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Since my next task is to install inlays and I've been asking about HHG, does anyone use it for setting inlays. I've used epoxy in the past.

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Hutch

Get the heck off the couch and go build a guitar!!!!

Nope, I started out using epoxy but have used CA for the last 7 or 8 years. I use the black CA on ebony otherwise the clear. For lighter woods, if I have a gap I just put wood dust in it. I have collected a lot of different kinds of wood dust from sanding so I'll try to find a slightly lighter colored dust for the fill since the CA will make it darker. I'm very careful when I cut the recess for the inlay and try hard to avoid gaps.

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Steve Smith
"Music is what feelings sound like"

Here is what I do: I mix hot hide glue with enough urea mixed in to have it stay liquid at room temperature. Then when I am ready to glue in the inlay, I mix the liquid hide glue with some sawdust from the wood into which I am inlaying the pearl, making goop. I put some of the goop in the hole, put the pearl in the hole, let it squish out, then I slather some more goop on top. Let it dry thoroughly (overnight is best), then sand flush. If there are any pits, repeat the goop, dry overnight, and sand flush again. I find that, on darker woods like ebony or rosewood, the inlays look perfect, with hardly any hint of the look of filler.

One thing I've noticed about inlays in old guitars, that were presumably installed with HHG, is that they fall out and are often missing.
Most of the fingerboard inlays I use are "dots", and although I make sure they are a tight fit I often drill the hole deeper than necessary. I will place saw dust in the cavity flood with CA and press the dot in flush with the surface. Epoxy could also be used this way and might be a better glue.
I like to use HHG for some things, but not for gluing surfaces that will not absorb some of it.

That makes sense Clay. I do recall anecdotally someone saying that a drop of hide glue on glass actually took some glass away when they tried to scrape it off, so there's that to consider as well.

I've seen inlay missing on vintage instruments as well. I like to use CA but then we don't have 150 year old guitars and banjo's that were glued with CA either, so will it hold up? Time will tell. My guess is that epoxy would indeed hold up for ever though. IMHO there is nothing wrong with using HHG for inlay, it obviously has a track record of working. But with CA... Boom done! Move on to the next thing.

I have heard that too -
https://www.youtube.com/watch?v=G2HQP0jtldQ
https://www.youtube.com/watch?v=P_g_eTXATKg
https://www.youtube.com/watch?v=L4KtLHZfsbM

It does show that there is quite a bit of shrinkage with hide glue that I have also heard works to make our joints a little tighter.
Like J.F., I think epoxy might be the best glue under normal conditions, but as he says - "But with CA... Boom done!"

I can confirm that HHG will chip glass when it dries on it. I have a jar with chunks missing from the bottom when I didn’t clean out the glue when I was done. That tells me that HHG has the ability to hod tenaciously to non porous things. It also tells me that there is a good deal of shrinkage when most of the glue hasn’t been squeezes out by well fitting parts.

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Bryan Bear PMoMC

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

I've used epoxy, tried CA and went back to epoxy. I've seen enough missing inlay on old banjos not to want to even give HHG a try for that purpose. That said, most of the old banjos I've seen (even very nicely made ones) had what I would consider to be pretty sloppy routing for inlay, and when you have a relatively big gap and a glue that shrinks, it's a bad combination. HHG might have worked fine for inlays that fit the cavities a little tighter...

Dave

I like the boom done thing and since HHG has gotten the thumbs down from most of you, I'll probably use epoxy or CA, can't make up my mind. The last time I used 5 minute epoxy to glue the dots in the fretboard, it took a while for it to really get hard.

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Hutch

Get the heck off the couch and go build a guitar!!!!

Maybe Black CA in ebony, it's flexible.
https://www.lmii.com/glue/2978-gluboost-fill-n-finish-pro-formula-black-2-oz-includes-2-whip-tips-and-2-extender-nozzles.html

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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.

You should use what you are comfortable with, but just to illustrate the use of the hot hide glue goop I mentioned above, the below photo shows the results after sanding flush. The material inside the hole in the "P" is 100% dried goop. I think Dave's comments above have some validity; maybe some of the older inlays just weren't that well fitted. In any event, I'm very happy with how my inlays turn out.

The hole looks like it has grain lines, is that an optical illusion?

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Hutch

Get the heck off the couch and go build a guitar!!!!

Great for wood inlays, but doesn't stick to shell. They will stay in most of the time just by the glue forming a fitted pocket, but I did have one fall out once (found it, luckily). Sad because hide glue has such a nice color for filling gaps compared to synthetic glues, and no time limit like epoxy, and no discoloration risk like CA.

You could make it more reliable by filing a few little grooves into the sides of the inlay piece to give it something to hook into, but that would be some fiddly work.

It's a pretty good match, isn't it? I think the illusion of grain lines is caused by the variance in the material that makes up the goop. It doesn't get a uniform brown color; it stays a bit mottled looking, which comes off as grain lines when dry. I had the same reaction as you, when I sanded it back.

One blended approach that might be of interest to you: Use a few tiny drops of quick set epoxy or CA glue in the bottom of an inlay pocket, but not enough to come up the sides of the pocket, insert the inlay, let the adhesive kick/dry, then fill the gaps with hot hide glue goop. Best of both approaches.

I haven't had much luck with 5 minute epoxy. It doesn't seem to ever really get that hard, but it could be poor mixing technique on my part. The stuff that takes longer to set up seems to get harder and sand better.

Pretty much all I have ever done on dark woods is fill the gaps with the appropriate dust and add extra thin CA. Repeat as needed, usually just once. Pretty much invisible.

My approach on light woods is not to do inlays on light woods

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

Wise words! I have done a few pearl inlays in maple. It's tough to make it look as good as I want it to look.

I cheated. 4mm MOP dots, 4mm brad-point drill, press the dot in place with a block to keep the top surfaces on the same plane, a small dot of CA. I don't dare to be fancier than that.

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Peter Havriluk

I agree and I tend to avoid hardware store epoxies and go with the ‘industrial’ grade ones like west system or similar from the boatbuilding trade when epoxy is called for. Of course, these are even more sensitive to mix ratio and technique which has bitten me once or twice when I’ve been lazy or rushed…

I've had good luck with the Devcon 5 minute epoxy for inlays. I studied with some great inlay artists years ago, and that's what they were using. It hasn't let me down.. The only epoxy that has ever let me down was some black epoxy that Stew Mac sold years ago that never set up good and continued to swell up for a long time after it had been leveled. They apparently corrected that problem later on.

Dave

not all CA is the same I use star bond for inlay of small things epoxy if it is a large one but CA is my go to.

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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

When using West system epoxy I am more careful with the mix ratio, which may account for my better results using it. With 5 minute epoxy the usual instruction is to squeeze out equal amounts of resin and hardener (which is done by eye) and often winds up with one tube running out before the other. Something else I was told was a problem, was mixing the epoxy on the surface I was using it on. It is better to mix it first and then apply it to the surfaces being glued. I never had an - inlay - failure using 5 minute epoxy, but rather the fingerboard to neck joint. Live and learn!

Starbond is what I recently bought, thin and medium. Eventually I'll get some thick as well, I'd like to try that for bindings. I love CA, even though I usually get it all over my fingers. It's fun. I stopped using the whip tips and went with pipettes and leave them standing up in a hole when not in use. I really like that because I've had nothing but trouble with whip tips.

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Hutch

Get the heck off the couch and go build a guitar!!!!

Devcon has been good to me over the years. I've even had more problems with West system.

I avoid fast set epoxies these days. Generally speaking the slower the set the stronger the epoxy, and it's also likely to be more water resistant, and less allergenic. I always keep any leftover epoxy, or at least the paper it was mixed on, to check the next day. If it doesn't cure glassy hard it's likely to past it's shelf life, and may be a problem down the road.