I’ve always wondered how much of a kangaroo skin isn’t used in the whip that I bought it for. For example when you buy a skin you have to trim the edges to give it smooth edges to cut around, so that’s a bunch of waste there. Then there are sometimes undesirable parts, or sharp turns that you need to make easier to cut around. Then there’s all the waste from cutting, paring, splitting, and from over-cutting the strand length.
Here are my notes from the kangaroo skin I used for an 8 foot bullwhip:
Since this whip isn’t finished yet, these are completely final numbers. Also keep in mind I’m measuring with my kitchen scale, so it may or may not be 100% accurate. Also be sure to consider this waste is by weight, not actual area. For example my initial trim of the skin will be trimming off some of the heavier parts of the skin, so it may have more weight, but not the same area as other places on the skin.
The skin I bought was a heavy kangaroo skin from David Morgan and was 71 dm2 and weighed 650 grams when I got it. After the initial trim I cut off 67 grams leaving me with a skin that weighed 583 grams. Right away the initial trim I have about 10% of the skin that’s not usable. That was an amazing revelation to me, I figured I’d have 10-15% waste total after everything was cut off. The initial trim put me at the lower end of my estimate, so my guess is going to be way off!
After cutting out the first belly the skin weighed 490 grams and the belly was 66 grams. Then the belly after all the strand prep and cutting off the over cut strand after the belly was plaited weight 33 grams, or 5% of the belly’s weight!
The second belly was 119 grams and generated only 14 grams of waste during the strand prep and the skin weighed 364 grams after the belly was cut off. I think this layer had the least waste because so much of the stretchy part had already been cut off the skin and sharp corners were rounded.
The overlay weighed 291 grams and 274 grams after the strand prep. I’m going to create some more waste before the whip is finished from the over cut strands, but many of them will be repurposed back into the whip as knots or a wrist loop.
For this particular whip I used:
33 grams for the inner belly
105 grams for the outer belly
274 grams for the overlay (transition knot and wristloop)
412 grams total of kangaroo skin that went into the whip from a skin that started at 650 grams. So just under 2/3 of the skin went into the whip and I had a center of the skin leftover that was 73 grams, but I’ll still need to cut the heel knot of of it.
What does all of that mean? I don’t know, but it’s been something I’ve been curious about for a long, long time!