Another hide glue question

Re: Another hide glue question

joel

>not having done this myself I don't know the answer but I do know that historically cabinetmakers would heat the joints to maximize open time (although the hide glue we have now is better refined than the old stuff and is more consistent ) and reports say they would stick the joint in the stove till just before it burst into flame to get the max open time.

Re: Another hide glue question

John Aniano in Central NJ

>Hi Wiley!

My choice would be to use liquid hide glue. Yes, I know, a lot of folks would say it's the wimpy way out, and that liquid hide glue isn't strong. But hey, dovetails should fit together pretty tightly to begin with, so the long open time is a real boon! I've glued up several dovetailed boxes and drawers with liquid hide glue and have never had a problem and they are still strong and in service.

Just my $0.02 worth,

Take care,

John

Re: Another hide glue question

kees laan

>How is liquid hideglue drying? What's the process? It differs a lot from the liquid fishglue LV offers?

Is it flexible enough to glue post and rung

chairs?

kees

Re: Another hide glue question

Sam Simpson

>Hi Y'all,

Wiley, a dovetail is not a joint that relies on glue for it's strength. I think your fears of dry joints are unfounded. If you really think you need to lengthen the open time, you could thin the glue very slightly. Or, thin it with liquid hide glue a little. But, if you have good fresh glue and have it mixed at the right temperature, there is more than enough open time to put a drawer together.

Now, if you have overheated the glue, or got a froth on top, or reheated it several times over several days, the results are not the same.

When I instruct apprentices in gluing for the first time, I will have them do a small sample of hammered veneering. It is a mess and the results are not much more than sticky firewood. But it gives a very good understanding of the working properties of hide glue.

Regards Sam Simpson.

Be ye not afraid!

Adam Cherubini, NJ

>I would like to use hide glue for dovetail joints. However, I am always fearful of doing so.

My gosh. Are you an engineer too? Just try it. Hide glue is easy to use. Play with it. I put carcasses together with hide glue all the time. I don't heat up anything JOHN (he's an engineer you know).

It probably sets up in a couple minutes, but exactly how long does it take you to put a joint together anyway? So try it with some practice dovetails, and if you feel rushed try this:

1) Make sure the glue is watery, not gloppy. Just add a little more water before you glue (3 hours to 3 minutes before, doesn't matter). In general, you really want the glue runny and watery, it will thicken up when it hits your cold wood. Apply it with an old sash brush. Also, because of its watery nature I avoid applying it to end grain. So that should answer your other question, I apply it to the pins, and sometimes to the mating face of the tails. Don't fiddle with the temperature to change consistency. Once you get that temperature setting correct, leave it there.

2)If hide glue is still too fast for you, you can compromise. Take some of John Aniano's liquid hide glue and squirt it into your glue pot. Liquid hide glue is nothing more than hot hide glue with salt or urea added. Salt or urea makes hide glue:

weaker

slower

softer/more elastic

more prone to releasing with humidity

Now I guess you could buy urea from a pharmacy and add that to your glue pot, but the liquid hide glue has enough of it already so you can use that. This way you can customize your glue to get the properties you need.

For the record:

I've never added anything to my glue (except beer, which Moxon says workmen did- its a really bad idea BTW, but it was ceremonial).

I use hide glue for everything except long edge joints (because of the bondline and speed).

Good luck and get to it. Ther is no substitute for experience ye book learning engineers!

Adam

BSME

BSAeroE

Hey, I resemble that remark ;-)

Dan Donaldson

>I are an engineer too;-) I will have you know that I probably only ate about half of the covers on my textbooks, and I can usually walk and chew gum at the same time. (firmly tongue in cheek)

Good comments. I have been using the liquid hide glue for a year or so now, almost exclusively. The project that I am working on now will be my first use of the hot hide glue, hopefully soon;-)

Re: Be ye not afraid!

Wiley Horne--Glendora CA

>Hi Adam,

Thanks a lot for the excellent detail! Well, I are an engineer of the environmental persuasion, but spent way too much time in planning and the front office to really claim much expertise.

I will try thinning the glue a bit, and if it still outruns me, preheat the wood a little with a heat gun, or else cut the fresh mix with liquid glue. My dovetail joints require some hammering to get them together, but two minutes is plenty.

Much thanks again! Wiley

Doesn't it hurt?

Bill Houghton, Sebastopol, CA

>Don't you kinda bite your tongue when chewing gum with your tongue in your cheek? Or is the engineering solution to remove the teeth on that side of the jaw?

Re: Doesn't it hurt?

Dan Donaldson

>The engineering solution is a sofware controlled automatic gum chewing machine. It has to have at least a dual pentium processor and a 42 horsepower motor. The teeth are titanium for lighter weight, and the speed must be tightly controlled at 1.32567935678 chews per second. It is also necessary to pay close attention to the quality and elasticity of the gum, as well as the amound of moisture that gets added during the chewing process. An artificial tongue and nose monitor the taste of the gum so that you can tell when it is used up. It is a bit expensive to run, but someone has to keep the people that harvest the gum in business so that they can feed their kids, who end up working for the tree plantations and ultimately supply us with the wood that we use to build stuff. See how simple and connected to woodworking it is when you think about it? ;-)

Brilliant return to topic!

Bob Hackett

>You can`t see us,but we`re all doing the Woodworker`s Wave(TM).Our precision timing is bringing tears to the eyes of engineers everywhere.

MB

Re: hide glue

Mitchell

>ok, here's a point that is being forgotten by us in the post gorilla glue generation. hide glue is reversible. if your dovetail joint doesn't set up properly because you have to answer the door in midassembly, then you can undo the joint with moisture and/or heat.

You have to think hide glue to exploit all its potential.

Re: hide glue

Alan Hamilton

>Mitchell,

I think you anticipated my question; and please forgive my ignorance. I know fresh hot hide glue is reversable, but is that also true for liquid, pre-mixed, in a squeeze bottle, hide glue?

Alan

Re: hide glue

Adam Cherubini, NJ

>Alan,

I think I accurately de-bunked liquid hide glue in the wordy conversation above. Might, MIGHT, be worth a read.

But the answer to your question is liquid hide glue is easier to reverse than straight hot glue with no additives. I THINK, the higher gram strength glues (I think gram strength is related to molecular weight- need a chemist here) are harder to reverse than lower. I use the lowest gram weight glue I can get -192, sometimes I can find 135. I think glues are available over 300.

Anyone know what knox gram strength is?

Re: hide glue *LINK*

Dennis

>Always wanted to try this.

Dennis

remove nospam for email


knox glue

Re: hide glue

Don Clark

>If you have any doubt that your hide glue might have partially set up before you got the joint together, just heat the joint a bit. That is an advantage of hide glue, not a disadvantage. You don't have to take it apart.

Also, I have read a lot of statements on hide glue that are just repeats of statements someone has read. For example, the part about liquid hide glue being less strong and less moisture resistant than hot hide glue. I have never seen any tests to back that up. Certainly, old liquid hide glue that has sat on the shelf and in warehouses for a year can be problematical. Since hide glue is stronger than most modern glues, if liquid is less strong, does that make it stronger or weaker than, say Titebond? I don't know, but I suppose it depends on the gram strength and purity. The fact remains that the Turkish Flight bows of the middle ages were put together with hide glue, ( mostly a mixture of liquid hide glue and fish glue) and those joints are probably more highly stressed than any joint you can think of.

Hide glue is sticky and sometimes a pain to work with-gets all over your fingers. It is not very water resistent unless you add some formaldehyde to the joint. It also doesn't fill gaps very well. Otherwise, it is a miracle glue for joining wood to wood and other natuaral materials. (IMHO)

Don Clark

Re: hide glue

Adam Cherubini, NJ

>I'm not sure if your're refering to me when you say folks are simply repeating what others have read or written? (Maybe I got that screwed up.)

But maybe you need me to be more forth coming with my sources.

The guy who sits next to me has a Masters in glue and is one of the top glue guys in my industry. He tells me stuff and answers my questions, but frankly, I don't always understand him. So I may have some of this wrong. I discussed at some length with this fellow the mechanics of bondline thicknesses. I figured that a thick bondline would be always weaker than a thin one, but apparently that's not always the case.

As for additives, I had a long phone conversation with Eugene Thordahl of Bjorn industries. When I got off the phone, I was left with the impression that:

1) hide glue strength is related to molecular weight.

2) All gel suppressants reduce the molecular weight (don't ask me why)

3) salts, urea, KCl, NaCl are common gel suppressents and are all hygroscopic (absorb water) which makes the glue easier to release.

So just to set the record straight, I've only read what Eugene Thordahl sent me, and there was no test data. I recently wrote to Franklin (manufacturer of tite bond) and asked for test data for their glues (they make a liquid hide glue as well). They sent me a packet of stuff. I only skimmed it, but I didn't see what I was looking for.

I talked to my friend here at the office about doing my own test. He told me how to perform a test that would help eliminate some variability (lap shear test), but by the end of the conversation he had me talked out of it.

What emerged in my mind I posted here:

http://www.windsorchairresources.com/chairtalk.html

If you don't feel like hunting for my post, my point was only that gap filling properties are really important when selecting a glue. Hide glue and epoxy can, and pva can't.

Anyway, that's all I know and those are my sources. Its really too bad the guys I work with don't get interviewed on TV shows the way actors do. They are simply fascinating folks. I feel priviledged to work with them.

Adam

Re: hide glue

Alan Hamilton

>Adam,

My apologies.

But in my own defense, you answered my question rather indirectly; and, because of my fading eyesight these days, reading has turned from pure pleasure to something approaching labor. I skim over things until I find something I want to read more carefully.

Alan

test data

Bill Tindall, E. TN

>I may have the test data from Franklin that you are looking for. As I remember it, the white and yellow glues are significantly stronger than hide, particularly in less than perfect mortise joints. I just got off a plane from Hawaii and its been 36 hours since I remember sleeping. I'll dig out reference tomorrow and post, maybe separately.

I think I can explain in understandable terms why molecular weight is important in strength. The statement that NaCl or KCl degrades molecular weight makes no sense chemically. I suspect the effect is on viscosity instead.

PS got to see Matthew D' Avella and he hands down makes the finest furniture I saw on two islands.

Dynamite Bill!

Adam Cherubini

>Dynamite, Bill. You're the best. And you're reading my mind. I asked Franklin for titebond properties in unclamped joints. Loose fitting mortise and tenon is exactly the joint in question.

I'll be thrilled to see whatever you have.

Boy its easy to please an engineer, isn't it?

Adam

Re: hide glue

Don Clark

>Adam,

No, I wasn't picking on your post. In fact I accept everything in your post. As far as test results from glue manufacturers, especially on something as specialized as a loose fitting M&T joint, I would be very suspicious. With any water-based glue, the thickness of the glue (percentage of solids) would have an effect on its ability to fill small gaps. Again, this is an advantage for hide glue since the viscosity can be easily manupulated to whatever you want. Also, sizing works perfectly with hide glue and helps if you are looking for maximum strength in a loose-fitting joint. On the other hand, if you are looking for gap-filling properties, the simple thing is to use a gap-filling glue, i.e. epoxy, thick CA, rescorcinal, etc.

As far as liquid hide glue being less resistant to moisture, I haven't seen any test results, but it is certainly believable. Adding a bit of a dilute mixture of formaldehyde with a touch of borax will eliminate that problem and make hide glue water resistant. I have tried it and it works. It may work too well, however and make the glue joint non-reversible. The simple solution to that is simply to lay down a couple of coats of shellac as a primer or sizer for you ultimate finish. Shellac is very resistant to water vapor transfer and will protect the glue in relatively humid environments. Certainly, I wouldn't use hide glue as my choice for something that might be out in the rain.

Not too long ago, I saw a statement from someone that liquid hide glue joints are not reversible. I checked the reference, and sure enough, an "expert" musical instrument repair site made that statement. The statement is, of course, exactly incorrect. It is reversible, and, as you indicated, maybe more reversible.

I have had occasion to "reverse" a couple of hide glue "joints recently", one using hot glue and one using cold glue. This consisted of removing a couple of sinew backings from bows that I made and didn't like so I removed the sinew in order to re-use it. I simply soaked the glue/sinew mixture in warm water. I didn't notice any difference in the difficulty or time required to remove the backing that was glued with the liquid hide glue vs. the hot hide glue. However, there certainly may have been a measurable difference. Its just that the difference wasn't obvious.

I do tend believe information that comes from Bjorn, because of their long-standing good reputation.

As far as tests for strength, Tim Baker devised a clever method of testing glue strength on wood to wood well-fitted joints which he describes in "The Traditional Bowyers Bible", Vol. I. He didn't test everything, but he did test several. He found that hot hide glue was second to epoxy in strength. Liquid hide glue also did well but was somewhat weaker than hot hide glue. I can't remember if liquid hide glue beat yellow carpenters glue in Tim's test but I do remember that both were strong enough for most any application. Now all the yellow glue manufacturers need to do is test their glue over a period of 3,500 or so years to see if it holds up as well as hide glue.

Don

Re: hide glue positives

Mitchell

>"Hide glue is sticky and sometimes a pain to work with-gets all over your fingers. It is not very water resistent unless you add some formaldehyde to the joint. It also doesn't fill gaps very well. Otherwise, it is a miracle glue for joining wood to wood and other natuaral materials. (IMHO)"

On the contratry Don, hide glue has excellent gap filling properties. It works well on rubbed joints and with impregated burlap to repair upholstery wood damaged with tacking.

I think its weakness, if we can call it that, is an exploitable strength especially when it comes to cross grain gluing as in dovetail and mortise joints. It gives like the sinews it is made from.

there is far too much emphasis on glue strength. the strength of a glue beyond the strength of the wood is simply marketing hype. and as for hide glue, it can be restored with heat and or moisture. It only takes one experience scraping old yellow glue from a failed jiont to make you wish that more people used hide glue.