Official Luthiers Forum!

question about ground hide glues...what kind of odor do they have after setting? is there a cure time during which smell dissipates? what would a joint made with them smell like 4 months, 6 months, a year on? thank you from a chemically sensitive guitar player.

Should be odor free after setting up. Even during preparation, quality HHG, should be very low odor. Kind of like LePage's kid, craft and hobby glue if you are old enough to remember.

It should only smell bad or strongly if it was poorly made or sat in the glue pot too long. If it stinks, it is rotting IMO. If it's rotting you shouldn't be using it because bond strength is diminishing.

_________________
Brian R, Wood Mechanic
N8ZED

After setting they should have no odour. However, when sitting in the glue pot the smell depends on the quality of the glue. Some have hardly any smell, others will smell enough to make you puke. The locally made stuff we have here is of the latter variety and hide glue is now a prohibited import so I can't import the good stuff legally. I am still using hide glue I bought from LMI many years ago when it was not prohibited that does not smell much at all in the pot.

The end user will not smell hide glue used to construct an instrument. If you are chemically sensitive, you have much more to worry about from the average finish material than from hide glue. Even if you were in a room with hide glue while it was being used to glue something, you would, at worst, smell something like a strong food smell. There’s no chemical smell to set off your sensitivities to chemicals.

The 192g hide glue I bought from LMI is next to odorless. The 315g BT&C hide glue has an unpleasant odor when hot and wet. Both are totally odorless when cured.

The bt&c stuff I have smells like death on a stick if you leave a little in a closed mason jar on your bench for a couple weeks.


Sent from my iPhone using Tapatalk Pro

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

if the finish is dried and cured and has no smell on the outside of the guitar, is there any possibility that it would wick through the wood and smell from inside the sound hole months after manufacture? What about treatments to condition the wood before assembly? I have read that some toxic chems may be involved there. Could there be lingering odor of that?

192g high clarity is the lowest odor I've found, and even that is quite pleasant.

HHG is an organic substance, basically equivalent to a bacterial growth medium once it is made up. Keep it in the fridge between uses and throw it out if it smells.

Once I put half a tuna sandwich in a mason jar, left it on the bench, and opened it up a couple weeks later and PHEW, that tuna must have been no good!

Brian

_________________
Brian R, Wood Mechanic
N8ZED

I wouldn’t worry about the “bleeding through the wood” issue; you have more significant things to worry about, depending on the finish material. If you don’t like lingering chemical smells, don’t have your guitar finished with nitrocellulose lacquer. It is always offgassing. If you are having the guitar built for you, discuss your sensitivities with the builder. The builder can use hide glue for the adhesive and shellac for the finish. Both can be done with zero added chemicals. The solvents are water and grain alcohol, respectively. Note that I’m taking your chemical sensitivity seriously. Some people develop that. If you merely don’t like smells, that’s different.

I have an old can of Behlen's 150g that smells like a wet dog when heated up, but the LMI 192g is very mild. LMI's also seems quite decay resistant. I've had a plastic squeeze bottle of fully hydrated glue sitting out for several years, and last time I heated it up and glued a test piece, it was still able to pull a chunk out of a piece of walnut.

Joints never smell, but if you leave a lot of residue on surfaces inside the box of a guitar made of low-odor woods, it may be detectable to a sensitive nose. But residue can be removed with a wet rag even after the glue has dried (one of the many handy properties of hide glue), so that should never be a problem.

Hide glue is animal gelatin, with some impurities because it is made by rendering down animal skins, hooves etc. The more impurities, the stronger it smells when wet.

When dry it is odourless.

If you smeared a lot of glue inside a guitar, and the inside got wet, it would smell faintly of a mixture of skin, hair and nail clippings. The smell would go away when dry.

Animal products like hide glue and shellac never cause sensitivities, so far as I know. This is because they are both edible (though impurities might make them taste bad). The risk from smelling them alone is even smaller!

Can't tell where you are but "bone glue" is commonly falsely marketed in Europe as Hide Glue and Bone glue is like a pre Upton Sinclair Hot dog from a Chicago meat packing house after two workers fell in the vat and they made the result into hot dogs anyway and sold it to your local Coney Island lunch counter.

It's a foul smell and if you are in Europe or the glue that you are using could have come from Europe and smells like three politicians emptying a septic tank (didn't say what kind of politician in my continuing efforts to be non controversial... ) you may have bone glue.

As nearly everyone has said there is very little to no oder from proper hide glue. I can smell it a bit when working with it and the pot in under my nose but I have a huge nose and when I go outside it weathervanes which was great when I used to race Banshees and Lasers.

There are certainly exceptions but Tanex hide glue from the Czech republic is very good quality and very low odour.

_________________
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.

The problem is a severe chemical sensitivity not just smells. I'm speaking of guitars made in the last decade or so which have a certain kind of odor which emanates from the sound hole which I believe is responsible for my symptoms. I have a guitar made as late as 2001 which smells like wood in the sound hole, a very clean smell, and I have no problem with that guitar. Others I have tried made since 2011 have a sort of similar sweet chemical smell that I find not only unpleasant, but is what I am convinced is causing my problems. I assume it's from a glue residue but could be from a wood treatment I suppose. The former was confirmed somewhat for me when, after my repeatedly questioning one maker's representative, he finally admitted there was a glue used that I discovered is a known carcinogen. Finish on the outside I am not so much concerned about because there is no detectable odor there. The main problem I am dealing with at present is a higher end guitar I recently purchased from one of the mid size companies specializing in a limited variety of 6-string acoustics. The rep assured me before I bought that only ground hide glues were used in their guitars and they had customers with sensitivities who found their guitars acceptable. Since then I have had more than one reason to distrust this company, and the rep later admitted yes some of the glues had strong smells which would dissipate in time, which leads me to believe after reading all the responses here, he was lying to me from the getgo. That is the issue I am dealing with now. In my future purchases I will certainly investigate these matters much more thoroughly.

Well, like I said, I take chemical sensitivity seriously.

Against the unfortunate backdrop of your having this condition, there is good news. As I said above, you can connect with a hand builder who can build you what you want, using the materials, adhesives and finishing materials you want. It won't be cheap, but nothing is cheap when you are trying to accommodate a medical problem like this.

If you are looking for a factory-made guitar that doesn't have "interesting" chemicals applied to it somewhere, you are not going to find satisfaction. All factories use something on their guitars that runs the risk of triggering your issues. It's just the nature of mass manufacturing guitars. Sorry for the bad news, but it is what it is. Most folks don't have a bad reaction to these chemicals, so products get manufactured for them, not for you.

Unless consulted ahead of time, hand builders tend to use a lot of chemicals, too, so you need to talk to the builder about things that might trigger your reactions. The good thing is that a hand builder is less likely to mislead you and more likely to accommodate your issues (for the right price).

Good luck!

I assume you've already checked that it's really the guitar bothering you and not the case? Hard shell cases tend to smell very strongly of chemicals when new.

Also when kept in an enclosed space like a case, finish smells can accumulate inside the box even when sniffing the outside of the guitar isn't strong enough to detect.

I'd be very surprised if it was the hide glue in the second guitar that was the problem. Even if you are able to pick it up, it has a very "natural" kind of smell, not at all like sweet chemical smells.

I very much doubt that hide glue is causing your problem, once dry it is odourless and does not contain nasty chemicals. Wood is not usually treated with any chemicals before being prepared for a guitar. There are lots of other things that might be causing the problem, including the case which often have volatile glues that can smell quite strongly and the smell permeates the guitar. Some finishes have volatile solvents that continue to outgas for months or years. You might not be able to smell the finish from outside the guitar, but it can still be detected if you sniff the sound hole. Then there is the wood. If the guitar is rosewood then it will smell like rosewood for a while. Eventually it will smell like old antique furniture, but that will take years. Many other woods have an odour that is distinctive to the species of wood used in the guitar, and that smell can take years to dissipate. What you smell in the sound hole is a combination of all those things. A new guitar won't smell like antique furniture until it is many years old, no matter what glue is used.

I just sniffed my old classical guitar I have had since I was 15. Smells like old antique furniture. Also sniffed a classical I made about 6 months ago. I can smell rosewood and varnish, and a bit of Spruce smell. Can't detect any glue smell.