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Greetings...

When your premixed hide glue is in the fridge waiting to be reheated, what is its form like? Is it dried like cured glue, glass like and crystalline, or a goopy gelatinous mess?

Firm jello.

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Jim Watts
http://jameswattsguitars.com

Solid but squishy. Sort of like rubber. Jim's firm jello description is also good, since that's basically what it is

Ok thanks. Mine too. But then I wondered if it was supposed to be glass like. I've had a few bridges come up and wondered if I perhaps had bad glue. But no, I can once more rest assuered that it's something I've done:)

Mine is 315gm strength glue and it's very firm gello like.

If your bridges are lifting and you're certain your technique is good, perhaps you are making the glue up a bit too thin.

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Allen R. McFarlen
Barron River Guitars & Ukuleles
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Cairns, Australia

That's my best guess.

You can always test your theory by using Titebond to glue a couple bridges, using the same preparation techniques. If they stay down, the evidence is that the glue is to blame.

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It will probably be alright.

Yeah, I switched back to TB. Thing is, they stayed down for nearly two years, then suddenly a rash of them in different circumstances all over the place. Go figure...

Pure speculation here:

I wonder if the crystalline nature of dried hide glue, combined with a relatively stiff bridge, combined with a relatively flexible top and bridge plate, combined with a fair amount of relative humidity variation, and combined with something less than a perfect fit of the mating parts, could lead to this type of failure.

If the top and bridge plate are swelling and shrinking, getting rounder and flatter as the RH fluctuates, but the bridge is pretty stiff, staying flat, I can see hide glue letting go if the joint is not spot on at all points that feel the stress.

"If your bridges are lifting and you're certain your technique is good, perhaps you are making the glue up a bit too thin."

For gluing bridges I like the glue to have the consistency of treacle. For gluing violin plates I like it to be thinner. Changing the viscosity of the glue and the ultimate strength to suit different uses is one of the great things about hide glue.

You might one to test your batch of HHG, on scrap for 24hrs and then see how easily it will steam apart

Ditto.

I don't actually know what treacle's consistency is. But I'm 90% sure I've been making my HHG too thin.

Treacle's consistency is similar to syrup if that helps.

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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.