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Hello all, I recently added hot hide glue to the shelf but I haven't used it yet. I'm about to use it tonight to start bracing up 5 soundboards and 5 backs. I seem to remember some folks saying that it cures faster than Titebond etc (one of several reasons I decided to get on board) but I'm still tempted to just leave it for 24 hours to be safe.

The shop is at 55% and about 65 degrees. I can heat the shop up more or turn it down if need be, whatever helps. Not trying to rush the process at all but if I can speed it up a bit that would be great.

Hot Hide Glue dries not cures. I clamp overnight .

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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

I would drop the RH in your shop to at least 45% for bracing tops. FWIW I let braces dry for 3 hours before I take the clamps off. Then make sure not to fuss with it too much, IOW don't carve the braces till the next day... Titebond I let cure for 30 minutes. so HHG is NOT faster then Titebond. For things like bridge patch, head plates, and fretboards let cure overnight. Overnight means 8-12 hours something like that.

Heating up the shop is a great way to have more open time when clamping up pieces together. Many people just use a heat gun to heat the parts before assembling them. Seems to work fine. When I glue sides to the top (open face construction like Cumpiano and Nat) I heat the parts real good, clamp, and then heat again.

I do bridges with 315g strength, clamp 24 hours and string up at 48 hours. Could do less but I like the insurance on the time.

Andy

Raising the temperature will help you with open time but still warm the parts (at least until you get the feel for it); warming the room will also lower the humidity.

HHG doesn’t dry faster that TB but it does grab faster and won’t slip around on you.

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Bryan Bear PMoMC

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For joining plates, bridges, and gluing braces in a radius dish I leave clamped up overnight or a similar amount of time.

Overkill maybe but what’s the rush? There is always other stuff to do.

I don’t stress a bridge for 48 hrs just to be safe.

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It's not what you don't know that hurts you, it's what you do know that's wrong.

The reason the RH is a little higher is because two of them are going to live in VA where the humidity is typically 50-70% (at least for me) in the winter and 70%+ in the summer, kinda backward from Alaska. I'm just a little paranoid about the top swelling up. The last guitar I built in Alaska came to VA with me and required a lot of work after the top swelled with humidity. I built that guitar at about 40-45% RH so that's why I'm a little paranoid.

Thanks for all the advice and responses. I'll clamp a couple up tonight and leave them overnight and get the next pair tomorrow morning.

That makes good sense. Here in the mountains of VA it's not that bad but down in the Richmond area... OMG I could never live in that heat and humidity

Haha, yeah tell me about it. The funny part is that I don't really live near any type of civilization. Richmond is 1:15 drive and Lynchburg is about 45 minutes. It's always nice to get up to the mountains where it's cooler but this whole friggin state is too hot and humid for me! Some place like Montana might eventually be the compromise if I stay in the lower 48.

I'm in East Tennessee, similar humidity, and we spend quite a bit of time with the outlaw in-laws who reside on Gwynns Island Virginia in the Chesapeake bay. I brace at 45% or lower and have had no issues with weeks at the beach. One hour and HHG is good to unclamp, bridges, wait 12 hours before stringing, good luck

A few years ago I did one of those experimental guitars (nylon classical) in which the bracing is glued to the outside of the soundboard. Bracing went on and then I glued the bridge (HHG) just held with finger pressure alone for a few minutes. 5 hours later the strings were up to full tension. Both bridge and bracing was still on some 3 weeks later before I dismantled the whole guitar. I'm not suggesting that you make this your practice but it sure tells you something about both it's holding ability and that long clamping times just aren't necessary.

I hear ya. I'm a Connecticut Yankee living in the South. This is about as hot as I can take it. We at least get a bit of snow in the mountains and of course this winter has been pretty darn cold. The repair business had a spike due to the dryness.

One thing about hot hide glue: it can surprise you how fast it dries out. I’m not talking about the joints themselves (although this is useful information for understanding the joints). I’m talking about the squeezeout. At first, after cooling, it is gelatin (literally). You think, OK, it will be like that for a while. But that gelatin loses its water faster than you think. I just offer that as an observation.

Overnight is my standard wait time for cutting or sanding a joint put together with hot hide glue, but I have glued in the morning and cut in the evening without a big problem, if it feels dry. Certainly, I have never had a hot hide glue joint sit overnight and not be fully dry by the morning.

A lot of how you use HHG depends on 1, product gram strength , 250 , 315 etc 192, higher g strength less set up time. One can add urea or salt as a depressant to higher g strength of HHG , but it can lose some of its strength in the process.How warm or hot is your work space . Martin gibson etc probably used a warm room 80 deg fh for initial glue up to keep the hhg more liquid I use a recycled hair dryer in winter. On bracing , I remove clamps after 1 hr. on bridge glue ups using 315 g I wait at least 24 hrs.I just don/t like bridges flying past me. I also prefer fish glue for some tasks gluing top and backs, sometimes bracing headstock etc. I like the fast tack. Experiment on scrap . till you get the results you want !!

I'd recommend anyone who works with hide glue to try this:

Take a piece of spruce the size of a finger brace, and a 2x4 or something. Sand them both good and flat so it doesn't take any pressure to close the joint. Slop some hide glue on the brace, stick it down, and hold it with your fingers for a minute. Let go and leave it alone for 10 minutes, and then try to pull it off

All I can say is....I don't know what took me so long. I had a bad experience with fish glue early on (bindings) and kind of shied away from hide glue until now. Boy was I silly! Quick tack, super easy clean up and I even made a mistake gluing a lining in the wrong place that I fixed in under 2 minutes.

Late to the party by about 7 years, but glad I finally came!

Out of curiosity is there any task that you guys avoid using hide glue for? The quick tack and reversibility has me wanting to use it for head and tail blocks as well as the cutaway portion of my Florentine cutaways since it's so easy to fix I get something wrong vs having to route off an re-do.

I don't use HHG for bindings or gluing on the back because my process in doing so requires too much time. I use Titebond for bindings and Fish Glue for backs. But honestly I don't find Titebond to be difficult where reversibility is concerned. HHG still has it's advantages but it's not too difficult to remove a bridge or reset a neck glued with Titebond.

I had some struggles recently with neck / tail blocks and moving to hide glue. Just make sure you have your glue up procedure dialed in. I was used to using titebond and had all kinds of issues with getting a good glue up with hide glue. The corners of the sides kept peeling back a little. So I took a stpe back, remade the jig I use to put the radius on the blocks so that I was 100% confident in the fit, then went over and over the procedure with the help of the folks here and got it sussed out.

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For the time consuming things like box closing, don't worry about it gelling up. Just reheat after you get all the clamps on.

I use it for bindings too, but may switch to Titebond there just for efficiency. With hide, I can usually only get one strip done before it starts to dry out, so some time is wasted heating it repeatedly. And heating loosens the tapes so then I have to pull those back down too.

I like fish or white glue for kerfing, fish for binding, and fish for putting on tops an backs , HHG for bracing titebond for blocks , fish or epoxy for FB

I was considering fish glue for blocks. Any particular reason you add titebond to your glue choices just for the blocks?


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The only place where I don’t use hhg is when gluing veneer stacks, or gluing veneers to bindings or headplates. For back and top joining, bridge gluing or closing the box I leave overnight. For fingerboards, I try to leave it for a week. Mostly to make sure the added water finds its way out. For stuff like brace gluing, around 90 minuets. Mostly because I’m eager to carve them and it seems to work. Dentellones, around 10 seconds of finger pressure.
Like Dennis, I often let it gel and reactivate it with heat when the clamps are in place. Works ok.
If you cook some glue tests, you’ll be amazed with the tenacity of unclamped hhg joints.

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Right now, I am using hot hide glue for literally everything that stays on the guitar. No Titebond, superglue or epoxy anywhere on the finished product. With the addition of urea for some operations, and varying the thickness of the glue here and there, I can do it and it actually works out great. It’s important to me that I just cook a small amount at a time (3 ounces or less). That lets me vary the composition of the glue to fit the task.

I don’t do this for a living, so I can afford to just do what I want at my own pace.