Let me point out that I’ve made liquid hide glue in the past using urea, but I’ve never used salt before. Making a batch that would cause having a no shelf life was very exciting to me, just goes to show I got no life.
started off with the ingredients from Mortise and Tenon coupled with the methods used by Don Williams. I followed it to the letter and doubled cooked it twice over a two days period as Don does. Everything looked good, even the viscosity was bang on.
This surely was a good sign. I did a test glue up and I dabbed some glue on a piece of scrap
Starting from the left is Titebond LH, it took 1 week to cure, then fish glue from Lee Valley that the bottle is out dated but cured over night. For some reason fish glue doesn’t seem to spoil. I had fish glue that was many years old and worked as well as the day I bought it. I have no answer for why it doesn’t spoil. Next is the outdoor PVA white glue that I’ll use to make some planter boxes. It too dried over night. Next to it is hide glue straight from the pot and that dried fast and hard and finally my LH and hasn’t yet dried even though 6 hours have passed. I can’t blame the glue for being old and I didn’t overcook it but I feel that adding 2 teaspoons of salt which equals 11.8g was way too much and that’s why it hasn’t dried yet.
I will paste an email I got from Don which will demystify why it hasn’t dried and what the deal is with Titebond LH and why it didn’t cure. I hope this email will answer many questions you will actually never find on the web.
Great to hear from you again.
My experience from a practical matter is that there is no shelf life limit to glue wherein the gel suppressant is pure canning salt. The Inevitable terminus of the shelf life in this case is microbial, as long as there is no mold in the batch it seems to work fine. Exactly what proportions of salt to dry crystal is something of a mystery, I have not found nor created a reliable recipe that works for every situation. I mix it up one small dispensing bottle at a time (usually a new condiment dispenser bottle from the hardware or home store) and add a healthy pinch or two of salt to the mix after I have the liquid glue fully soaked and double cooked. At this point in my work I am not necessarily looking for a literal “room temperature liquid” hide glue, I do not mind warming it a bit and just exploit the much longer working and setting time provided by the salt gel suppressant.
The reason some commercial liquid hide glues have shelf life problems is that they use urea as the gel suppressant, which is not a problem if the batch is fresh. However, over time the urea begins to “unzip” the protein chains, eventually to the point where the glue will almost not dry at all without the input of heat.
Let me know if this is helpful to you.
Absolutely Don this information helps. I’ve learned a tremendous amount just from one experiment and I can’t see myself doing another. Reason being its cost prohibitive. Hide glue is bloody expensive, it’s not expensive for you yanks but for us poor sods living down under and for those living in Europe it’s expensive. It’s mostly the shipping fee that kills it. For me to get it over from the States from Patrick Edwards I would spend $100 in shipping and that’s for 6 pounds. I don’t know how any postal service can justify this amount, but that’s what it is. I can get pearl glue here for much less and the bloom strength is 200, which is on par with what I’m using now. I prefer the stuff I’m using now because it’s from Milligan and Higgins. I’ve only ever used their glue, and I trust the source and know its reputation. But I guess that’s my fault for only ever exposing myself to one product. Then there’s the issue where now US companies are backing away from international shipping because of the excessive shipping charges and the dilemmas involved with damaged goods and what not. It’s funny when you think about it. In the beginning the world was excited that it will sell their goods across the planet and now they’re shying away from it. As far as the test pieces concerned, I will find out tomorrow night whether or not they’re stuck together.
They’ll both be going into the bin if they fail the test. I hope this doesn’t discourage anyone of you from giving it a go. Give it a try you have nothing to lose, but knowledge to gain.