Hide glue strengths

[pops1]

I thought hide glue besides the fact that it will come apart, was chosen because it is brittle when it dries therefore transmitting sound better than the other glues.

[fscotte]

Has anyone tried to break apart pieces of test wood with your hands? I was able to break apart a joint of 1/2" MDF with my hands. Not sure if an MDF joint would be weaker with hide glue than wood, but nonetheless it broke.

[dwhite]

I went to my local 'finishes' supplier today and bought some hide glue. I asked about glue strength as I thought I remembered reading about it somewheres. They phoned the manufacturer and told me that the hide glue had a "bloom gel factor" of between 130 and 140 grams at 12.5% concentration. Is this ok for instrument use. I'm looking to repair a very small crack that has appeared in the maple back of my IV kit and also to mix with some Lycopodium power kindly sent me by another forum member. I'm not sure if I'd be confident to use it for actual assembly as I haven't used hide glue for decades. All the hide glue I have seen does not mention glue strength.

What does 12.5% mean? Are they talking about weight? I've been mixing 50/50 by volume because I read that somewhere on the web and the working time is in seconds, a real pain. That using 315 glue. The lightest glue I can find is 222. If I could get a working time of a minute or more, I would be delighted. Just getting started here! Thanks for any advice!

[Michael Lewis]

If you keep temperatures above 80F (27C) your working time should not be a problem. In Martin's hide glue days their glue/assembly room was kept near 90F (32C) summer and winter. Just warming your parts will help considerably, but keeping the total environment warm is a sure thing. Hide glue will not gel at 90F (32C).