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Experiences with Geltack T160

Magnus Nedregard

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I've used Geltack for a while now, really love it for cracks and all that, but I've been worried about it being too strong for tops and backs. Anyone tried to separate a seam glued with this stuff?

Also, I have a feeling it gels much faster than my other hide glues.., not ideal for putting on tops. Last, I've found it works best really fluid, much more so than many other glues, (which makes it particularly good for cracks). But I wonder how much fluidity affects bond strength, with this glue and in general. Any thoughts?

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Recently, I was given a geltack t160 sample by a local violin shop owner/maker and used it to repair open top plate seams on my wife's fiddle. I don't have much experience with it, but was told that it was what he has been using to glue top plates. I should have asked what other applications he was using it for. My guess is that it must have a relatively low gram strength? I can't find any numbers on it. And, I could be dead wrong! It sounds like your impression is that it is a very strong glue.

He suggested using the geltack with a 1:3 ratio, and that seemed to produce a nice consistency.

Magnus - what ratio have you been using?

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Long time no post...

I gave the geltack to Dorje. I've been using it for a year and a half or so. I get it from Ulrich Holfter. He comes to the shop 2-3 times a year, and he was the one who provided me with a sample.

I'll look for my tech-sheet, but it isn't a low gram strength glue. I agree with the concern regarding it's use for tops. I mix it 5:1, or more, for tops and fingerboards, and 3-4:1 for the rest. It seems to have a longer open time, to me, than most other glues that I have used, but when it grabs, it tacks well and strong. It is very clear, as well.

If you go to Ulrich Holfter's wensite, you can get in touch with him, and he can sent it via mail. His US base is at Fred Oster's.


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Yes, my feeling is it is a rather strong glue, compared to other gelatine glues I use... this, combined with its clarity (and short soaking time!) makes it really useful for repairs. So I would be worried about using it for gluing on a table...? I use a rather brittle glue for this.

I wonder if someone knows how the ratio of water affects strentgh in hide glue... it seems logical that it becomes weaker as you add more water, but I don't think it is necessarily so?

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Thanks Duane for clarifying!

I've been using a 315 gram strength glue for the other, more permanent applications...joining ribs to corner blocks, joining plates, etc. It's nice to know that the geltack is stronger than I was thinking...I think I'll use what you gave me with the ratios you mention above for the rest of the build to get to know this glue better. Do you have a sense of Magnus' other curiosity re: the relative strength of the glue when using a higher ratio? It seems that a 5:1 intuitively produces a weaker glue, but is it really the case?

Also, thanks for providing the info on the source. That, I'm sure will help many that want to try the glue an easier shot at getting their hands on it! It's a pretty mysterious product when trying to investigate it on the web...

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Ok, here's the skinny on hide glue...

I posed the question regarding dilution ratios/gram strength to the know-it-all of hide glue at Bjorn Industries, and he said:

1-If you are using 315 gm glue, and you dilute it 4:1, it is still 315 gm glue, but it has less glue solids in the joint and is weaker. He said that he could understand a 4-5:1 dilution for a top/fb, since it would produce a weaker joint, but that he wouldn't feel it appropriate for a joint. He also said that a 4:1 was on the fringes of the "norm".

2-192 vs 315? Higher molecular weight and more glue solids, faster tack, stronger grab for 315. 192-Lower molecular weight (duh...), ect...about 45 sec longer open time in a warm space, but that both would provide a strong bond.

I am still looking for the tech sheet on the Geltack Technical Gelatin, but I still feel it to be 190something.

Is, I ask, there a practical difference between 192 and 315 for our purposes? Violins, that is.


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If you are using 315 gm glue, and you dilute it 4:1, it is still 315 gm glue, but it has less glue solids in the joint and is weaker.

Sounds logical, at a certain point there is not enough glue there, you can't glue stuff with water, after all! But on the other hand when there's too much glue between the surfaces I guess it also weakens the bond too. When taking apart old cracks glued with really thick hide glue, nothing is easier and I am always grateful to this person from the past using his glue at jam consistency.

As an alternative to GT I've tried something Kremer calls just "technical gelatine", I have feeling it is rather brittle when dry, but clear and fluid in the extreme. I have a feeling joints "snap" a little to easily... they have a data sheet however, but I can't find any info about it's strength there...?

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I called Kremer to ask about the strength, after reading the data sheet, and was told that if it wasn't on the sheet that they didn't know it!

Having read the data sheet-completely...-I think that Magnus may have the "secret" without knowing it:

It's made from Italian pigs!

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