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I was discussing HHG on another forum and a member wrote the following:

"if the HHG joint is not very tight its been shown that fungal spores can intrude causing breakdown as fungus can and is its main purpose in nature to break down organic material. For this reason guitar factories use it for sealed to outside air joints like dovetails."

Has anyone heard of this contamination before?

I also disagree that manufacturers only use HHG for sealed areas.

I pointed him the Martin's Authentic Series web page where they say that the guitars use hide glue construction. I'm assuming Martin is using HG for more than just the neck joint.

Well, the protein in the glue is food - so it makes sense that fungus may find it attractive. I've run across fungus in glue joints a few times, but not many. All the joints were repairable by removing as much old glue as possible, cleaning the surfaces to be mated as well as I can, and then re-glueing them. It never occurred to me about preventing such fungal infections, I figured it's just natural. It could be worse - the fungus could eat the wood, and that would be a lot more work to repair.

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"Act your age, not your shoe size" - Prince

Thanks, Chris.

If you recall, which types of glue joints did you find the fungus in?

The member was discussing a headstock break of a Fender 12-string that was repaired by a violin luthier using HHG and that the fungus attacked the glue joint causing it to fail a second time.

I wonder if it the fungus is probably already in the glue when it was put in. Mixing fresh glue if the glue you have that is mixed up is a week old, or has a bad smell, or every time you use it, is probably a good idea. I use distilled water all the time now. I don't trust my well water. I like pouring any leftovers into a plastic medicine cup; I never mix much; a tablespoon maybe. If I leave it in the brass thing I heat it in, and it sits for a while it goes bad; then I have to clean the stinky mess up. It rarely goes bad in the plastic cup, but if it did/does, I can just pop it out, clean it, or grab another cup, and I'm good.

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Why be normal?

Fungus will not grow without moisture. An environment above 60% relative humidity can have mold growing on organic materials but below 60% it will usually not unless the material itself contains water (such as cheese). So the take away is to keep the guitar dry and there will be no problem. I read that they pulled furniture out of King Tut’s tomb that still had tight joints that had been built with HHG. And we know that Egypt is very dry.

Interesting thought, Ken.

Good point, Barry.

I'll ask the other member where the guitar was located.

You can’t tell why the repair failed without examining it yourself. If it didn’t fit perfectly, the 12 strings would have been a good challenge for it. As it gradually opened, the spores could have had an opportunity to get in there and make it look pretty funky. I have heard that artifacts from the pyramids were glued with hide glue 4000 years ago and still have intact joints.

I think that if you make good joints with good hygiene you won’t have problems with HHG. The 135F working temperatures won’t kill every organism, but it will kill a lot of them.

I didn't know you were a member here.

Where was the guitar located?

Dan, do you have me confused with someone else? I understand that there’s another Bob Gramann in California who is also a musician.

Ha ha! Looking again, the other guy's name is Paul Graumann. So, yes, I do have you confused with someone else.

I think it's a one off we've repaired over 20,000 guitars in the last 20 years and I have never seen HHG attacked by fungus.

Not saying it can't happen and if the glue was contaminated (you have to watch out for those violin makers.... ) and/or the instrument was kept in a fungus infested environment what Chris said comes into play, HHG is food for some organisms including us, humans.

Funny, a couple times, I've had instruments played at the MVA meetings. Once David Burgess was using my instrument to show how string angle could change sound with a contraption that he made, changing the saddle height, so the string angle. The back or belly cracked from the pressure. The seam broke loose.

At the April meeting at the Ferrari dealership in West Bloomfield, the president of the group was playing my Cherry 5 string, very quietly, and listening intently. He put it down after a little while and went away before I had the chance to tell him that the back was pulled away completely from across the whole bottom of the block! It still didn't sound bad, i just noticed it after someone gave it back to me after playing it. They were just as surprised as I was that it even played that good.

I didn't notice it until I was in the building. It was raining, but probably very dry inside?

Really? Always at the worst time.

At the same time I've had all kinds of trouble getting HHG joints loose to get the back off the little Les Paul archtop, to beef up the bracing on the belly. The upper block was really on there.

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Why be normal?

Easiest guitar disassembly I've done to date was a '49 J45 that was stored for some years in a shed in rural Alabama. Obviously a real humid environment. Some of the glue joints had a blue look like they may have had fungus or mold or something growing on them, in most of the joints the glue was just powdery. Most of the joints separated easily with a pallet knife.

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Steve Smith
"Music is what feelings sound like"

Without seeing the instrument, I would be more suspicious that condensing humidity and heat did it in. I have been amazed, visiting pro-luthier shops, to see vintage instruments reduced to a Rubbermade tub of parts by a few years in an attic or shed.

One I remember, in particular, was a middle aged woman walking in with a cardboard box full of parts. Neck, back halves, sides, an unbraced top with the whole tol seam flopping loose except the rosette, and a pile of blocks and sticks in the bottom. She said it was her father's. They chunked it into their coastal Florida attic, and ten years later, were shocked to find nothing but parts and a lot of tan dust.

But so it goes.

Thanks for the input, everyone.

I'm in agreement that the failure of the headstock repair is most likely caused by the environment in which it was stored and less about fungal contamination of the glue, itself.