally I turn and glue the crosscut pieces together, and naturallly I am using clamps and cauls to during the glue up. I allow the glue to cure another 24 hours and then I plane the surface again.

Next I square the board off and begin sanding with 50 grit paper until I have a smooth surface. Next I move to 80 grit, then 120 grit, Then I route the edges and the grooves. Next I sand the routed edges and grooves by hand with 80, 120, and 220 grit paper. Finally I sand the surface and sides one more time with 220 grit paper. Then I oil the boards with mineral oil, and finally a mix of mineral oil and beeswax.

This is the process I go through with every board I have made. Same method, same process. For some reason the last two boards that I made have a very slightly raised joint line on the two flat surfaces. And It is every joint. It's almost like the glue joints are swelling up.

I would love to know what you folks think.

Thanks


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## Loren (May 30, 2008)

What type of glue are you using?


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## Unknowncraftsman (Jun 23, 2013)

Sounds like glue creep I bet he's using Tb3. I thin down glue for this very reason espnon hard maple cutting boards.
It's nearly impossible for me to squeeze out the glue with my clamps so I usually get a thick glue line that I don't like.
Or maybe my glue is too old.
I might be way off here and that's ok with me.
It sounds like your meticulous with your milling and flattening ,so that's good.


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## wormil (Nov 19, 2011)

I've had TB3 shrink and do the opposite. Not sure about swelling glue joint unless it's polyurethane glue but that happens right away.


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## JBrow (Nov 18, 2015)

chef57,

I have noticed very slightly uneven joint lines of edge grain to edge grain glue-ups, like table tops. I have made no end grain cutting boards but perhaps this is the explanation:

I wonder whether working in your 70%+ coastal humidity that you may be flattening/smoothing your two most recent glue-ups before moisture content around the glue line has equalized. If the wood fibers at the joint line are still swollen from excess moisture (due to application of a water-based glue), excess wood could be unknowingly removed when the end grain is sanded smooth. As the glue-up rests and the joint line wood fibers lose moisture, a slight depression only at the joint line could then result. The coastal high humidity could require an extended period of rest after the glue is cured before smoothing. The period of extended rest would allow the joint line wood fibers to return to moisture equilibrium.

If your successful cutting boards were made when humidity was lower or the smoothing was delayed beyond 24 hours, then this explanation may be correct. But then since these recurring uneven joints are on the end grain, I am not sure. Also if the glue is not water-based, then I have wasted words since moisture content at the joint line is not increased by the glue.

Here is a paper that discusses glue-ups. Check out page 7, at "AFTER GLUING"…

http://www.jamesltaylor.com/sites/default/files/downloads/Book_on_Gluing.pdf


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## Kazooman (Jan 20, 2013)

JBrow: Good idea, and something I have wondered about. That is, the moisture in the glue swelling the fibers of the wood I have so carefully flattened with precision swelling things during glue up. However, the chef said that he has raised glue lines, not depressions. Seems odd on an end grain board where changes in the thickness dimension should be minimal with moisture content. It does sound like there is something about the glue creeping from the joint, although I have never seen this myself. I have always used "good old" TB2 for my boards.


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## JBrow (Nov 18, 2015)

Kazooman,

I thought about the two points you raised as I was composing my above post; and on both accounts you may well be correct. But here is my thinking, for what it is worth.

chef57 indicates the joints rise ever so slightly but does not say how he determined the uneven joints. If the uneven joints were detected by touch then a depression could leave the impression that the joint line has risen if the affected area is very narrow. A depression would likely be equal on both sides of the end grain board at the same joint. But if one strip of end grain is proud of an adjacent end grain strip on one side but the adjacent end grain strip is proud of the one end grain strip on the opposite side, it sounds more like a glue creep problem.

I can image that swollen wood fibers at a glue line on the end grain at the surface could be squeezed and swell proud of the surface. When these swollen fibers are removed from sanding and moisture equalizes at the glue line, a depression could form. If no depression exists, then my notation has to be discounted.


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## bigJohninvegas (May 25, 2014)

Bad Glue, wrong glue, or….. Are you using kiln dried wood? 
maybe a high moisture content in the wood. 
But I would think a glue issue before all else.


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## chef57 (Feb 2, 2017)

> What type of glue are you using?
> 
> - Loren


I am using TB3 or Titebond III.


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## chef57 (Feb 2, 2017)

> Kazooman,
> 
> I thought about the two points you raised as I was composing my above post; and on both accounts you may well be correct. But here is my thinking, for what it is worth.
> 
> ...


When I sand down the boards the surfaces are literally smooth as glass. They are that way on every board I have made. The seam or glue line feels slightly raised when I run my finger over it. But it is consistent on both the crosscut lines and the rip lines. However there is one small difference, on the older of the two boards the edges have the same anomoly, while the newest board has perfectly smooth edges. By edges I mean the sides of the board.

The only differences are that the last two boards were made within the last month and I live on the Texas coastline. But the humidity on the Texas coast is, by and large, 60 to 80 percent year round.


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## chef57 (Feb 2, 2017)

> Kazooman,
> 
> I thought about the two points you raised as I was composing my above post; and on both accounts you may well be correct. But here is my thinking, for what it is worth.
> 
> ...


I seem to have made this more confusing. I should have said, When I sand the boards they come out as smooth as glass. The next day when i check the board all of the seams or glue lines are slightly raised.


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## Unknowncraftsman (Jun 23, 2013)

It's just sounds like thick glue lines.One more thing that helps is to spread you glue with a notched piece if wood or a roller.I know everyone is afraid to thin glue down,but if you do a test piece you might change your mind.
Tite bond 3 has more solids then 2 or 1 so it does take a lot if clamping pressure so thinning helps.


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## wormil (Nov 19, 2011)

See my post above, TB3 is known for shrinking. Are you sure the glue is raised?


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## Loren (May 30, 2008)

Aliphatic resin glue does go bad with
time. Manufacturers say it's only good
for a year or so but I've found it keeps
for longer than that. In any case, when
it goes bad it can get thicker and stringy,
not cure properly, maybe smell a little
off.


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