Loose tenon glue up, Epoxy or Titebond?

Where are the data to support the claims

Bill Tindall, E.Tn.

"They do not permit glue-on-glue applications" I have thought about this claim since I first encountered it. Lacking data I have not reached a conclusion about their validity. There is no obvious adhesive theory to support them, but molecular details could make them true.

I see two cases. New assembly where a mistake was made and we want to take it apart. Old joint where the glue has failed or the wood has failed and a sound joint needs to be disassembled to replace the wood.

First point: I have repaired hot hide glue joints where the glue was brittle and crumbly. When a hide joint fails because the glue has failed would it not be prudent to remove the failed glue?

Second point: Given that essentially no one uses hot hide glue the claim becomes that liquid hide will stick to cured liquid hide and cured hot hide. And the corollary, aliphatic glue won't stick to itself. While the claims may be true, I have an open mind about it, there is no general adhesive science theory that would predict cured aliphatic glue won't stick to itself or that liquid hide will re-stick in repair. What happens depends on molecular details that would need to be tested to reach a reliable conclusion. I have wanted to test this claim about aliphatic glue but have failed to come up with an experiment I have confidence in.

It is common practice to size miter joints with Titebond before gluing them. This practice suggests that the aliphatic resin glues do stick to themselves. But I keep an open mind about the claims but don't repeat claims where I lack data to confirm them.

Yes....

Barry Irby

Dominos have tiny ridges on the rounded edges that allow excess glue to escape and the machine cuts the mortises a couple of mm too deep to provide a well for excess glue. On the narrow setting the fit is snug in both directions, but the ridges provide tiny V grooves (really tiny) to the glue to escape. Very well thought out.

We have success....

Barry Irby

I have successfully glued up all four end panels.

This was not a particularly difficult glue up. Two styles and two rails with two dominos in each joint. And a asymmetrical panel to get fitted. I was nervous because I had many hours in prepping the parts and no spares. and it was my first glue up with dominos.

I have assembles dozens of traditional M and T joints I cut by hand and with a hollow chisel mortiser. Some were tighter than others and I was never sure the fit was good enough so I used epoxy. Excellent epoxy, not the cheap stuff. They all worked well.

So when it came time to do the dominos, I chickened out and used the same epoxy. Shame on me. I was afraid the Titebond glue would swell the dominos, making an already snug fit nearly impossible. After doing the first frame I knew the dominos worked perfectly and should have switched to Titebond, but I talked myself into going with consistency and used epoxy on them all. Could not have gone better. Even when I stopped and made minor adjustments to one of the panels.

Bill is right abut the Titebond seizing. Hammering it does little more than beat the project to death. I have used clamp pressure to move some long tapered dovetails when they would not move. They move like butter under gentle pressure from a clamp.

In the future, its Titebond on the dominoes.

A valid reason to consider Liquid Hide

Bill Tindall, E.Tn.

Shown is the side of a chest of drawers that will be assembled with dovetailed drawer dividers. Normally I overlay a thin face strip to cover this joint. But in this case I may leave the dovetails exposed. If I do exposed dividers, the joint must be perfectly in registration to look good. In this case I would glue in the dividers with liquid hide. Why......

When Titebond is used on a sliddy joint (dovetail or mortise and tenon) a properly fitted joint will slide together until the sliding stops. Sliding my not easily restart for fine adjustment and a clamp may be necessary to coax a joint into perfect alignment. In the case of this chest of drawers there will be 20 dovetail joints to align. You can see the problem.

Liquid hide acts like grease on a slidy joint. A dry joint that resists pushing together with hand pressure may easily push together after glue is applied. Liquid hide glue will make aligning the dividers with the case sides much easier than the case with Titebond.

Re: Where are the data to support the claims

Derek Cohen (in Perth, Australia)

No technical data, Bill, but certainly so in my experience.

I use Titebond Liquid Hide Glue, not hot glue. I do not repair furniture, and so I cannot speak to the brittleness of age old hot glue. There have been times when I have had to pull joints apart and re-attach the parts of recently built pieces. Re-gluing joints has never been an issue with LHG. On the other hand, I have not had success with the other TB glues in this way.

Is the reputation fiction?

Regards from Perth

Derek

My experience too.

I agree, and a question for Bill,

Barry Irby

and anybody else who makes chests of drawers.

What do you consider the "perfect" proportions and dimensions?

I am making a pair, one for each granddaughter, and they have turned out to be 43 1/2 tall. I sequenced the drawers, 8,7,6,5 and a pair of 4's at the top. With the spacers between the drawers and the top and bottom spaces it came up to about 43" The width can be adjusted. Would 30 or 31" be good? I am about to create those slidy pieces Bill showed and now is the time for the decision.

There are at least two more Chests coming behind these two so of all the chests you have made and seen what height and width struck you as best?

(My engineering brain is twitching. I am about to buy Baltic Birch plywood to use for drawer bottoms and it comes in 5' square sheets. 30" drawer bottoms are looking mighty attractive.)

Testing is boggling complicated to consider

Bill Tindall, E.Tn.

"Is the reputation fiction? " I don't know, and the chemist I knew at Franklin was unaware of any data.

The following discussion is for Titebond original and typical white. The polymer chemistry involved in the versions of Titebond that crosslink could easily lead to a cured glue surface that would resist bonding to fresh glue. Titebond II and III have little place in furniture assembly.

The experiment is not trivial to design. If the joint was taken apart with steam, a common technique, the aliphatic resin glue has been replasticized by the water and I see no reason this material would not coalesce with new glue. But how would one test this situation.

I have never seen a failed Titebond joint. Not knowing what one would look like it is hard to imagine an experiment test reglue. The only route I see to failure of a Titebond M&T or dovetail is poor machining leading to the glue gap filling, which in turn is guaranteed to fail if simply reglued, by the same mechanism that failed the joint in the first place.

We know that sizing the miter with glue is common for miter assembly. This fact suggests new glue sticks to cured glue, or at least glue that has not cured for decades.

You reported. "On the other hand, I have not had success with the other TB glues in this way. " Will you provide more details, off -line if you prefer, for me to consider. If the glue was not Original or white, end of story, experience not relevant to my interest in topic. What was the joint, how was it taken apart, how was it reglued and then tested? What was the measure of lack of success?

Why is this discussion important? Because Duffield claimed anyone making furniture to last should be using hide glue because it can be repaired and Titebond regular can not. I regard this claim false. Aliphatic resin glue has some clear advantages over hide of any sort for furniture assembly. There are reasons that a local furniture factory, and most others, purchased it in 55 gal drums, rather than hide. Hobby woodworkers should not be abandoning it for reasons that are not supported by data.

comments

Bill Tindall, E.Tn.

Things to consider.

A drawer wider than 3' becomes difficult to fit well and use.

The case height is determined by how many drawers are needed.

A drawer taller than about 8" becomes hard to make and fit and use.

Common drawer spacing is to have each drawer larger than the one above by the divider thickness.

At 6 drawers high a solid wood chest of drawers is near impossible to lift by two people. 5 high is manageable. 4 makes a shorter chest which could be desirable depending on what is to be set on it.

for children something about 26" wide seems about right for them to manage

I often fill out the top of the chest with two half drawers the same height as the full drawer below. On a wider chest it might be a full drawer, then two half drawers one divider less tall then 3 1/3 drawers the same height as the half drawers below. I think these patterns look nice and the smaller drawers become functionally useful. Look at my gallery for examples.

I never use plywood for drawer bottoms. Bottoms are such a handy place to be rid of less than perfect wood. I resaw wood not pretty enough to be seen in front and glue up bottoms to finish at 3/8"....... strong enough to hold all but the lead brick collection. People tend to make drawers from lumber unnecessarily thick. I use 7/16" sides and 3/8" bottoms. Makes for a light weight easy to use drawer.

Re: comments

Barry Irby

Thanks Bill, I appreciate the time it took you to write that up.

You are correct about 8" drawers. Any more than that the seasonal change in dimension becomes difficult to manage.

Since these chests are for girls, I am considering two or three very shallow drawers at the top that could be for jewelry.

I realize I asked a "How high is Up?" question But I guess what I was fishing for was perhaps you had made one that was an Ah Haa! moment for you.

How High?

Mark Mandell - Gone Round In New Jersey

Depends on what you're smokin', man.

[Couldn't resist]

check the Gallery

Bill Tindall, E.Tn.

I have two chests of drawers posted in the Gallery made for granddaughters- one cherry and one with a figured walnut front. If you like them I will provide dimensions. They have proven serviceable.

Re: Testing is boggling complicated to consider

William Duffield

https://en.wikipedia.org/wiki/Wood_glue

A few other things to consider:

PVA was discovered just over 100 years ago, and began to be used for building furniture some time after that. So there are now some pieces that could officially be called "antiques" that used yellow glue in their original manufacture. Hide glue, and other collagen-based glues, have been used successfully for centuries. So, even the highly skilled and very experienced Headley shop has very little experience with the long term breakdown of aliphatic resin glues in antique furniture. I have heard rumors to the effect it starts to occur at around 75 years. Perhaps only coincidentally, that is about how long the four generation Headley shop has been in operation. I wonder if they ever used hide glue in their reproduction furniture?

http://www.headleyandsons.com

"The only difference between our furniture and the 18th Century pieces is 200 years."

Maybe it's all "old wives' tales" but I have been told many times by many experts that you need to completely remove all the old yellow glue (and most other types of glue, including epoxy) from a joint before attempting to reglue it. This is not necessary for hide glue.

Yes, hide glue eventually gets brittle and the joints glued with it fail, and have to be reglued. I understand that the brittleness is mostly due to loss of water from the glue, exacerbated by modern central heating systems. However, there are opinions that it can also be caused by very high humidity and temperature conditions.

One more cautionary note: it is very inadvisable to use steam to disassemble joints made with animal protein glue, because the proteins start to irreversibly break down at about 156°F. IF the temperature gets any higher than the water in your gluepot, you are committed to completely removing the hide glue before regluing and reassembling.

Re: Wow! thanks for all the responses.....

William Duffield

I think the main reason the tenons are difficult to remove is because Barry and I live at low elevations in the MidAtlantic region where the humidity is high. Around here, we call it "Tidewater." Therefore, the tenons swell just enough to make them difficult to put in and take out. Festool has tight tolerances on all their systems, and the Dominos are made in Hungary, IIRC. I don't know whether Barry's shop is air conditioned or centrally heated in the winter, but mine is not. You shouldn't have as much problem at 6000 ft. or better in the foothills of the Rockies.

If I am having fit problems, I easily correct them by laying each domino down on a sheet of sand paper and rubbing it back and forth a few strokes on each side. It takes about ten seconds per tenon. Sometimes I also remove one central glue relief rib from the curved surfaces by the same method.

Re: Wow! thanks for all the responses.....

jesse cloud

Humidity may not be the main cause. I live at 5,500 ft in the New Mexico high desert area. Except for the "monsoon" season (an hyperbole if ever there was one), humidity is in the 2 per cent to 5 per cent range. Dominoes are still awkward to remove sometimes.

I, too, often remove or trim the central rib to get a better fit.

BTW, did you read where Bill T thinks 'essentially no one uses hot hide glue'? I sure do - don't trust that liquid stuff one bit.

Re: Testing is boggling complicated to consider

Derek Cohen (in Perth, Australia)

You reported. "On the other hand, I have not had success with the other TB glues in this way. " Will you provide more details, off -line if you prefer, for me to consider. If the glue was not Original or white, end of story, experience not relevant to my interest in topic. What was the joint, how was it taken apart, how was it reglued and then tested? What was the measure of lack of success?

Bill, here is an example that comes to mind ..

There have been occasions when, using TB1, I have not waited long enough for the glue to dry and begun planing down a joint (it could be a M&T). The joint moves slightly, and now it needs to be refitted. Pulling the joint apart, the glue dries. Adding more glue does not work. Only scraping out all the old glue and re-gluing is successful. I have not had this problem with LHG.

Regards from Perth

Derek

Re: A "somewhat scienctific" functional test

Larry Clinton At Frankfort, (Central) Indiana

was on the internet a few years ago. It used force gauges and /or consistent weight blows to determine "holding power" of various identical joints in wood of various epoxies, Hot hide glue, commercial liquid hide glue and polyurethane based glues to determine strength of re-glued joints. This was conducted with joints first glued with one adhesive then broken open using the applicable heat, steam, force etc. needed to disassemble the joint and then re-glued with the same adhesive and / or other various adhesives. It did demonstrate that NONE of the polys or epoxies were near as strong when re-glued as the Hide glues.

I have always hated to repair chairs and other furniture that had loose joints that had been glued with a "modern glue" or epoxy. Therefore all my repairs are / were made with hot hide glue. I have had to oversize the mortise's and remove some of the tenons to remove all the old adhesive. Then I build up the tenon using plane shavings or veneer and hide glue to refit the joint. It has been very successful so far, and does make it very easy to repair later (almost all kitchen chairs will need repair a few times during their working lives).

I use a heat gun and clamps / mallet to remove joints with poly or hide glue. Most epoxies must be removed with force only as heat, steam or solvents will not soften the epoxy. As an aside when I worked as an Engineer, I did have a solvent that would remove cured epoxy, however it also damaged or destroyed most substrates! During my career I worked with many epoxies, cyanoacrylate's, and contact adhesives. These were used in our products and purchased in bulk, usually 5 gal buckets.

Don't you think...

John in NM

That maybe reputation for hide glue vs. other adhesives comes from it being reversible, the others are not. It's surface dissolves slightly with moisture and perhaps heat from the new glue, and the new glue is better able to bond to it.

All the tightbonds & epoxies don't do that, and are in fact specifically designed to not do that. Small wonder they won't stick to themselves!

I used one version of white glue once that was reversible. I've forgotten the name of it now, but it was essentially a high grade school glue, and had wonderfully high initial tack. We used it to glue radio absorbing foam into a cone for making a calibration cold load that would be dunked into liquid nitrogen and held in front of the receiver's input path. I was very surprised it would stand up to that kind of thermal cycling.

That is exactly why I like hide glues...

John in NM

Though I prefer hot myself. It's wonderful stuff!

Re: The important feature is re-use

Brian Holcombe

Bill I use liquid hide and titebond III depending on the goal of my glue up. One furniture maker advised me very early on that I should make everything repairable. I have followed that where practical and it makes good sense to me. If liquid hide is more easily repaired and potentially longer lasting, then I use it for joinery. On the other hand, if I'm gluing a panel I see little downside to using titebond iii.

The downside to LHG is that is takes long to cure, I'm used to clamping things for an hour and LHG needs overnight clamping.

Re: The important feature is re-use

Derek Cohen (in Perth, Australia)

I use TB Liquid Hide Glue for almost all joinery these days. The one exception recently was the kitchen door frames and panels I glued up using TB III, as it is water resistant. My concern was that steam or heat in the kitchen might affect hide glue. Joinery was with Dominos, incidentally.

Regards from Perth

Derek

Dissolving not esssential for adhesion

Bill Tindall, E.Tn.

When two pieces of steel are bonded with cyanoacrylate or epoxy obviously the steel doesn't have to dissolve to make a bond. On the other hand, if a layer of polymer(glue) is applied to another, and the polymer molecules ( cured glue) at the interface become mobile enough to entangle (what will happened if the applied layer dissolves the surface of the substrate layer) the interface will disappear. The resulting material will have no discernible interface between new and old. New will be bonded to old.

I don't know if aliphatic resin glue will bond to itself by pure adhesion as in the case of gluing two steel plates together, or in this case of new glue sticking to cured by simple adhesion as epoxy sticks to steel.

On the other hand it should be possible to plasticize the molecules in a cured aliphatic glue surface enough to bond a new glue surface to a cured one. The question becomes whether typical gluing conditions are sufficient mobilize the molecules in the cured glue surface. Perhaps a better solvent for the aliphatic resin than water would be required.

Where is this data?

Bill Tindall, E.Tn.

I would like to study it.

True enough...

John in NM

But it is probably one of the more common mechanisms for plastic (as in property rather than substance) materials like PVA glues. I would bet that if there were a suitable solvent that could be applied pre-application, adhesion of PVA to dry PVA could be improved.

The other thing that strikes me in these conversations is that there is a large degree of selection bias in the anecdotal evidence. The vast majority of regluing required is the result of a failed joint, and most joints fail through being poorly made rather than through glue choice. Reglue the joint with new PVA over the old, then the glue gets blamed for subsequent joint failure, when in fact it is likely the joint more than the glue!

Re: True enough...

Bill Tindall, E.Tn.

"I would bet that if there were a suitable solvent that could be applied pre-application, adhesion of PVA to dry PVA could be improved. "

You are correct. Whether water will replasticize the surface is unknown to me. Warm water certainly will or it would not be possible to take apart a Titebond joint with steam, which condenses to warm water in the joint. I am trying to devise a test to see if newly applied glue will adhere to cured glue surface.

" Reglue the joint with new PVA over the old, then the glue gets blamed for subsequent joint failure, when in fact it is likely the joint more than the glue"

This is the issue I am struggling to understand. A well made joint has microns of cured glue between the mating surfaces. Anywhere glue has gathered to make a deposit large enough to see and scrape will be "glue foam" and glue foam has no strength. Titebond is about 50% solids so when a blob dries the dried material is 50% air(foam). It would seem by definition that anytime someone talks about removing old glue that the joint was made with gaps. There is no way to remove the glue soaked into the wood without removing wood and expanding the joint. If wood soaked with cured glue won't bond to new glue I would conclude that a Titebond joint can't be effectively reglued. I am testing this property.