Hide Glue Temp

[Jerry Thompson]

i am back using hot hide glue. I mixed a small batch a put it in a very small crock pot. The temp stayed @ +140d for a good while. I became distracted for about 10-15 min. and the thermometer read +160d. I took the glass container out of the water bath immediately.
My question is, should I redo it or is it probably OK? I am doing some small mortise and tenons in cherry.
It is no big deal to do it over I just like opinions & knowledge about these sort of things.
Thank you.

[Kees Heiden]

160 wouldn't be enough to start worrying. Boiling really isn't good for the glue though, at least that's what everybody sais nowadays.

That brings me to another question. In many old texts you find the man in the workshop "boiling the glue". Usually put it on the stove first thing in the morning. I can't imagine they watched it very closely all day long. Did they really boil at 100 degrees celsius?

[Warren Mickley]

There is nothing at all special about the 140 degrees. The glue deteriorates if kept hot too long. The hotter it is the faster the deterioration. At 140 degrees a workman can keep the glue hot all day long for about a week of use. Some guys make a fresh batch every Monday morning. The glue will last longer if it is not kept warm all the time, but it is also susceptible to bacteria and fungus at room temperatures, especially if it is a little runny.

Hide glue was used for millennia before the invention of thermometers or the birth of Daniel Fahrenheit. Workmen warmed it up for use or kept it near a fire. Some texts suggest hotter runnier glue for some applications, with no reference to temperature at all. I used to boil a small pot of water and place a jar of glue in the water to warm it up before buying a gluepot 30 years ago. I personally only turn on the pot when I am preparing to glue something. And in the winter I sometimes just put the pot on the wood stove and keep an eye on it. I also put parts to be glued on or near the stove if the shop is cool. Even if you use a pot with a thermostat you have to learn to judge the quality of the glue.

[Karl Andersson]

I imagine they have to boil the hooves and hides to get the collagen out (but I could be wrong) - maybe Kee's example refers to using more raw materials than ready-made glue granules? Nah, sounds too messy. Maybe they just called it boiling because it looks like you're putting a kettle on.


I've overheated hide glue for short periods before, and as long as it still made "strings' when tested between my fingertips, I used it and it seemed to be OK. It only didn't make the strings once, and that glue was a little old in the jar.

[Kees Heiden]

Thnaks for the insight. We tend to analyse many things way too much, especially us hobbyists.

[george wilson]

If you get the glue too hot,the protein will cook,and it will not be adhesive any more. I use a small jar that I can sit inside my expensive electric glue pot(too pretty in a utilitarian sort of way to get all covered with glue!). I put water in the glue pot and sit the small jar in. I keep it at about 130º. When I'm done,I put the small jar in the fridge. It will last several days before it starts to stink,and must be discarded.

I recall a story from long ago,where a Piper Cub pilot got stranded way up North in Canada in some primitive village. He had a cracked propeller,and dared not take off over the wilderness. Not a good place to be stranded. One day he saw some natives cooking some moose hides in water,for some reason. The water had become a thick soupy mess. It looked like glue to him,so he took some and glued his prop with it. It hardened up o.k.,and he took off and made it back to civilization.

In Alaska,where I was,there were always "Flying Missionaries" Especially 7th. Day Adventists,it seemed. Many of our neighbors were of that faith. One was indeed a flying missionary. I helped him to recover his yellow Piper Cub with cloth,which he kept in a large garage under his house. There was a huge,long road that us kids used to sled down in the Winter. He could get enough speed going down the road to take off. Things weren't so strict back then,and Alaska was a territory. Or else,he just got away with taking off down the road!

After we left Alaska in 1957,I read in a letter that he had crashed and got killed flying somewhere to preach to the natives.

Another man I knew had a Piper float plane. There was water everywhere to land. A lot more water than land areas to land! I helped him to build a house next to a house we were living in when we first got there(The rest of the time,we'd bought a lot and spent 3 years without lights or water while building it,making a road to it,and burying water pipes 4' deep(They'd freeze anyway,so every morning and evening I'd have to chop open the box that had a faucet about 2' down(always full of water). I'd have to take off my parka and reach down into the freezing water and turn it on or off,as needed). Well,this guy crashed his plane showing it to someone he was going to sell it to!! Very bad luck. At least they lived.

But,I digress from glue. If you want to see a good discussion of glue,and have access to the FWW site of videos,go there and watch my last remaining apprentice,Ed Wright(now journeyman) discuss glue.

[Jerry Thompson]

Thanks everyone. I will still be anal retentive but less so on this subject.

[Craig Regan]

What do you have a picture of Hillary Clinton? Is she a woodworker?

[george wilson]

She works anything she can.

[Craig Regan]

The moderators should limit avatars to wood working or family themed pictures.

If you want to express your political views on Hillary Clinton then find the appropriate web site for that discussion.

[george wilson]

Thank you for your guidance,Craig. But,as long as it is not obscene,I think everyone has the right to use any avatar they feel like. An avatar is not a political statement necessarily. She's making a funny face. Want to police humor too? My remark was humor.

BTW,WHY family themed? Is this a woodworking family? Sounds a bit selective to me. And not smacking of freedom.

[Stewie Simpson]

My understanding fits in with what Warren has already mentioned. 140* f (60* c)

[george wilson]

I think 140 may be pushing your luck. But,if glue still holds cooked that high,I guess it works. Unless it might have held stronger cooked a little lower.

I haven't made a science of it. I just know what I'm comfortable doing. My glue has to be as good as possible,because stringed instruments have a lot of tension on them,and precious little glue surface.

[Randy Karst]

Very reasonable George.