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mzuch
05-04-2011, 02:26 PM
I took the plunge into hide glue today. Well, not literally. I used HG to affix the bridge to my #7 tenor nearing completion. A few questions for those experienced with the stuff:

1) What do you use to keep HG warm (145F) and liquid while working? I bought an inexpensive crock pot to use as a double boiler on an Internet recommendation, but the thermostat at its lowest setting allows temperature swings between about 130F and 170F, which can't be good. The Stew-Mac and LMI glue pots are very pricey.

2) What proportion of H20 to HG granules do you use? The Behlens can says 1:1, but several sources on the net recommend 2:1. Any disadvantage to the 1:1 ratio?

3) How long do you typically have to complete an operation before the HG starts to gel? It seemed to go pretty fast when affixing the bridge. I can't imagine having enough time to glue on a soundboard or back.

4) How long do you keep a batch of HG before discarding it? I only use a little at a time, and a small batch could last me months, but I want to avoid problems down the road.

Thanks in advance for the help. Hope to see some of you at NYC Uke Fest this weekend!

Allen
05-05-2011, 12:20 AM
First off there is just so much BS out on the net about what you can and can't do with hide glue from people who never use the stuff, but somehow become experts on it's use because they read a little about it from some internet site from some other uninformed individual.

Hide glue will last you ages if you keep the jar refrigerated between sessions. I've a mate in Western Australia that has the same batch going for 2 years now and still is clear, clean and works as good as the day it was made. Mine doesn't last that long because I use it up a fair bit quicker than that. I've never had a batch get to the point where I'd discard it.

I have a commercial glue pot now, but I use to use a baby bottle warmer prior to acquiring it. I passed it along to Liam, who uses it now. Got it from an OP-Shop for $5. Kept the glue at 140 all day long. There is nothing bad that is going to happen to your glue if the heat goes up to 170 for a bit. Just don't want to keep it there for days on end. Frank Ford (one of the best repair guys out there) advocates glue heated up to 180 in the microwave in a small batch for some jobs.

As for the amount of water to add, it really depends on the gram weight of the glue, and the job at hand. Behlens is 192gram strength as far as I know, and I usually have that glue at about 1.5 water to 1 glue. Anywhere between 1:1 and 2:1 will put you in the ball park for most jobs. You can even thin it out to 4:1 for sizing a joint prior to applying full strength glue. Such as on end grain where it will just such in.

Your open time is dependant on ambient temperature, temperature of the wood, and how quick you actually close the joint. For instance, if you coat the head plate veneer and head stock with glue and lay the veneer on the head stock, you've closed the joint and you've got lots of time to get your clamps in place. Same goes with a brace etc.

And to glue on a top or back is really dead easy. I've got a mate that builds double basses using only hot hide glue. And all my guitars and ukes are built with it. If you run into time issues with hide glue you can size both sides of the joint with hide glue. Let dry if you like. Then position them where you want. Take a pallet knife dipped in fresh hide glue and slip it between the join a little by little. Applying clamping pressure as you work your way around. You can also position the parts together while still wet, and use a hair drier, heat gun or steam wand to reactive the glue.

Same goes for bindings. And if by chance you have a binding that doesn't quite pull tight after dry, you can add a little fresh glue to the gap and apply more clamping pressure. Try that with Titebond....just don't work.

I find that the people that have the most problem using hide glue are the ones that have read too much about how hard it is to use. In my classes none of my students even know what hide glue is, so they don't come with any preconceived issues about it. Hence it's just dead easy for them to use. And after they've seen how easy it is to use, when I give them an option of Titebond or hide glue, they all want to use the hide glue. Last year I taught a class to 12 high school students that each built a concert uke in a week, using nothing but hide glue. All that they know is that is how they are suppose to be built

Now I've got bottles of Titebond going out of date. The hide glue is still good to go though.

Liam Ryan
05-05-2011, 01:42 AM
I don't measure the temp any more. I figure hide glue comes in two states: solid and liquid. In my baby bottle warmer it's liquid. In my ukes it's solid. When my little brush swirls in the warm jar it's at the right temp.

Mixing I follow a similar theory. If I want to wick it in to a gap I water the whole jar down. If I want it to be thick and stay put I leave the lid off and evaporate out some water. It doesn't take long.

As for used by. I found a jar I left on the bench for six months once. It had mould growing on the surface. I threw it out just to be on the safe side. Other wise I just keep mixing more into the jar as I go. There could be bits of the mix that are a couple of years old by now.

Tarhead
05-05-2011, 01:53 AM
+1 on the Baby Bottle warmer. I found an adjustable one (Parent's Choice) on Craigslist for $5. Check the Kids resale/consignment shops too. I use a small baby food jar and when finished it goes in the freezer. Setting #2 gives me a steady 140f.

http://www.ncwoodworker.net/pp/data/1720/Bottle_Warmer_003.jpg

dustartist
05-05-2011, 06:16 AM
I use a Crock Pot Little Dipper. Keeps it right at 140 degrees for me. $20 at Bed, Bath, and Beyond. 2:1 works for me pretty well. I don't like it too thick. Depending on how cold the shop is, it gives me about 2 min. open time, and another minute or so closed. Plenty of time to place the bridge and get it clamped if you have rehearsed your operation.