Official Luthiers Forum!

This week I've been repairing the guitar I built around 8 years ago for my best friend and musical partner. She's had to keep it in her garden music shed because of extensive house modernisation, and the winter has been unkind. I've fixed four popped braces, two open seams and a back crack.

Almost all the major construction was using HHG, and I was so pleased when it came to repair time. Braces and seams were just a matter of brushing in some HHG and clamping, with no need to remove all the original glue. Working blind inside the guitar was challenging, but I didn't have to worry about open time. Once the braces were clamped in place I could just gently heat that part of the body to reactivate the glue then snug up the clamps. An experienced repairer wouldn't have struggled like me, but I'm an amateur - maybe I do 2 or 3 repairs a year, so I'm almost starting from scratch each time.

I'd guess other amateurs might face this kind of repair problem from time to time. Most of us can't sell our instruments (at least, for a reasonable return on materials and time) and so many become gifts. If my gift needs fixing, I guess it's down to me to do that.

Why did I build with HHG in the first place? The conventional wisdom seems to be that it's too difficult for beginner builders, and should be left for later (if at all). I don't think that's right.

I started my first build using HHG. I didn't know any better - it's a traditional instrument glue, I was working entirely with hand tools, so why not go traditional?

Here's what I found:

1. It's messy to start with until you learn how much glue to use, but at least the cleanup is easy. And HHG washes out of clothes!

2. Mistakes are fixable! So you glued the bridge in the wrong place - just heat it up and pull it away, clean up with water and start again.

3. Tricky glue ups can be done in stages. To glue a back on for example, just apply the glue all round and clamp at head and tail block. Then work round the body, heating and clamping as you go.

4. You get a second go at most visible glue lines - heat, add moisture, clamp again.

5. The equipment's not complicated - a second-hand baby bottle warmer, a plastic pot, some cheap artists brushes and a hair dryer are all you need.

6. A rubbed joint can be really helpful for some things, and HHG does this better than Titebond.

7. Later repairs are easier.

None of this is a plea for everyone to use HHG. I also have Titebond and CA, and I use those when I think they'll be easier or better.

But I don't think anyone should be put off HHG because of some myth that it's only suitable for experienced builders. My first instrument (a uke) fell apart because I chose pretty wood, but also unsuitable wood (crotch cut yew for the top, humidity and internal stresses killed that after a few years), not because of HHG - the joints are still intact after 15 years.

Thanks for the shout-out for HHG! It is a bit intimidating for the newbie, but as you mentioned, you don't need a (WHAT!! I was gonna say fancy $100 glue pot, but they are $250 now!!) fancy $$ glue pot, and electric warming blankets to use HHG. Like you said, a baby bottle warmer, and a hair dryer will suffice for most Luth applications. As far as rubbed glue joints? I won't use anything but HHG!

There’s certainly a lot to be said in favour of HHG…

Hot hide glue is the only adhesive I use when building an instrument. I use plenty of Titebond, CA glue and epoxy for other things, but as an adhesive for wood-wood joints on a musical instrument, hot hide glue is top of the heap for me. And that is without regard to tone issues.

But, for someone building a first or second instrument, there is a lot to deal with, and learning how to manage hot hide glue is probably something that can (and maybe should) wait until a later instrument.

Having said that, I led a class last fall for beginners on building ukuleles, and I made them use hot hide glue. They all did great with it. But I was there to help.

When I first started back in 1972, the instructor recommended Lepage's yellow carpenters glue. When i found HHG, it was a revelation. I was using HHG and Lee Valley 2002 for a while. I came across an 'Acoustic Glue' that was only sold to 'professionals', and was discussed in a thread a while back. It dries glass hard and it's high solids/low water. It can release with heat, but not re-bonding like HHG. I use HHG for most things and the Acoustic Glue for trickier glue-ups.

I've heard of this mysterious Luthiers White Glue from back in the day - is it still being sold??

Thanks!

I find this useful for HHG, cheap (I paid <$40) - The double boiler gives me an extra bath for clean-up, etc.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I was just looking at one of those online, Colin. I currently use laboratory hot plates and MusiCaravan double boiler type glue pots. Do the burners hold their temperature well? and do the burners heat from the bottom, or all around?

I've been using this for several years, holds the bath temperature well, but the set point for temperatures vary with exposed water and glue surface areas.
I use a circle of aluminium on top of the pots with holes cut out for spice jars to hold the glue normally (brush), or just a jam jar for making up glue, or for say applying side reinforcement ribbons.
I think the heating element is attached to the bottom of the pots, individually., I use cut out circles of stainless mesh under any glue containers. to keep them off the bottom, just in case.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I’ve got the old Hold-Heet pot. It’s performed flawlessly for 20 years. Not sure if you can get them anymore. Glue mixed in plastic squeeze bottles.

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

Mini crock pot for me…holds at 140 perfectly…

Your points are well made and I don't think they get said often enough. HHG can be intimating for a beginner but that is really silly if you think about it. If one is setting out to make a stringed instrument and is comfortable learning all the skills involved in that, then learning the quirks of a type of glue should not be a deal breaker. that's like setting out to become a marathoner but insisting on velcro running shoes because knots are hard. I think sometimes the advice and tips for using HHG come off as unintentionally intimidating and it scares people off. When I first started using it, I was amazed at how much less scary it was than I thought.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

If we are going to aim this at beginners then I will add my $.02 that a mix ratio that works for me is 1 glue to 1.6 water by weight for 192 gram glue. I think this was first shared by Don Parker, or at least that’s the first time it registered for me.

Nothing made me crazier when I started using hide glue than to be told to make it like “thinned motor oil” or “warm syrup”. Those descriptions mean nothing.


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Mmmmm--warm syrup . . . I wish we had a Homer Simpson emoji.

Yeah, some of the advice is inexact, but since it is a ratio you can play around with and nothing really bad happens when you do, it's not as harmful as being inexact about epoxy ratios, for instance.

The reason I use the ratio that Brad mentioned is because I like the glue a bit thicker for most things. If it is too runny, it tends to be harder to manage. At least, that's true for me. A standard bit of advice you sometimes hear is 2 parts water to one part glue, by volume. That winds up being pretty runny for my purposes. But, to each their own.

Special tasks can call for a runnier version of glue (i.e., wicking into a crack), in which case, add some more water and have at it.