Differences in batches of Hide Glue

[Steve Woods]

David, how do you use a coffee percolator for this. Does it involve the basket? What is the ideal temperature for 192 HC?

[David King]

Steve,
No need for the basket but I'm sure you could incorporate it if you wanted to. Percolators have switch that causes the water to boil for a set period of time determined by a little knob or lever (It usually says Stronger- Weaker as the range). After that period has passed they drop to a low level heat that keeps the coffee at about 170º with the lid on and 140 if you leave the lid off. I sawed the top 2" off my pot and made a little bent aluminum platform at the bottom to cover the heating element and serve as a shelf for my glue bottle. (An inverted basket could do this). I fill the pot with 3" of water, set my glue jar in the water with a cube or two of frozen glue. I plug the pot in, press the button and once the water has boiled for it's minute or so, my glue is partially melted in the jar. By the time the water has cooled to 140º the glue has melted and heated to 140. You don't want you glue to get much hotter than 145 or you will start to kill it's gram strength. Get a cheap digital meat thermometer to keep track of what's happening in the water and the glue. You can fine tune the system by starting with hot water or keeping the lid on more or less as the glue melts

[Bob Gramann]

I use a baby bottle warmer with a dial and a candy thermometer to maintain a 140F water bath. It's cheap and easy.

[Steve Woods]

That baby bottle warmer idea sounds like a good one. Do you use a baby bottle as the glue bottle? Can you re-heat the same mixture later or do you have to mix up a fresh batch each time?

[Bob Gramann]

I use a two ounce bottle that I got from the craft store with marbles in it to make it float vertically. I keep the bottle in the freezer between sessions. My typical mix is 17 grams of glue in 32 grams of water. That amount will last for several sessions. It's nice to have a bottle with a small spout for direct application, but often I remove the spout and use a brush. When the texture of the glue changes, I pour it out and mix a new batch. Hide glue is cheap--there's no need to risk using bad glue.

[Steve Woods]

I found a $5 old Sunbeam electric percolator today and a meat thermometer according to which the water stays steady at 150 degree on low setting. Is this too warm?

[David King]

Well 150º water bath may translate to 140º glue in the bottle depending on how much heat gets through.
If you can access the base of the pot you may find an way to adjust the thermostat. If it doesn't rely on a thermostat for the warming element you can then control that element with a dimmer switch.

[Steve Woods]

Getting ready for my first attempt at brewing up a batch of hide glue:

[David King]

I see all essential elements are in place. A dish towel with roosters is particularly apropos for the season.

[Michael Lewis]

Put an appropriate cover plate on that electrical box before some piece of metal gets dropped into it or water is slopped into it. Just sayin'.

[David King]

Just wrap a couple of layers of electrical tape around the rear part of outlet to cover the screws for starters.

[Steve Woods]

How long should a mixed batch of glue be good for if kept regrigerated? Nor frozen but kept at about 40 degrees?

[David King]

Steve, that's going to depend on several things, how clean everything is for starters. How cold your fridge is. If you see spots of mold developing or smell an off odor you should toss it and start over. I'd say two weeks if you are lucky.

[Simon Magennis]

How long should a mixed batch of glue be good for if kept regrigerated? Nor frozen but kept at about 40 degrees?

If you have never seen it, have a look at Frank Fords page about hhg http://www.frets.com/FretsPages/Luthier ... glue1.html Actually he has a number of other pages about it to but this one is the key. He makes a batch of glue, lets it set to a jelly (jello) and cuts in chunks which he keeps in the fridge, Some people do the same but keep it in the freezer.

You can keep it for quite a while. You just need to be sensitive to the smell. If the smell changes, chuck it. If mould grows on it, chuck it. I have often keep it for 6-8 weeks in the fridge with no issues. However at a certain point I get risk adverse and chuck it anyway. Frank suggests making enough to keep you going for about 3 weeks.

Actually its time for me to order more. The 1 kilo bag I got about 4 years ago is finally finished and I am using bone glue which I don't like as much.

[Bob Strawn]

If you are interested, I have detailed my setup for hide glue at http://toolmakingart.com/2013/09/30/hot-hide-glue-pot/

I use the ‘la petite’ Melting Pot for Wax, Sugar & Paraffin. This is a beauty supply wax melter for various purposes but mostly putting liquid wax on you so you can rip hairs out. Currently this goes for under $20 on Amazon. It has a light that turns on when it is heating, and a knob to control the temperature. Heats up pretty quickly and then remains quite stable.



Bob