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I us a 50 50 mix by weight
allow about 30 to 45 min cook time
I do not glue up in a mold I use a 1/8 acrylic flexible caul .
I suspect your clamping process and mixture. I use the brush from tools for working wood. Clamp overnight
should be fine.

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

I know, it looks ridiculous.

My point is mainly to make sure that we are all talking about the same thing. You know, one mans pancake syrup might not truly be another mans thin motor oil.

I do truly appreciate all the help.

FWIW, based on all the replies, I'm on board with too much of the glue escaping the joint during glueup combined with the Irwin clamps. I plan to steam the joint apart tonight and devise a plan to

1) Use gravity to my advantage (Thanks, Don)
2) Apply a thinned amount of glue to both surfaces first, let it dry, then proceed to glue up. (Thanks, Allen)
3) Clamp up by starting first with a clamp in the middle of the block to keep everything together, then add clamps to both sides. (Thanks for the pic, Dave)
4) Use a damp rag instead of dipped q-tips for cleanup. (Thanks, Barry)

It takes a village to educate the idiot.

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How did we get here?
Nothing on this forum seems to bring out more fear and voodoo than hide glue.
If anyone spends time on the olf reading about hide glue, they'll need to take a double dose of Xanax or wind up on the floor in a fetal position upon plugging in the glue pot.

Brad, If you still have a spot that didn't come together or opened up, just console yourself it's an easy fix.
Orient the parts so gravity will carry the glue down in there.
Put your lamp on it while you heat your glue to 150.
Fill up the gap with hot glue and pump it a little bit. This will soften any glue that would hold the joint open and start to release the joint further.
Clamp that b@stard and wipe off the squeeze-out so you can see it's really home. I swear it'll be fine.
Chalk the struggle up to a ripple in the force and keep rolling!

Thanks, Dave. I will give that a try first. As you know, this is the second block I've had an issue with. There is something with my setup that is wrong. I'm going to take everyone's feedback into account and come up with a strategy.

Once it is finished I will be able to sell this guitar for 5x the going rate because of its all hide glue construction.

Aaaaannnndd.... we're off the rails. Appreciate your help!!

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I use a sharp 45 deg angle cut soda straw to clean HHG worms and then follow with a very hot water rag and the sharp pointed straw to clean any residual hhg

I haven't read the whole thread - just the first few posts. Glad you got it solved but I thought I would add my two cents.

My advice is to use the best glues for the situation. I think this clinging to hide glue that exists in our industry is misguided. I use epoxy for gluing things that I don't want water injected in -- thin veneers on the headstock and also the fretboard and also for super oily woods. I use hide glue for all the bracing, plate joining, and bridge. This is where the superior repair qualities of hide glue are useful and may come in handy decades into the life of the guitar. I use Titebond Original for all the remaining parts and I occasionally use CA glue if it makes sense for what I'm doing.

Titebond is very forgiving and is a great glue. IMO, you are misapplying your time here. Get better at building guitars rather than trying to make a specific glue work for you. For what it is worth, I once received a bad batch of hide glue. Every glue joint I tested broke easily. I got a new batch of glue and have not had any trouble since.

Mr. Combs:

Perhaps a shop visit to to a builder that can walk you through the process? To echo Mr. Farmer's comments, none of our first time builders seem to have issues on using hide glue for primary structure (neck and tail blocks, linings, bracing, closing the box, bridge & fretboard, etc.), but that may be because we have the materials, order of operations, and techniques well entrenched in the shop. It may be that spending a few hours on the road to make a shop visit to work through a tutorial with another builder will isolate the cause of your difficulty to adhesive, order of operations, or technique.

I'd be happy to check with the boss to see if we have some open time for a visit if you are within striking distance of the DC/Northern VA area - I hope to be back in the shop in a week or two once the ortho clears me to spend time on concrete (severe sprain still has me in a boot), and it's always a treat to meet other luthiers. Otherwise, perhaps a post here to see who might be available to host in your area (if not close enough to warrant a drive to this neighborhood) might be appropriate.

As Mr. the Cat suggested, becoming fluent in the use of a range of adhesives seems like a worthwhile goal for any luthier. We also had a batch of 315g that came in from a new vendor that had obviously not been stored properly - we returned it after a one ounce sample took almost a day to hydrate!

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This is an excellent offer and if the boss is game I might be as well. I travel a bunch for work and can usually add a day or two before or after a trip. I'll connect with you in PM about that.

Everything I've built up to now is with Titebond. I have had very little or no issues with it. Agreed about learning as many of the glues as possible. However for the next 3 instruments I've already resigned to using HHG throughout. I doubt I will deviate from that path. PVA is a known quantity for me and I have total confidence in using it. HHG is where I'm focused for now.

This is the second time now that I've had a block pull away at the corners when using HHG. Once on a uke and now with this guitar build. It's worth mentioning that I have a cocobolo build sitting next to the guitar in question which survived the bus ride without incident. It's totally possible the EIR guitar is just failed execution and not a problem in the process steps themselves. Hard to know. I'm going to take Mr Farmers advice, shove some glue in there and move on.

I appreciate the feedback. Heal up!

Brad

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Somebody please correct me as I could be wrong about this, since for (more years than I’m willing to admit) I’ve used almost exclusively titebond. My thought is that titebond gap fills much better than hide glue? Not that I’m promoting sloppy poor fitting joints. I’ve always strove for smooth surfaces in glue joints. Thus maximizing glue surface area. Just thinking out loud, throwing this out there.


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such a long thread... i don´t have anything useful to add, but i´d like to say i feel for you. i can agonize about tiny details like these for days, and most of the times i was just too obsessed to see a simple answer right in front of me. I never had the issues you describe with hhg, it´s been pretty much straight forward for me (as long as i don´t let it gel before clamping, but even then it´s easy to reactivate it with some heat) - i much prefer it to titebond, which most of the times seems more like slidebond.
now that i think of it, one thing you could try to do (sorry if this has been suggested, fell out of stamina while reading the thread ) is realise you don´t have to spread the glue into a thin film (like i suppose people do with TB) before clamping. Big blobs of glue hold the heat better, and will get evened out and thinned when you clamp them. At least that was the way i was taught to use it.

and, i agree, don´t get stuck too long on this. lots of others adhesives suitable for that task.

good luck!

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I don't believe either adhesive is particularly good at filling gaps, although there are certainly many good threads both here and on other sites on the characteristics which separate hide glue and thermoplastic glues like Titebond.

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FWIW. I also use a wide range of glues Lately I/ve been using elmers yellow carpenters glue , it was $1 at the dollar store. I was using it to glue a series of heel blocks for a baritone uke, and using the regular titebond as well ,at 65 deg F it seemed that the elmers had a faster to me , tack than the titebond. That is another reason I like fish glue for certain tasks .It seems to have abt a 1min tack which is why I prefer to use it for gluing backs and tops once everything is aligned. I/m also trying out gorilla white PU glue for gluing a 4 piece cocobollo back Takes a few hrs to dry , but with my yard sale hair dryer it can be done in 2 hrs, So Im on the same page as Toonces in terms of using different glues for different parts of the construction process HHG for bracing, Elmers white school glue for putting on my paper logo, etc etc . Your experiences may vary, so test out on scrap your procedure with your intended glue choice before proceeding.

Here's a variation on your clamping approach as a possibility to consider. I do the same as your Step 1. I then use one clamp to hold the block in the correct position, clamping the block to the body mold in the center of the block. I then slide the end of the body mold off the bench so it's overhanging the edge enough to get two clamps on the lower end of the block from below. (This was my solution to the problem of the block "ramping up" from clamping to the caul first as you mentioned.) I then remove the initial clamp and place the caul in position and add two quick clamps to keep the caul where it belongs. Last, I clamp the block to the sides from above using two clamps and the caul. I leave the whole setup overhanging the benchtop edge while the glue sets up. I hope the description and photos make sense.

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Super helpful, Jay. I also like that you simply clamped the caul in position as well. Good stuff.

I do feel like a lot of the glue ran out while the block was ramped up. Of course I would t have that issue with titebond, which is why I would have never seen this before.

Appreciate the feedback and pics!


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In my experience, working through these kinds of problems and solving them is exactly what makes one better at building guitars.

Andy

HI Andy,
Yes and no (just my opinion). The reasons for a failed glue joint are almost always in the preparation of the product or the gluing process. Sometimes you have outliers - like a bad batch of glue but that is unusual.

A highly-skilled luthier that has been building for a decade or two would probably have no trouble at all using hide glue but over the years, I've seen a number of threads discussing problems with HHG. It is my opinion, that builders who are still in that primary learning process should use a more user-friendly glue since HHG is not very forgiving. Personally, I'd rather devote more time to aesthetic/artistic development, tonal development, playability, etc .. I just think that time is better spent. However, I know nothing about the OP's current skill level - so maybe he is doing exactly what he should. In short, my previous comment was more about keeping one's eyes on the big picture of skill development. Over the years, I got sidetracked with things and looking back I feel like that time would have been better spent on developing other skills. Again, I didn't read very much of this thread - so my advice may or may not be relevant for the OP.

I'm the OP and I'm certainly a beginner.

I have built 3 guitars and 3 ukulele's so far. All with Titebond and CA (CA just for bindings, rosette, etc... typical uses)

I set a goal for myself to use HHG for the next 3 guitars and 3 ukuleles. This is partially about trying to learn to build serviceable instruments and partially just my own desire to learn differing techniques. It's understood that building a serviceable instrument doesn't mean HHG absolutely everywhere. Though I may try a HHG purfling glue up just for kicks (I kid, I kid... )

I don't want to make it sound like I'm grinding on this problem for weeks on end. I was / am just perplexed why I've had two neck blocks pull away from the sides when using HHG. At this time I'm really thinking it was an execution error within my own workflow. One that I would have never seen with Titebond. With Titebond when you butter up the block it stays put. Of course with HHG it's all over the place. My process for attaching the block has always been to lightly clamp the block on the "guitar back" end of the block and then flip the mold on its side and then clamp the "soundboard" end of the block. This processes creates the "ramping" I talked about a few posts back. With Titebond this isn't really is an issue. With HHG I was losing a lot of the glue from the joint.

It seems that several folks (Dave F., Jay, maybe others) clamp the first clamp toward the middle of the block which would keep the joint closed during the time I'm flipping the mold to its side.

I really do appreciate all the feedback. I learned a ton from this thread.

Lastly, FWIW, I'm not in any hurry with any of my building activities. I have all the time in the world to try something, see the result, unwind it and try again. I work in software for my day job. You can maybe imagine how entertaining it is for me to do something as simple as gluing up neck and tail blocks. Working with my hands and experimenting with differing setups, jigs, processes, workflows, what ever you want to call it, is a LOT of fun.

Brad

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I certainly see your point of view, and probably in a sliding scale YMMV from one to another. My second guitar was almost completely built with HHG, except linings (that's really a more advanced glue-up for HHG which I suspect you'll agree). I have used Titebond and other white glues plenty. I have no issue with them (all of us know the +/- from one glue to another).

But an end block glue-up is not complicated. Especially on guitar #3 or #4. But there is plenty to learn. How the sides are held, what cauls are used. How one sets up for the clamping. How well is everything fitted (caul to end block to form, if the sides are in a form, et cetera). How does one apply clamp pressure with four clamps, across a surface area, and not have the items being glued "walk" from clamp pressure. I could say more but I think that characterizes the experience one gains through skill. The use of a "rub joint" technique for any emulsion-based glue to create more surface friction before clamping, et cetera. Many ways to skin the cat.

Obviously my point is not about HHG. It will work fine, just like Titebond. But for guitar #3 or #4 this is not too advanced a glue-up for the OP to use HHG. I am encouraging you to figure out the issue and solve it, and let that build your knowledge and experience. If these were linings with HHG, I'd go a different way. But it's an end block - any glue will work, and I mean any glue. I'd like to encourage you to work through the problem for your gain. That's all. Best of luck and let us know how it goes!

Andy

I'll add two points of focus to your process.
1) I'd go finer than 80 grit on your block, but that's just me.
2) I'd suggest adjusting your glue method to a more "basic" process with a glass jar and a bristle brush (as mentioned by John - tools for working wood) in the glue. Bristle brushes work well.

Couple of reasons for point #2 - your plastic bottle is not a good heat conductor, and when you pour from the bottle, the glue cools on contact with the bottle all the way through so your poured temp is probably cooler than if you went straight from the glass bottle with a brush.

Also, from the vid, even though you dab the brush (which cools the brush), it seems as though you're adding a significant enough amount of water that may have an effect. I'm guessing the silicone brush doesn't hold heat well either?

Note: I'm sure using your current methods, there can be success. I'm just suggesting to take out potential variables for defects so you find the root cause of your adhesion issues.

Just my observations.

Are you using a head to tail block spreader? If not, using anything but a circular motion (such as back and forth motion) while driving the bus can cause a lot of chatter on those blocks. Enough to crack the sides.

Hopefully a good glue joint would last longer than the wood. But, if those kinds of stresses were encountered it might be part of the problem.

I also agree with everyone about the Quick Grip clamps. They don't seem to have enough pressure, but the main problem I have with them is that they don't give me any feedback when tightening.

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Pat

I use a 1/2" square dowel that is flexed between the two blocks as a spreader. Just enough to keep the blocks pressed against the mold.

I use the back and forth driving motion. 20 strokes, flip the mold, 20 more, then back again... until my arms fall off. I could stand to take the sides a little closer down to the blocks before starting the bus driving. IIRC they were sticking up about 3/8" above the block on the neck end. Probably a 1/4" above the tail block. I'll watch this more closely next time. Thanks for the tip about the chatter!

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If you create a side profile template (using the body mold, the dish, some posterboard taped inside the mold, a scrap block to compensate for the tapering from neck to tail, and a pencil compass), you can transfer that profile to the sides, and block plane the sides down almost all the way before starting up the bus to fine tune the fit. Saves a lot of physical effort.

Mr. Cumpiano covers a method to get the profile quite close, and a linear motion (back and forth) with rim in the mold and two Bessey Tradesman clamps for weight and handle finishes up quickly. Is there some reason why trying to emulate the motion of a power tool (motorized dish) provides a better result than linear motion?

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Well, I went against Mr Farmers advice (gasp!) and removed the block instead of just squeezing some glue into the gap. I sanded the gluing surfaces up to 220 and wiped with Naptha.

I used the setup recommended by folks here with the exception that I used the 3 1/2” Bessie clamps instead of the 5 1/2” that were linked to earlier.

Clamped the caul in place first:


All the clamps in place:


My poor Irwin clamps are relegated to holding the mold to keep it from flipping over because of all the weight from the Bessie’s.


What a dance to get all the clamps in place! I’ll let it sit until tomorrow and then see the results!

Brad


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Some observations:

1) There was less glue all over the place. Putting the smaller clamp in the middle of the block closed the joint pretty well which kept the glue in place when sliding the mold out over the edge of edge bench. I left the clamp on the center and then put the remaining four on.

2) Clamping the upper caul to the mold helped to bring the block to the caul and not the caul to the block. Pretty obvious, but it made a visible difference in keeping everything squared and aligned during the clamping operation.

We shall see!


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