Official Luthiers Forum!

I was reading a "Woodworking" magazine at a bookstore yesterday (I guess the current issue) and it had an article about two brands of liquid hide glue. But the author also talked about mixing your own from the granules. He said if you mix 1 part glue, 2 part water, and 1 part "salt" that.....for one, the glue had a longer shelf life as it would prohibit molds from growing and, two....at room temperture it would stay a liquid.
Have any of you hide glue users ever heard of that?
I'm about to mix up a batch and see what happns.

Jeff

I've always used hide glue in a 1 to 1 ratio by volume water to granules, never added salt and keep it in the fridge when not in use. If I go over 10-14 days then I toss the old and start over with a new batch. Everything I've ever read says to keep the mix at that level. I'm sure it would be "runnier" under a 2-1, but my concern would be strength in the long run. I've found that stretching materials by adding water only seems to work well when making soups or serving expensive liquor to intoxicated persons (ie: add more ice)

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Bobby Masten

Instructions on the hide glue that I use (from LMI, I think) are 2:1 by weight - water to granules. This seems to end up being very close to 1:1 by volume. I think they probably don't advise that because of the difference in density due to granules settling more when they are finer (at the bottom of the canister). I also refrigerate when not using, and throw it out after 5 or six heat/cooling cycles.

Never heard about mixing with salt. Suspicious about anything that would alter the chemistry to keep the glue in a liquid form.

I'd think if you were going to go for that, why not just go with Titebond or LMI white.

I sure would never add salt to hide glue. I can see the salt desolving in hot water but as the glue dehydrated I would expect it to crystalize. Urea is often used to dlay set time.

Pass the salt? No thank you...

Adding a little salt will extend open times, and I can't tell it makes it any weaker in small amounts. I suspect the amount mentioned in the article will weaken it, or cause other problems like Michael mentioned. I use a pinch in my mix for closing the box, but use "salt free" for everything else. I learned the "salt trick" through a couple generations from my Great Grandfather. He also said to put a drop of vanilla extract in it to help with the smell. Even with the vanilla extract it still smells........bad when it's bad. He mixed equal amouts of water and ground glue, by volume. I weigh it 1.8 water to 1 glue.

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

Jeff,
mix up a good sized batch (by weight as is traditionally instructed on the container.)
Then cut the batch and add salt to one of the batches.

Do a test on a couple scrap boards. See if there's any difference between them in terms of holding power when you try to tear them apart after a few days of curing.

report back here. I'd love to know how this turns out.

From what I've heard, salt is an age old method of extending open time, in a lot of woodworking venues and not just lutheiry. Most of us are just nervous about trying it because we didn't learn to do it from whoever we learned the art of HHG from. That doesn't mean it won't work.

Take the lead on this one and let us know what you find.

Dave

Hi Dave,
I mixed up a batch yesterday and cooked it for two hours...the article said to cook again the next day for two more hours. I did try it out on some scrap and the open time is alot longer. The salt did not desolve during the two hour cooking...it settled in the bottom of the bottle and I would stir it up ever so often.

I thought the article was somewhat interesting and thought some of you may be interested as well.....

I tend to agree that to manipulate the chemistry of the glue may not be a good idea, but...one will never no with out doing some test pieces.

Salt sounds like a good idea.
To extend open time I mix 1:1 HHG and Franklin liquid hide glue in a separate jar and heat it up like I would HHG. It takes a lot longer to cure, but seems as strong. I use it for linings.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/