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Well, the week before last, Tropical Storm Betty slowly tripped and stumbled around my neighborhood for almost five days. It started Friday evening and didn't let up till Tuesday afternoon. My rain gauge says we got a little over 18" of rain in that period. That's a lot of rain. Anyway, after it let up, I wandered down to my shop (it's in my barn, about 150 feet from the house) to bind a Cocobolo/LS Redwood OM I've been working on. I'd already cut the binding and purfling channels, I was just waiting for the weather to improve to get back to work on it. But when I opened the shop, I found that the top had completely separated from the rim except for a small section around the tail block. Crap. I used fish glue on the top exclusively.
What was the humidity, you ask? I have a digital and an analog hygrometer... they read 89% and 91% respectively. When I got the top completely off, I also discovered that the bottom 2 or 3 inches of the lower x-braces had also separated. My shop is de-humidified by a window style air conditioner. I had upgraded to a larger unit this spring and it kept my shop a workable 45% to 50% RH. We had a short power outage Friday evening due to some lightning and the air conditioner obviously had not re-started. As far as I can tell, the humidity had been hovering in the 80-90 percent range for the better part of 4 days. It's interesting to note that I have a finished Dread body in the shop too. I used fish glue for the top and back, but used HHG for the bracing. I haven't gotten around to fitting the neck, but it's got a dozen coats of lacquer so it's pretty well sealed. It was unaffected (as far as I can tell). I also have a pair of braced L-00 tops I put together with HHG... they're in good shape too. I've been using fish glue for more and more things these past few years and I've been really happy, by and large. But like a lot of folks, I've wondered how fish glue compares to HHG, PVAs, etc in high humidity situations. I'm pretty sure I don't have a definitive answer, But I do have some things to think about. I believe I'm going to do a little testing to put my mind at ease before using it again.

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Jim Womack

"Be thankful we're not getting all the government we're paying for. "
Will Rogers

It wasn't hot. The highs were in the low to mid 70s for the duration. I believe a contributing factor, humidity aside was the routed edge. I believe the exposed kerfs allowed the humidity greater penetration into the joint. I think.

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Jim Womack

"Be thankful we're not getting all the government we're paying for. "
Will Rogers

Very interesting report Jim. Sounds to me like the easy access of the humidity to the joint, with the wood being unsealed allowed this to happen.

Don't know what to think of fish glue.

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Joe Beaver
Maker of Sawdust

Just do the tests. It isn't difficult to recreate the Humidity that you are referring to, a sealed plastic bag will do. Glue a few pieces of wood together. Test. Throw in a few 'contols' such as HHG and Titebond. Doesn't take long.

Thanks Jim this is a good heads up.

Failure of fish glue at the higher ranges of RH has come up a few times. But there always seems to be two other variables which can come in to play to muddy the waters a little.

The first is the age of the glue. Fish glue 'appears' to have a use by of just a couple of years and this factor more often than not is the first spanner in the works of clarity in the debate. The second is the unsettling 'settling' of the glue.

I have had some in my shop for a while just to watch it and sure enough if you leave it be you can easily see how this glue does settle out with a lighter 'milky' coloured layer gradually forming at the bottom of the bottle. Now in past debate this settling has been blamed for bond failure with some arguing that rather than age or RH, it is a failure to mix the glue prior to use that had caused their past problems.

So for clarity, could you please let us know if either of those two things could have contributed to your own recent experience.

Cheers

Kim

Mhmm...I've kept samples in the bathroom for extended periods and they all held fine at break tests even if the squeeze out on the outside was soft and tacky. I think the bathroom test is beyond reasonable use for a completed guitar.

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Build log

I have done similar tests, leaving samples outside on the back porch for a week during high humidity and had the same results. Joints held fine even though squeeze out was soft.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

I have been using Fish and Hot Hide for years now without issues. Always check glue that has been stored as this does have a shelf life. Most glue failures are more to technique than the glue , unless the glue has spoiled. It can be stored frozen to lengthen shelf life. I won't glue up anything over 50% .
I think your structural stresses from the high RH may be more of a culprit than the glue you used.

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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

Filippo, that's been pretty much my experience too. I pretty much use it for everything now, although I still like HHG for bracing. I can't remember the last time I reached for the Titebond. I especially like it for repairs. Easy clean up, nearly invisible glue lines, longer working time, etc. The thing that nags at me is that the HHG joints on my L00 tops were unaffected. No softening at all.

The glue I'm using is more than two years old. I haven't noticed any settling. I'm pretty sure the glue's OK, but I've already ordered another quart. I do want to do some test glue-ups with the old and new glue to ease my mind.

What would you guess the shelf life to be, John? I would guess a couple of years but I'm not sure. I do store my bulk glue in the fridge (not the freezer) and pour out into smaller squeeze bottles as needed.

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Jim Womack

"Be thankful we're not getting all the government we're paying for. "
Will Rogers

JJ (you guys remember JJ, don't you?), did some pretty extensive testing of FG a couple of years ago. One of the things that he found to be very important was to always either stir or shake the FG until well mixed, before using it. The settling does have some impact on the strength of the joint. I, now, treat it like HHG, and decant to smaller bottles with stainless nuts in them. This agitates the glue, which is hard to shake without some help, it's so thick.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

JJ? JJ who? I seem to recall that name, but can't quite place the face anymore.

I've been using the Norland's fish glue (I assume that's what we're talking about) exclusively for two current projects, a BRW/Adi OM, and another Smiley-Uke (TM). I love the stuff as it is so friendly to use and clean-up is easy. The ukulele is for a customer, and the OM is for me (unless someone want to pay me a bunch of money for it), so I sure hope I don't experience any of this.

I've also been using it for gluing down pearl to cut on my cnc, and it's great for that. It releases nicely in boiling water, so for me I know not to drop an instrument made with fish glue in boiling water. Beyond that...I guess I'll find out.

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

Yes, that was just a friendly ribbing aimed at JJ, should he show his face around here and read that...


He's been very scarce since meeting the new love of his life.


Back to the fishy glue...I love the stuff. I also like poly glue for some things as you mentioned, like laminating darker woods instead of using titebond or epoxy. I still reach for Smith's Tropical Hardwood epoxy for oily woods like cocobolo, but it's fishy glue for me for bracing and general assembly.

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

Jim,

What I have learned from this post (other than the info on fish glue) is that you need to go ahead and just put a neck on that Dred. You know you want to. My prediction is once you have the neck on, it will become your go to guitar. Indestructible. It will be the one you pick up and take with you when you flee for any number of issues such as:

Hurricane
Tropical Storm
Monsoon style flooding
Swamp Gas
Termite Invasion
Alien Invasion
Zombie Apocalypse
In-law invasions
Hound Dogs

There are plenty more, but this is the guitar that will survive them all.

John

After you routed the binding channels, how much glue area was left to hold the top in place? Had you also cut the purling channel? How wide was the lining you used and how thick was your purling?

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Formerly known as Adaboy.......

If there was very little top width on the lining (often the case with wide purfling) perhaps it opened up simply because of the soundboard expansion. From 50 to 80% a free plate curls up to a semicircle, and there is plenty of force in this movement while the bracing can't do miracles.

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Build log

I would have to say that since you didn't have other guitars with other glues it is an assumption that it was only fish glue faliure, I think this situation would have stressed any glue that you used. With the stresses of the wood expanding that much , you have a guitar that was trying to push itself apart.

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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