Primitive Archer
Main Discussion Area => Bows => Topic started by: stonecarver on October 30, 2016, 06:10:46 pm
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I made knox glue for my first rawhide backing, before doing so I did quite a bit of reading about bone, hide, sinew, and connective tissue glues. But I find I am still a little unsure about it, here is what I have done.
While making jerky out of a couple venison hind quarters I put all the sinew and jointed the bones and some meat scraps into a pot to boil for my dog. I was saving the sinew, but wife did not know and added it to the pot.
From my reading I believe I can remove the jell from the fat and water and that it would be a glue.
My questions are:
1) Is this in fact glue?
2) would this be a good glue, as in better than knox, or would it be a weaker glue?
3) If it in fact a good usable glue how can it be stored for long term use?
Thanks!
SC
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The gel is the glue. Knox is food grade and refined. TBBI said Knox is stronger but glue made from rawhide scraps and sinew is plenty adequate for sinew backing, rawhide backing and snake skin backing.
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I save all my sinew scraps amd make glue from that. It works great for sinew backing. I have mixed Knox with it to.
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I make my own glue as well, just remember, boiling sinew or hide makes weaker glue, you want it hit enough to shrivel the sinew, but don't boil it. I think around 170 degrees
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aye. A horn bowyer I know likes to keep it around 150-160F; according to him, the literature says that preserves long strands of collagen. just have to keep it for around 24 hours. He makes croaker bladder and sinew glue.
I find it hard to believe that sinew glue cooked at these temps would be weaker than knox. I think he said sinew is stronger than fish but the gelling time is worse or something. But hey, I would strongly appreciate any proof that knox is stronger. that way I don't have to kill myself trying to find sinew or croaker bladder to make glue (I need strong glue)
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https://en.wikipedia.org/wiki/Gelatin
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Any branded gelatin isn't as strong as making it yourself...as long as you do it correctly! As Wizard says low temperature is absolutely key. Your dog food would work as glue but next time do a proper 'cook' and keep a constant eye on the temperature as higher temps degrade the collagen.
The difference between sinew / hide / fish bladder glue is pretty much just the gelling times. Fish slowest, sinew medium , hide fastest gelling times.
The fish glue aslo resists moisture better than the others.
The bladders you want are from a fish called yellow croaker - quite easy to get if you go to your local China town. Just expect some funny looks until you hit upon the right stuff! The soup made from the bladders is very good for you too...almost pure collagen....keeps those joints supple.
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So cooking glue at the correct temp is vital for getting the strongest glue. Check
mikekeswick-
While searching the yellow croaker bladders, first I found them to be quite pricey. Second thing I found was my son and I hooked a bunch of fish we could not identify. Looking at the croakers at California Marine Sports Fish Identification, I learned they were White Seabass which is of the croaker family.
Range: White seabass occur from Magdalena Bay, Baja California, to Juneau, Alaska. They usually travel in schools over rocky bottoms and in and out of kelp beds.
https://www.wildlife.ca.gov/Fishing/Ocean/Fish-ID/Sportfish/Croakers - it's a state game website, I hope the link is ok.
We caught them trolling for salmon about 50 miles from Ketchikan.
I wonder if rockfish bladders would work, we get some huge yellow eye rockfish, that have large air bladders. We usually catch some every summer, great fish and chips.
I also read that fish or sinew / rawhide glue can be dried for storage.
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I have dried home made hide/sinew glue for longterm storage. The best way to do it is in small batches. Warm and thin the glue until it runs like thin syrup. Pour it onto any flat surface that will hold it, such as cookie sheets, plates, SilPat baking sheets. Pour only enough that it does not cover the entire surface so that it can spread itself as thin as it is able. Let it gel as it cools. Allow it to dry until you can peel it up as a sheet.
Now place those rubbery thin sheets on racks or wire mesh (I have used old screen windows propped on blocks to allow air flow in, around, under, etc) and place a fan in the room to move the air. You know they are thin enough that once they have dried for 24 hours, you can crumbled them in your hands like potato chips. Crush it up and leave exposed to moving air for another 24 hours at least. Then store in plastic tubs in the freezer.
If you think you are going to skip the step of removing the thin rubbery sheets from the cookie sheets/whatever, you are an idiot. I ruined two BRAND NEW GLASS BAKING DISHES doing this. The hide glue will mechanically bond to microscopic pitting in the surface of the glass and as it shrinks, it will literally knap flakes of glass off as it contracts!!! It will peel up the nonstick coating of cookie sheets, and destroy the glaze on crockery and pottery! And that, kiddies, is why it works so bloody danged good on wood and sinew....it has even more porosity, and consequently even better mechanical adhesion.
The best I have found are the SilPat cookie sheets. I dropped $30 on a silicone baking sheet and NOTHING sticks to it, not even burnt on fake cheese from crappy frozen pizza!
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Don't dry it on aluminum foil either!
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JW_Halverson- Thanks for the tips, I had to read your post to the wife. I will dry the gel, on a drying screen that is by the ceiling near my wood stove. Ouch on the glass dishes!
osage outlaw- Thanks! Got you, no aluminum!
I have 5 chunks of 12 to 15 inches long moose front leg sinew and starting to plan my first sinew backed bow, I did a rawhide backing on a little yew limb bow I am playing with. The sap on the back of the little yew had a couple bad spots from rubbing other branches, so I rawhide backed it using knox glue, an ace bandage, and heat gun. Glad I did the rawhide backing as it was a learning experience.
Looking at TBB one on sinew backing and searching the internet, and planing a Sitka Alder short bow.
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This might help you out. It's a post where I made my first batch of glue with several pictures. I got a lot of good advice. When I dried the little pieces on aluminum foil some of them stuck to it. I had to scrape the foil off of them.
http://www.primitivearcher.com/smf/index.php?topic=30740.0
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Silicone baking trays are perfect for drying it on. I haven't found anything better, non stick , flexible and tough :)
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Not sure if I am spelling it right but isinglass which is used as a beer and wine purifier is made from fish bladders and makes an excellent glue. You can buy it at any brewer supply store.
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JW i had the same ideas for storage as you but i used ice cube trays and it worked well, i also just poured some in a butter tub and froze it, then i just microwave it in increments till it gets thawed and the proper temp as it cools i just nuke it some more
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JW i had the same ideas for storage as you but i used ice cube trays and it worked well, i also just poured some in a butter tub and froze it, then i just microwave it in increments till it gets thawed and the proper temp as it cools i just nuke it some more
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