Yucca backed osage molle

[Mo_coon-catcher]

I finally tried my hand at a yucca fiber backing. I will say that it seems to work. Though I don't have enough arrows through the bow to tell how well it will last. I will say though that for the amount of work involved with laying down the fibers I would rather go with sinew for performance gains. But the yucca is more easily available and easier to process. Buts it's holding and between the heat treating and fibers the strength did increase. I'll probably try it again, but apply it green gluing down with hide glue and see of Itll pull some reflex when it shrinks as it dries.

It's an osage mollegabet, heat treated and yucca backed, that came out 30# @ 27". Starting with 3/4" reflex, 1/2" deflex after shooting, and flat after resting. Not too bad for taking 30 minutes making brace tiller, and another 30 minutes getting it shooting after realizing it was so far under weight. I know the tillers not perfect, but I didn't want to lose any more weight and it shoots well enough as is. But please point out anything that's off about it. I split out the stave in November from a fence post in assuming was cut in September/October, and carved out the bow about three weeks ago. So I rushed it a little. Sorry about the lack of pictures. I'll put up more once I get it fully shot in and finish put on. It's still naked so don't want to show I off too much.

 It came out under weight after fighting with some cracks. I tried leaving one ring of sapwood for the back but due to time restraints the wood wasn't dry yet. So lots of drying checks. I went for a rounded belly to try relieving some strain from the back but once I tried going to full brace and what would have been about a 50# pull. I got one limb bending well and the other a little strong. I scraped the strong limb and it didn't move. Did it again and the same thing. After the third time it looked to be going backwards so I checked over the bow again. And more cracks opened up on the back weakening the limb and making the outer limb bend more than I eanted. Before I realized what was making it weaken I had already unnecessarily scraped a bunch of wood off. I learned a few things from this bow. Dont go for a sapwood back on osage when the wood is still green, it will crack. Watch for checks forming on the back after a sudden shift in tiller. Don't scrape to correct when said shift happens. Yucca makes a reasonable backing with being a radily available material. And it's possible to take light draw osage from braced to shooting in 30 minutes.

Thanks for looking. More pics will come in a day or three. Feel free to criticize as you please. I like to know where I went wrong so I can correct it later and others can learn. More pics will come once she's fully dressed up, only wanted to give a tease while she's still naked.

Kyle

[E. Jensen]

Awesome idea!  Pic of the back?

[BowEd]

Yea bud that sapwood is suseptible to crackng when air dried too fast.Now you know.I'm sure it shoots nice for ya though.Nice bow.
A few years ago I backed a KCT bow with 12 ply linen string.Was'nt on the forum at that time so I did'nt take pics but it gained I figured about 1# per 3 or 4 strands of string.Total of 28 strands.So it gained about 7 or 8 pounds.Applied it on with smooth on epoxy.Makes the bow almost indestructable.Yours too I imagine.To top it off I put about a 1/16" of horn on the belly too and it gained another 8 to 10 pounds.

[willie]

what glue did you use for the yucca? If it is readily available, why not keep putting it on? If the belly side is good, the cracks might not matter too much if they were further towards the middle of the bow.

[joachimM]

Looks fine to me!
If you want to up the poundage, why not add more backing? I guess you can raise it to 40#.

[Springbuck]

Looks good, looks fun.  Did you process the yucca yourself?

Also, I know how sinew is used, and I have used plant fiber backings.  There are ways to use them to boost performance, but usually if the stave was sub-standard to begin with.

[BowEd]

The way to help bring poundage up on a bow can be done may ways.The thing about fiber backing is that it will stretch or take set with no return.Once stretched it does not spring back.Even using hide glue won't help that much.Adding extra poundage to your bow can be increased even more somewhat by reverse stringing your bow while glueing the fiber on.

[PEARL DRUMS]

Snip a few inches off the ends Kyle. I don't know the length you have, but the pic tells the story. Tiller looks nice for a wavy one.

[Mo_coon-catcher]

The yucca was processed myself from my moms plants using a rock to pound them and a chuck of steel to scrape away the extras. I let the yucca dry for a couple days then I washed it to re moisten it before applying. Those plants are starting to take over the yard. So if anyone wants to try some themselves, let me know. I used TB2 since I managed to misplace the TB3 and I didn't have a heat source handy to use hide glue. I think I will put some more yucca on and clip the tips an inch each and see what happens. Think I should apply this next layer with the bow reflexed  a little to see if that help or leave it straight to reduce some stress since I'll already be stressing it more by clipping it?

Kyle

[PEARL DRUMS]

Kyle Ill gladly take some of the bigger 1 inch round or larger stalks off your hands. Nothing better than yucca for friction fire spindle. IMO.

[Mo_coon-catcher]

That shouldn't be any problem. That's about how large the stalks of these plants get and about 6' tall. I'm not sure if there are any still up. But I'll see if there is when I get home. If not they'll be back this summer.

Kyle

[aaron]

Awesome project, thanks for sharing. On the idea of using it green in hopes to gain some reflex through shrinkage, I am not sure that would work. I think the fibres would shrink alot in diameter, but not in length. This shrinking of diameter might mess with the integrity of the fibre/glue matrix. When we make baskets , we dry the material for a year, then rehydrate by soaking for a day. When the material rehydrates, it does not regain its original diameter, so when the basket dries, the weave remains tight. When you make a basket of green material, it shrinks and becomes loose. The same is true for cordage. If you do test out this method, you may want to do a small tester piece first and please post results if you do.

[BowEd]

Your bow is reinforced very well with your yucca on the back.Reflexing it 4 to 5 inches won't break it when rebracing and shooting it.Even after piking it.Bet in the end after piking it and reflexing it you might be pleasantly surprised to be in the mid 40's or so in poundage.Not much to retiller either if applied on both limbs evenly.

[Mo_coon-catcher]

I got some more yucca scraped clean yesterday after putting down some sinew on one of my trade bows. There should be enough to put down a good heavy layer. I'm going to give it a few days to dry out before I put it on. Sorry pearl drums, but there wasn't any stalks left on te plants. I'll remember ya when they grow back this summer. Once I get this now all dinished I'll post some more pictures of it.

Kyle

[DC]

Is it just the stalks you use or are the fibers in the leaves any good? We have two yucca plants so we get two stalks a year. A good year, yucca is iffy for blooms up here.