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When I heat my HHG in the double boiler, the glue is always 15-20 degrees (F) below the temperature of the water. So, when everyone talks about 145 degrees (or so) as the proper temp for hide glue - are we talking about the water temperature or the glue temperature?

It's not much fun keeping the thermometer in the glue, it gets in the way of the brush and obviously gets yucky. So, do I figure out what higer water temperature gives me a glue temperature of 145 and then maintain that or would I be overcooking the glue?

Most people "say" glue temperature but all the pictures show the thermometer in the water and show the temp at 140-145.

I discovered the same discrepency in temperatures. My thought was the the glue is supposed to be 145 degrees F, so I raised the temperature by using a cover over my glue pot.

I keep my water bath at 140*. At that temp, the glue should be the consistency of honey and then you are "good to go."

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JJ
Napa, CA
http://www.DonohueGuitars.com

Yep, no more than 145. I just sit my bottle or glass jar directly in the water and I like mine around 140. I've noticed that HHG stays well liquified even at 120. You don't want to over heat the proteins in the glue...

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I'd like to be able to prove, just for once, that money wouldn't make me happy...

I keep the water in mine at between 145 and 150 which gives a glue temp of 140-145.

I noticed that too but I also see that the longer the pot is on and the glue stays in it, the temperatures seem to even out and get closer to the same. I think if you heat it up until it has the consistency you want then you good to go as long as you brought it up to the correct temp when you prepared it. You can use it at less than 145° as it seems to melt at around 100° or so. My little glue pot won't go below about 150° so I'm glad the glue stays a little cooler.

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Tickle your guitar daily, and it'll tickle you back.

I was told that 140 is the _maximum_ temperature you should have the glue at, as that's the temperature thhat really starts to denature protiens. As long as it flows it's good to go, although obviously it will stay liquid longer if it starts out hotter. It will also break down faster. I don't think the old boys worried about it as much as we seem to.   

If you put the glue in a plastic squeeze bottle or a closed container the glue will stay closer to 140°. You can also put a stainless steel bolt in the bottle or jar to maintain the glue temp while out of the hot water. You don't want the glue any hotter than 140° as it will break down.

An 'aside' regarding HHG is that it's used to make gluechip glass, which is a treatment that distresses the surface of glass. You can try it by spreading or painting some window glass with HHG and setting it out in the sun. It will actually tear glass chips off the surface as it dries. A good demonstration of the power of HHG.

CrowDuck

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Chris Nielsen
Soquel, CA.