Replies

1. 
   RickW | Aug 08, 2008 03:07am | #1

   I can't answer the first part of your question, but in response to the second part, alcohol will crystallize hardened hide glue.
   Rick W

2. 
   AdamCherubini | Aug 08, 2008 03:25am | #2

   The number is strength related. I think it's molecular weight or some such. I don't think it matters too much which number you choose. Know that higher strength glues have shorter gel times. So the two are related I think if you stay between 135 (which I think is the lowest available) and 192 or so, you should be fine.

   You can use liquid hide glue as an additive to reduce stiffness and increase gel time. This also weakens the glue. If you plan to use liquid glue to slow down hot hide glue, choose the higher strength glues.

   Adam

1. 
   SteveSchoene | Aug 08, 2008 03:54pm | #4

   Have you tried Old Brown Glue?  It's Patrick Edwards' version of liquid hide glue.  http://www.wpatrickedwards.com/gluepage.htm   Urea is an additive for extending the working time--probably also used in the commercial liquid hide glue.  I haven't used Mr. Edwards glue yet, and it is no surprise that Patrick speaks highly of it, so I was looking for a third party opinion. 

   It is interesting to note that even the Titebond liquid, which is less strong than hot hide glue, is just as strong as PVA glues.  The implication is that hot hide glue is stronger than the standard run of wood glues.  It also shrinks as it cures, part of the reason it can be used on "rubbed" joints without clamping, partuclarly useful for attaching glue blocks. 

1. 
   AdamCherubini | Aug 08, 2008 04:16pm | #5

   I've not and for no good reason except that i have a glue pot and I'm happy with it. Hey, I'm going to get to meet him next year and I'm really looking forward to it. I think he's really neat.Adam

2. 
   dkellernc | Aug 08, 2008 04:52pm | #6

   Adam - If I remember correctly, the "gram strength" rating of hide glue is a measure of the solids content remaining after the liquid from the extraction process is evaporated (presumably measured as "grams per gallon" or some other liquid measure).  Bones, hides, and cartlidge is put in very hot water, stirred around and allowed to steep for a while, and the liquid is poured off.  The liquid is dried (or more accurately, the gel that results when the liquid is cooled is dehydrated), and fractured into a coarse powder. 

   The hides/bones/cartlidge is then re-soaked, and the process repeated.  The strongest gram strength glue is the result of the first extraction, and lower gram strength glues the result of later extractions.

   I've made fish glue before with the skins and bones of filleted bluefish caught at the beach - it really works, and is a pretty neat process.

1. 
   SteveSchoene | Aug 09, 2008 03:39am | #7

   For what it is worth, gram strength or jelly strength is a measure of how much weight in grams is required to depress a ½ inch diameter plunger 4 millimeters into the surface of a gelled sample of a 12.5% solution of hide glue at 10 degrees Centigrade, according to some tech info from Milligan and Higgins at this url: http://mfds.org/thetechnicalsideofanimalhideglue.aspx 

1. 
   dkellernc | Aug 10, 2008 05:49pm | #8

   Thanks for the link, Steve.  The info I cited above was clearly only partially correct - a good example of not trusting everything you read just because it's in print.  I can only assume the author was interpreting and repeating what he was told by someone not familiar with the original standards. 

   One interesting thing about the link was the statement of the use of an alkaline extractant (in this case, Calcium hydroxide).  Since alkaline compounds break down proteins by hydrolysis of the peptide bonds, I wonder if the key component here is the divalent calcium ions (in other words, attempting this with sodium hydroxide would not work).

   Oddly enough, the fish glue I prepared worked pretty well as just an extract of the fish skins and bones with very hot water.  It was really tacky, and bonded a couple of pieces of wood together pretty strongly after I let it dry for 24 hours.  I wonder whether it would have worked even better if I'd used lime or slaked lime in the hot water (it did smell strongly of fish, BTW - too strongly for me to want to really use it for a useful purpose).

3. 
   Rich14 | Aug 08, 2008 03:59am | #3

   Steve,

   There's lots of hide glue info on the Net.

   Here's one link:

   http://deller.com/newpage8.htm

   Search on the page for "gram strength."

   Rich

4. 
   SawdustSteve | Aug 10, 2008 11:40pm | #9

   Thank you all for comming to my aid. I KNOW I can depend on you guys and gals to get me lead me to the correct information. Special thanks to Rick W. for the info that alcohol will crystalize hide glue. I've printed out this whole thread and the links to do some more research.
   SawdustSteve