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I have a few questions in regards to adhesives and deciding which to use and where. From what I've seen and read it appears that most are currently using some type of standard AR wood glue such as Titebond for most of their assembly work. But I know there are many types of this stuff, we keep 3 on hand at the cabinet shop; regular, type II, and regular extend. I have had occasion to use many of the others as well. I know from working with all of these over the years that each possess different qualities not only in workability but also in the finished joint. For instance the type II sets the hardest, the extend takes longer to cure ( not talking about open time) and may tend to gum if sanded too soon especially in humid weather, etc. I also know that the regular AR glues will start to soften and de-bond at relatively low temps, A hair dryer can provide enough heat to do it. I also have used traditional hide glue at times on furniture repairs a few times over the years but never on a continual basis. Then of course there are PVA and others.
So here come the questions. What type of glues do you use and where? Of those using AR types, have you ever had any problems with things coming apart i.e. guitar left in trunk etc.? Aside from inlays, are there any bonds in construction that you feel should be permanent like epoxy or super glue? Has anyone ever tried a urethane adhesive for anything? If anyone out there is using traditional hide glue, I would love to know how you do long complex joints with the stuff like a soundboard to the rims? Seems like it would gel long before I even got it all spread.

Thanks, Brian

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

I admit to be a convert from tite bond original to hot hide or fish glue. Still what is more important is the joint mating integrity. If you have a sloppy joint it ain't no good .

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

With hide glue, for gluing rims a radius dish and go-bar (or other clamping setup, for example two radius dishes and a screw type setup to glue both rims on at the same time) would allow application and clamp up in less than 30 seconds. Do not apply the hide glue with a brush, that would take too long and the glue will dry hard long before you will ever run your paintbrush around the entire rim. Most of my glue troubles have been traced to that.

The problem with the paintbrush application, aside from the fact that it takes too long, is that its rather difficult to apply enough glue to make the joint work properly. For example one of my first failure with hide glue was the fretboard glue job, which was applied with a paintbrush, and I suspect too much time passed before I could get the glue onto the joint and have the pieces clamped on at the same time (since a rubber band clamp was used, this allows the fingerboard to self-align to the neck, eliminating serious alignment issues).

Instead I feel it is better to have the glue placed inside a plastic squeeze bottle, and the bottle would be put in a bath of water that is about 70 degrees C during use. Then the glue will be used like a regular bottle of glue, allowing for quicker application, and eliminating the possibility of brush hairs getting into the glue itself.

However I ended up using Titebond I for future fingerboard gluing. It simplified a lot of things, for example Titebond does not slide around like the slimy hide glue, it grabs the piece and it doesn't move as much during clamping, whereas braces glued with hide glue always moved a few mm due to the go-bar tension.

I always used hide glue with bridge attachments because it would simplify repairs.

I don't like epoxy at all, because it causes allergic reactions, and it is more difficult to remove them for repairs. If the mix was wrong the epoxy will never cure to full strength at all, and it would result in a mess that is difficult to clean up. I only use them as a last resort, for example to glue something that doesn't fit so well (since epoxy fills gaps pretty well) or for previously glued joints that were glued with an unknown glue which had failed (and they have to be reinforced).

I can understand water messing things up for neck constructions, but I pre-tension the neck while gluing the fretboard to make sure that the neck is straight under no tension once the fingerboard is on. That is because the fretboard with frets on it will backbow, and the tension cancels that out. I leave them clamped and tensioned for a longer than normal period to make sure everything is set.

If I could clamp a fretboard in seconds (like that fancy clamping setup Taylor uses), then I would go back to hide glue because that would solve the time issue. It takes too long to wrap rubber bands around the neck.

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
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I think that if I was a guitar builder and thats all I did, i'd use hide/fish glue for traditionality. For me I like titebond II because I build one at a time and I don't work on it all day everyday. I might glue something once a week, or once a month if i'm designing. I don't have to heat things up and so forth. I've built 5 guitars with titebond II exculsively and have had no problems, other than if you have any squeeze out or residue, it can be a bear to sand out. Wipe off any squeeze out if you can after clamping. It can save you alot of elbow grease. When you put the finish on, the glue will show up.

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Jason Moe
LaCrosse WI 54601

hi! i´m very new to all this luthierie things, the only thing i´m doing at the moment is helping a friend of mine building some commissioned work, specially glueing things like bindings, fingerboards,....

for lighter bonds we use hide glue, for stronger / more demanding bonds (like the fretboard to the neck) we use a mixture of hide and bone glue and a "secret ingredient" i´m still to find, but i suspect it being sturgeon´s glue.

cheers,
Miguel.

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member of the guild of professional dilettantes

If the glue surfaces and the hide glue itself are properly prepared, hide glue should be tremendously strong. Certainly strong enough for the fretboard / neck joint, which is about the largest one on the instrument, and not under a lot of stress. Sturgeon glue, or “isinglass” as we call it over here, is the traditional fish glue, quite expensive, what’s secret about it…?

I prefer collagen glues over Tetebond etc. because they so easy to clean up (fish less so than hide), to re-do if need be, to repair, it doesn’t want slide around much when you clamp it, its inexpensive and strong . Plus I can avoid my violin maker friends’ constant scolding… Up here next to the arctic circle guitars seldom get very hot, not even in car trunks in the middle of the summer, so not much reason to chose one glue over the other for that. I haven’t found a local equivalent that is as nice as Titebond or LMI glue though, so I have to order it from abroad, which is an expensive PIA. Depending on the season, it may go bad because it freezes on the way, and it has a limited shelf life, so more and more I just use hot hide or fish glue.

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Rian Gitar og Mandolin

I find hide glue slide around a lot (because it's so slimy) when clamped. What kind of mix were you using?

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

You can stop that sliding by rubbing the parts together a bit before clamping. Once they grab there is no more sliding.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

If it's sliding, maybe you took too much time to clamp the pieces together and the glue had time to gel. I personnaly find that one of the advantages of hide glue is that it stick very well after few seconds... Apply glue and clamp quick, then rub the pieces together. Few strokes, and you can't move them anymore.



Try perforated cauls. Holes small enough to not affect the efficiency of the caul (let's say 3/16''), distanced from 1/2'' each other. It helps for quicker and more even evaporation.

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Francis Richer, Montréal
Les Guitares F&M Guitars

Titebond II will creep under slight stress. Don't use it on guitars unless you need them to be waterproof. Titebond Original is the only one allowed in my shop.

Thanks all for the input. I think I may try hide glue on my first and see how it goes, it is as pointed out the traditional approach. The bottle in a water bath idea seems like it will work a lot better than brushing it on in a lot of applications, thanks for that tip. I plan on doing laminated necks and these are about the only joints I think I will make permanent, Think I'm gonna try some urethane for that due to it's permanence and stability.
Brian

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

I don't like urethanes though... I read somewhere that they work by forming air bubbles to fill any gaps, not good for wood applications.

Besides, hide glue is actually very stable because all instruments older than 200 years old are made with hide glue, and they still hold.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Hi Brian,

I will point you to this thread from December, 2010 which references another thread from back in 2008, there's enough information on those two threads to choke a horse....or whatever hide the glue is made from

Tai Fu, very surpising that you have issues with Hide glue slipping on you. That is one of the benefits of hide glue (as well as fish glue) that they have a very quick initial tack. You can literally just hold the piece in place for 20-30 seconds at the most and it holds in place, I do it all the time when gluing braces.

Also, don't dismiss something from what you've read alone. Personally, I like urethane glue for neck laminating. No moisture to worry about posible warping and that neck will never come apart. Just need the right amount of clamping pressure and a good joint, just like all gluing surfaces should be...

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I could be wrong here but ther may be a chance he had used liquid hide glue. big difference in hot hide glue and Titebonds Liquid Hide Glue. I have use LHG on a couple projets and it takes a while to tack up firm.

My guess with the slippy hide glue is that it needs more water. The directions on mine (bought at Woodcraft, not sure the gram strength) say to use equal weight water and glue, but I prefer it a little thinner so it squeezes out better, especially on large surfaces like gluing on the headplate. Not too thin either though. There's a point where it just feels "right". Also make sure you warm the parts up or the glue will gel on contact and then it won't ever squeeze out. Doesn't have to be hot, just warm. I usually just use my skin as a heater.

For gluing rims, I use individual blocks for the top, and spool clamps for the back (remove a few clamps at a time and squeeze glue into the gap). Individual blocks take a few hours to go all the way around the top. Definitely not "productive", but peaceful and enjoyable work. Short open time is a blessing there

Another technique you could try is the cello style, where you put glue on, don't worry about it gelling up while you get it clamped, and then proceed around the rim removing a few clamps and slipping a heated knife in the gap to re-activate the glue. Ought to be usable with go-bars as well as spool clamps.

I haven't tried gluing a fingerboard with hide glue yet, but I suspect it will be a pain trying to get it clamped in time... might just stick with LMI white glue for that one, since it's still easy to separate if ever needed. I don't do final shaping of the neck and fingerboard until after gluing the fingerboard on, so I doubt any warping from water absorption would cause trouble in my case, unless it was pretty extreme, or of the type that messes up the joint (like a flatsawn fingerboard cupping and separating the joint while wet).

I use hide for stuff like bridges and braces. I have happily used Titebond 1 and LMII.

I think how you use a glue is really important, so to some extent you can't use the other guy's glue. FM's point about drying times is interesting. I was sorta shaking my head when I heard his report, then he mentioned the time factor. I am not moving stuff through, so I don't get stuff out of the clamps all that soon. It would be so easy to take something on board, and then have a discrepancy in some regard and get different results.

The allergic thing on epoxies is way oversold, for most people. I am sensitive, but it is easy to work clean, once you are used to it. I probably would stay away from it if I had to use it every day, unless I was in a situation where I was going to ramp up safety. I think the tough thing about epoxies for some newbies to it, is getting the learning curve at low rates of use. Also, while I haven't tried them, there are eco epoxies made out of soy or something, that while the MSDS is just as horrifying to me, seem to be much less sensitizing.

If you work with urethanes be aware (or verify) that it is extremely carcinogenic in skin contact. So you need to work carefully with it. Makes you wonder how the vapours play with lung tissues. I just see less structural benefits. I do use it in certain narrow boatbuilding applications.

I don't have a lot to add to the Hide glue discussion. If you use a brush, it isn't a dry brushing action you want. It's a fairly heavy coat and then you get a fair amount of excess. I still do it, but making the brush and pot smaller help with neatness and waste, if you want to go that way. Since it is easy to clean in some spaces, it can make sense to overspread it a little to keep some heat in the joint while you need it

With Titebond and LMII, I use the oOerholtzer method a lot. His method is to glue with moderate/light pressure at first, then tighten. I guess one problem with that method is if you use go-bars or vac where you don't have control. The idea is to start with just enough pressure to cause the parts to move together, and then once they have bottomed out bring up to pressure. The only detail here is not to power on the pressure before the glue has thinned since this just causes hydroplaning. Rubbed joints are the same idea. Nothing radically new. But I must say, when I actually did it all purposefully, I found life easier. I love rubbed joints, and do my soundboards that way.

I checked the product inof on Gorilla wood glue. From what I have seen it is a PVA glue like Elmer's white glue. These glues are known to be elastic and creep after curing. As a result, I thought that most people avoid this glue for instrument making. This is different from original Titebond which is an aliphatic resin based glue. If anyone knows that Gorilla Wood glue really is different than Elmr's please let us know.

I like the LMI white for its harness and clearness once dry but it seems to have a shorter open time than Titebond which has sometimes been a problem.

I would love to find a Titebond type glue with similar open time but dries clear. Is Titebond dyed or just "chemically yellow"? Does anyone know of anything like that?

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Chuck Kish

I always thought LMI instrument glue and Gorilla wood glue were the same stuff. they feel the same, look the same , and smell the same. I think the Weldbond glue you can get at Ace is the same stuff too.

-jd

That's what I was thinking. I have a lot of experience with the stuff through my 25 years as a cabinetmaker and when used properly is one of the finest adhesives to be found. The only thing I don't like is the long cure times, but that is the price for strength I guess. To those who have not had good results with it, it is most likely technique. I apply a VERY thin coat of the glue to one surface, VERY lightly dampen the mating surface with a damp towel or sponge and assemble and clamp. The stuff is moisture cured so the little extra moisture really helps with bonding and keeping down the foam that expands out. Clamp pressure and equilibrium is also important as the first stage of curing is a slight expansion, that's where the foam comes from.

Brian

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/