# cutting boards - glue edge breaks off



## grenger (Mar 8, 2009)

ENDGRAIN boards

The first glue up is done then I cut the strips (1 1/4) for the endgrain board.
Sometimes some strips will break an the glue edge. can anyone help me with this.
I am using titebond III glue.

is it because i over-tight my clamps at the first glue up and the glue got squeezed out.

thanks
ps. I hope you understand my question. I am french Canadian and sometime have problem with the language.


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## wormil (Nov 19, 2011)

You may find this interesting.
http://woodgears.ca/joint_strength/glue_methods.html

In short, yes you can over clamp and weaken the glue joint. Are you allowing them adequate time to dry? TB3 takes 24 hours to cure. Applying glue to both sides of the joint or only one? Under what conditions are the glue joints failing? Wet? Dry? Dishwasher?


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## grenger (Mar 8, 2009)

it breaks when i cut the strips on my table saw. I apply only glue to one side as per cutting board construction i have seen here.

I think it my be that I over tight too much when clamping.

thanks


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## Dusty56 (Apr 20, 2008)

What species of woods are you trying to glue up ?
How old is the glue and how are you applying it ?
How much time do you allow it to dry / cure ? Temperature of room and glue ?
Yes , you can squeeze too much glue out of the joints by over-tightening the clamps.
If you have to apply that much pressure to bring your boards together , then something else is wrong with your methods.


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## Betsy (Sep 25, 2007)

Over tightening the clamps is likely - but also using too little glue could be an issue. Don't be a gorilla when you are tightening the clamps and make sure to have a small bead of squeeze out of glue-- then you'll be sure to have a good joint.


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## grenger (Mar 8, 2009)

the wood is PADAUK, SHEDUA, maple.
glue is new (i think, purchased last week)
glue is applied with a glue roller

thanks for you advice…. 
i will not over tight, make sure it dries 24hour.


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## Dusty56 (Apr 20, 2008)

This guy claims that the Padauk is an oily wood and states that you should wipe the joints with Acetone before gluing , or use a Polyurethane glue such as Gorilla glue.
http://www.leeswoodprojects.com/species/african_padauk.html

Personally , I haven't had any troubles with gluing up the Paduak , but have noticed some pieces to be oilier than most others.
The Shedua appears to glue well from what I've read today.
Drying times vary with Temperature and Humidity : )


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## sergiozal (Jan 11, 2011)

I use TB III and never had this problem. I apply a thin coat of glue on both sides, clamp and let is sit for 24 hours or more.


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## Tony_S (Dec 16, 2009)

You can squeeze out too much(or all) of the glue if you apply to much pressure and the joint can fail…..

This is something Ive heard…I don't know how many times over the last 22 years as the foreman of a large custom stair and railing shop(and many other types of custom mill work).

(just so you know I'm not blowing smoke)
I'm speculating a bit and trying to go on the conservative side….but Ive seen… more than…. 200,000 bd/ft of hardwood lumber of all descriptions, mostly domestics, but also a myriad of different imports go through the shop over the years.
We go through, on average, about 120 gallons of PVA a month, and many other types of adhesives for various applications.

There must be some weird JU-JU goin on in the shop, because I can honestly say….in those 22 years…I have NEVER ONCE seen a glue joint fail because of over tightening.
And lemme tell ya, Ive seen some real clowns go through the shop in those years. Ive seen guys break the ends of pipe clamps off with wrenches…guys bend and break hand clamps tightening them with a screwdriver in the handle. You name it.
Ive seen guys(mentioned above) with horrid mill work practices, close up huge gaps with large #'s of clamps and enormous amounts of pressure.
It's all good and fine until the clamps come off. Cracks, splits, catastrophic failures. But always the lumber, never the glue joint.
Don't get me wrong, Ive seen glue joints fail….but it's always inadequate, improper, and/or nonexistent surface prep, (or wrong choice of adhesive) of the more oily hardwoods.
Could too much pressure weaken a joint in some way, shape or form? Possibly…but to such a minimal degree it's not even worth mentioning.
*In my experience*, with today's modern adhesives…it's a complete myth.


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## grenger (Mar 8, 2009)

thanks to all for your comments.


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## laanguiano (Jun 15, 2010)

Can you post a picture of some of the cracks. You can tell when looking at the joint cracks if there is glue residue on there or not.

While it is possible to squeeze out alot of the glue, I wouldnt think this would be causing all of your issues as long as you used enough glue… was there glue squeeze out when u clamped it? enough to make small beads or even to drip or run?

My first thought was that the glue was bad, but you said it wasnt bad. Was the glue of regular consistency? or was it chunky or goupy?

Was the wood straight grained, or was it very wavy, or non linear from front to back? or other wood stresses?

How many days was the wood in your shop before you used it?

Did you sand the joints before you glued them? or did anything to them besides cutting them on a jointer or table saw?

Ive never worked with paduk, but i agree on the oily wood could be an issue.

before you started ripping the woods into strips after it was glued up, could you physically break the joints with your hands?? I would think if they came apart when you ripped them that they would have come apart with the slightest tug.

How straight were your joints when you put them together? Did it require clamping strength to get your joints perfectly tight? or were they all perfectly tight without even using clamps?

Is your sawblade perfectly 90 degrees? If there is a slight angle it could mess up with your bonding possibly.

How long did you let the wood stay in the clamps? I suggest 24hrs. It should be fine after 3 IF your joints were perfect, if you had to clamp your joints closed then 24hrs is a minimum.

Also since your in Canadian land, not sure what the temperature is out there, but if its COLD where you have the boards in their clamps, it will take longer for the glue to dry. Maybe 24hrs, and if its real real realy cold where you are clamping the board, the glue may not even work.


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## jasoncarpentry (Feb 18, 2011)

I'm embarrassed to say that I've had the same problem w/ my end-grain boards. Maybe I'm doing my first glue-up incorrectly, but I don't think so. Remember: the smaller the pieces, the shorter the glue line, and the weaker the joint. I often make boards which end up as a series of 3/4" x 3/4" squares.

My advice is to make your second set of cuts very carefully, and HANDLE THEM VERY CAREFULLY until your final glue-up is in place. As I cut each piece on the RAS, I number them and set them on a piece of plywood to give full-length support when I transport them back to the gluing table . Even then, I've had individual pieces break (always at the glue line), so I just re-glue them separately so I don't have to discard any pieces and lose the grain continuity.


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## bannerpond1 (Mar 15, 2013)

grenger, I've made a couple of dozen end grain boards and never once had a glue joint fail.

I would NEVER apply glue to just one face for a joint. Never. I try not to have too much squeeze out, but if you're stingy with the glue, you're asking for a failed joint. The wood is going to soak up a certain amount of glue. If the dry side of your joint doesn't get any glue until it touches the glued face, it's going to soak up some of it. I don't know who gave out that info, putting glue only on one face, but I believe it's absolutely wrong.

Now, for being stingy with the glue, if you clamp those suckers as hard as you can, you're going to squeeze out glue which would have stayed to make a joint. I tighten my clamps until the gaps are closed and I get a little squeeze out. If you never get any squeeze out, I'd say you're not putting on enough glue.

I'm not a pro and I've wasted lots of wood and time, but I've never lost an edge grain cutting board because of a failed glue joint. I use Tite Bond, and I'm sold on it.

I am confident that if you apply glue to both faces and don't overclamp, you will not have such failures.


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## laanguiano (Jun 15, 2010)

Jim,
Even an 1/8" thick piece of wood, edge grain glued shouldnt come apart from the joint. if its done correctly if you try to break the joint, more than likely the wood will rip elsewhere besides the glue joint. many times the glue joint ends up being stronger than the actual wood.

If you have to handle them carefully, then something is already wrong.

Another thing I thought of when reading your comment on 3/4" strips, is that depending on temperature, you need to not be patient with the gluing process. Get it all glued up and clamped in a quick time. Less than 5 minutes preferably.

Also not talking thickness of the wood, but the width of the wood you use on your first glue up (Which is basically a glued panel/table top) the smaller the width the more pieces you will need to get your desired board size. And the more board pieces you use, the more your joints will show error.


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## grenger (Mar 8, 2009)

thnks to all. I will keep in mind all of these good advices;

- adequate time to dry
- Not over-tightening the clamps
- I use TB III
- will check if sawblade perfectly 90 degrees
- clamp 24hrs
etc.etc.

if all fails then I guess i will go for a beer ;-)
thanks again for the good suggestions


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## Straightbowed (Feb 9, 2012)

when you do a glue up then say you cut your strips right then you flip them up for endgrain do you cleanup the squeeze out side before you do the next step I usually run mine back through the tablesaw and take a superfine cut to get rid of all the squeezeout before I do my endgrain glueup


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## stefang (Apr 9, 2009)

I agree with Tony that bad prep rather than too much pressure is the culprit. The thinner the glue the better the bond. That said it isn't necessary squeeze it to death. I think freshly sanded surfaces are most important and there is a lot of controversy on whether or not acetone is necessary for oil woods, which to me means that many folks never use it and get great results anyway.


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## verdesardog (Apr 2, 2011)

According to Fine Woodworking you cannot over tighten a glue joint. I read that in an article several years ago.

All joints that have failed on me have had broken wood not failed glue….


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## NiteWalker (May 7, 2011)

verdesardog, that's my own experience as well. I use a moderate amount of glue, but really crank down those clamps, and have never had a failed glue joint.

I think the OP's issue may have been not enough glue.


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## Straightbowed (Feb 9, 2012)

I really slop the glue on mine very heavy and clamp the crap outta them all I can turn with plenty of clamps no failures yet


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## laanguiano (Jun 15, 2010)

Straightbowed,
Many ways you can accomplish the 2nd task after the 1st glue up. The 2nd is always the critical step where lots of errors can be made. As long as one side is flat and glue squeezeout doesnt affect the flatness, then you could cut the other side on the table saw that way. Works good that way if your pieces werent very thick. But if youre making a 2-3" thick or more cutting board, then its just not a good option (if its over 3" then its not even an option unless you have a 12" Table saw." I also dont do it that way because when you cut them into strips, often times they will spring and curl a little bit. They will be equal in thickness across the strip but slightly bowed from internal wood stress, or from clamping stress. You can manually scrape off the glue with a card scraper, with a blade scraper, with a hand or drum sander. You could use a planer, or even a hand plane. or you can just wipe off the glue with a towel before it dries. That side wont show so it doesnt matter if you wipe the glue off. ive done pretty much all those different options. Each have plus and minus. I pretty much only use my dewalt planer for them all now. Because it gets the board very flat and straight across with the blades. As long as your boards are pretty flat on the planer bed, and you glued them up all in alignment.

Nitewalker
cranking down on the clamps only puts extra stress on the wood, doesnt help the joint if its a properly cut joint that doesnt need force to close. So not sure why you would crank em that much.


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## BoardSMITH (Mar 15, 2012)

Tony_S hit the nail squarely on the head, you can't apply so much pressure to a glue up that you will squeeze all the glue out. Really all you need is 0.003" to 0.001" of glue film. Only gluing one surface is okay and will not weaken the joint. For the past 8+ years I have been making cutting boards professionally and this is how I do it and glue joint failures are almost non-existent.

Spread the glue evenly, get rid of the excess then clamp the joint. I use a cheap 2" natural bristle paint brush to spread and wipe up the excess. If you can't see the wood grain then the glue is to thick. With TiteBond III you have 7 minutes of open time so don't dawdle. If you have gaps before you glue up, you will have gaps after. Clamps will not get rid of gaps and gaps will lead to failures. As you prepare your crosscuts for gluing, do you make sure they are sanded smooth prior to the final gluing. Again, gaps here will lead to gaps later and failures.

When you sand the crosscuts, are you leaving the surface perfectly smooth or do you leave the sandpaper scratches? If you leave some scratches you will increase the glue surface.

Also, when doing the final glue-up, use cawls to spread out the clamp pressure.


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## srzsrz (Apr 15, 2013)

Another way in which applying too much clamping pressure could cause a problem is if you are only clamping from the sides and you don't also have a lot of pressure holding the boards flat. It can definitely be done that way, especially for smaller glue-ups, but if you tighten the clamps too much, things will start to buckle. Even if you carefully jointed the edges so they mate up nicely, this would cause part of (some of) the joints to be loose because the strips meet at an angle. Even worse, if you apply some more clamping pressure after the glue has already partially set, you can cause buckle that will tear apart a glue joint that is not fully strong yet but far enough along that the glue will no longer flow. (How do I know this? It is precisely what happened to a tabletop I was making a while ago. I figured I'd put on a little extra clamping pressure just in case, and one of the joints went "pop." Of course, by that time the glue was nearly dry and taking the clamping pressure back off was not enough to help the situation.)


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## BuckNasty (Nov 21, 2012)

ive over clamped it and didn't let it dry for 24hours…..I learned a great lesson


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## jasoncarpentry (Feb 18, 2011)

After the initial edge glue-up, I ALWAYS run the board thru the planer (both sides) before the second series of cuts. Otherwise, I can't be sure that I'll have straight edges when I do the flip.

I like BoardSmith's idea of rough sanding after planing to increase the gluing area, as long as you remove the dust.


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## DrDirt (Feb 26, 2008)

It is possible to not use enough glue - or to have issues with an oily wood that doesn't bond well.

The overclamping to starve a joint of glue is an old wives tail.

You cannot apply enough pressure with hand tightened clamps to drive the glue out.
For hardwood - Franklin (Titebond) recommends 300Psi. While clamps themselves can reach that pressure, it is not possible to deliver that pressure level to the actual glue line with hand clamps.

as a reference a vacuum bag is only applying 14 PSI.


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## NiteWalker (May 7, 2011)

Adrian A said:
"Nitewalker
cranking down on the clamps only puts extra stress on the wood, doesnt help the joint if its a properly cut joint that doesnt need force to close. So not sure why you would crank em that much."

Things don't always cooperate in the shop. :-{
Most of the time it's for laminations (making a thicker board out of thinner boards).


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## laanguiano (Jun 15, 2010)

Nitewalker:
When you say thicker do ya mean a wider board, or do you mean like plywood, wood on top of each other?

When I make panel laminations, like the first step in a cutting board I now use my jointer. Normally I would take a 7" wide board, and cut it into 2" wide strips, but i ALWAYS got internal wood stresses in the board. so even though I was ripping them perfectly 2" they were always bowed or cupped due to stress. Then I would have to use a little clamping muscle to get the joints closed if I was clamping 4 or more boards together. So now I cut them 2 1/4" thick. Take the strightest side to the jointer and make it perfect, then just do a trim cut to 2" on the table saw. My 8" Jointer changed my woodworking world and precision joints.

Its a great tool in my book… wish i would of had one sooner.


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## NiteWalker (May 7, 2011)

Like plywood, making a 1 1/2" piece from two 3/4" pieces. I crank those down pretty good since I always seem to get hairline openings if I don't sacrifice a goat to the woodworking gods.

A jointer is on my short list.


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## bobasaurus (Sep 6, 2009)

I would say that you need to apply glue to both sides and spread evenly, not just one side as you have been doing. This gives the glue a chance to absorb into all the wood fibers for a bit before the pieces are squeezed together and ensures full coverage. If you spread the first coat too thin and take too long setting up the clamps, you may need to spread more before clamping.


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## laanguiano (Jun 15, 2010)

NiteWalker,
Depending on the length of the wood, it is much tougher to get the faces perfectly milled, almost impossible unless using some planer jigs. Id be clamping the heck out of em too, and making some press clamps.


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## Straightbowed (Feb 9, 2012)

I still is clamping the hell outta mine if they fail I tell my customer it's a free replacemnt, if they follow my instructions on cleaning and reapplying mineral oil once every 2 months or 6 wks but everybody does it different long as we all have fun and enjoy our addiction lets all be happy, seems like you shouldn't have joint failure I use TB 2 never liked TB 3 a little thin for me and Ive had failures with TB 3 on common joints I will never use TB 3 again I personally think it's a weak grade of glue its off color and thin not to my liking I want something that stays on the board and gets tacky in a short time if you play golf keep it in tha short grass


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## skmadden1 (Dec 19, 2018)

If you did not use enough clamps you could have in adequate pressure at certain points on the cutting board.

It might be overkill but I like to use a clamp about every 6 inches. On average I end up using about 4 clamps per cutting board.


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## Phil32 (Aug 31, 2018)

Don't overlook the effect of your own skin oils on the glue bond. Excessive handling of the bare wood, especially the oily species, could affect the penetration of the glue.


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## DrDirt (Feb 26, 2008)

This post is over 5 years ago


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