Author Topic: hide glue for the belly?  (Read 107 times)

0 Members and 1 Guest are viewing this topic.

Offline joachimM

  • Member
  • Posts: 563
  • Good - better - broken
hide glue for the belly?
« on: November 14, 2017, 11:40:56 am »
Gelatine is nothing more than pure-grade hide glue, sold in translucent sheets. Which are very bendable. When hide glue has cooled, it becomes a pretty bouncy gelly. I guess when dry it may also take compression well.
Since we use hide glue for backing fibers (sinew, flax, sisal, ...), could we use it for a belly too?

After all, that's what's being done in GF bows, but with GF and epoxy/resin. I'm not sure how good GF is itself in compression (after all, a glass marble rebounds pretty well), but I've read that it's mostly the epoxy matrix taking the compression.

Anyhow, could we make a decent composite natural material for both backing and "bellying"? On the back the fibers would take the tension, being held together by the hide glue, on the belly the dry hide glue would take the compression, but being held together by the fibers. 

Surely, someone has tried this already, no?
Tillering is easy. Problems arise when a bowyer thinks he's right and the wood is wrong.

Offline Pat B

  • Administrator
  • Member
  • Posts: 30136
Re: hide glue for the belly?
« Reply #1 on: November 14, 2017, 12:36:03 pm »
I don't think that hide glue has good compression properties but I've never tried it so it is just a guess.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline DC

  • Member
  • Posts: 4769
Re: hide glue for the belly?
« Reply #2 on: November 14, 2017, 01:56:01 pm »
I've wondered about this. The little cubes of dried glue seem pretty tough. Wait a second.-------
I just went out to the shop and squeezed a piece in the vice. It was seeming pretty solid and then shattered. I'm not sure what that means. Maybe a guy should make up a small sample. It would take a lot of coats of glue.
Vancouver Island

Offline joachimM

  • Member
  • Posts: 563
  • Good - better - broken
Re: hide glue for the belly?
« Reply #3 on: November 14, 2017, 10:28:45 pm »
I've wondered about this. The little cubes of dried glue seem pretty tough. Wait a second.-------
I just went out to the shop and squeezed a piece in the vice. It was seeming pretty solid and then shattered.

Glass in a vice will shatter too, but marbles show that glass is very good in compression. 
It would have to be put in a fiber matrix, just like glassfiber in lams is embedded in epoxy resin.

The question is probably: why bother if you have better/easier materials to work with that also give you excellent bows...
Tillering is easy. Problems arise when a bowyer thinks he's right and the wood is wrong.