Compression fx? Boo-ERC r/d

[Brooklynbrew1]

Need to fix? Or, ok to leave alone? Thanks

[Del the cat]

I think a bamboo back will always overpower an ERC belly (though to be honest I've not used ERC).
Compression fractures like that can't be "fixed" the can be rasped out and patched or bound with fine linen thread (soaked in CA) for support. But the problem may just come back unless the tiller is good and the choice of woods is good.
They are not fatal to a bow, but it will loose power and take set.
Del

[Brooklynbrew1]

Thanks for your comment Del. It’s right next to a pin knot I tried to remove safely and bamboo node on back is offset ~1 cm. Perhaps I’ll watch it and see if others develop before patching or wrap.

[Pat B]

A compression fracture like that is a fatal flaw. It can be removed and replaced but it could repeat itself, like Dell suggested. I also think boo is too strong as a backing for ERC. Hickory, maple, elm or sinew would be a better option. If you are thinking of continuing on with this bow as it is be sure to wear a crash helmet and athletic cup.

[bjrogg]

A compression fracture like that is a fatal flaw. It can be removed and replaced but it could repeat itself, like Dell suggested. I also think boo is too strong as a backing for ERC. Hickory, maple, elm or sinew would be a better option. If you are thinking of continuing on with this bow as it is be sure to wear a crash helmet and athletic cup.

I have never done a ERC but I have seen some pictures of backed ones that blew up. Limbs stuck in the ceiling.

I always think of juniper as that girl my mom warned me about in high school. Pretty, smells good, fast and can break your heart in a second.

Bjrogg

[Brooklynbrew1]

I really appreciate all your comments. So, you think it’s more likely to explode? Or, just take set and lose performance over time? Either way I’m bummed. It’s a beautiful bow that I want to continue to shoot. With this in mind though, I won’t let anyone else shoot it.  I also don’t want to wear a helmet or jock strap. My football days are over

[sleek]

If you want, you might be able to save it by shaving the belly to a flat surface and glue on a new belly lam, one made of a more appropriate wood like hickory for example, and retiller it.

[Hamish]

 I'm betting that pin knot runs right across the width, just under the surface, on the right hand side?

If so, that was always going to be a point of weakness, not matter what type of wood you used for the belly.

+1 for Sleek's suggestion if you want to save it. Localized patches can work, but most of the time they start to lift if not done properly, or the incorrect glue is used.

[mmattockx]

I'll be a heretic and say you can back ERC with bamboo, but you would need to trap the back heavily to reduce the width of the bamboo and you would want to keep the belly dead flat and not round the corners very much to minimize belly stresses. It wouldn't be ideal, but you could do it. I agree with the others suggesting that hickory or maple are much better choices for backing ERC, but they don't look as nice as the bamboo.


Mark

[WhistlingBadger]

I always think of juniper as that girl my mom warned me about in high school. Pretty, smells good, fast and can break your heart in a second.

Man, I felt that one in my SOUL, BJ!   

Brooklynbrew, bummer about the fracture.  That really is a beautiful bow.  In my limited experience with juniper (the Rocky Mountain variety around here), those lateral knots are a deal breaker.  If it were me, I wouldn't shoot that one anymore--I'm pretty serious into my archery, but I'm more serious about keeping all of my body parts attached.

[RyanY]

I don’t think this is so much related to the boo ERC combo but more so the grain in that one spot. Especially since you’re not saying there’s fractures all over. Some people will do a patch fix for things like this. I’d probably shoot it for a while more and see if it gets worse or if others show up. I doubt it’ll daily catastrophically, especially since it’s backed.

[bjrogg]

Thomas . My mom might have warned me about them, but the attraction was strong. I do love the smell and colors of juniper.

So far I have only used it in my built up handles. It sure does have a draw to it though

And when it works it is a thing of beauty.

Bjrogg

[Brooklynbrew1]

Thanks for all your comments and advice!! This forum is such a great resource for novice bow builders like me. I think "hope" the single compression is due to the adjacent pin knot remnant (like Hamish said). So, I'm considering doing a patch like I read in Dean Torges' The Boyers Edge. But first I'd like to see if any other frets develop. I have a split off the original stave I can use for the patch. Here are a couple pics of profile and at brace. Don't have a full draw handy, I'll add when I get to it.

[mmattockx]

I don’t think this is so much related to the boo ERC combo but more so the grain in that one spot.

I agree with that, just didn't want anyone thinking there was something inherently wrong with the combination as long as the relative stiffnesses of the two materials are managed correctly.


Mark

[superdav95]

I don’t think this is so much related to the boo ERC combo but more so the grain in that one spot. Especially since you’re not saying there’s fractures all over. Some people will do a patch fix for things like this. I’d probably shoot it for a while more and see if it gets worse or if others show up. I doubt it’ll daily catastrophically, especially since it’s backed.

+1 on this.

 I’ve got a few of my first boo backed bows that had small stress compression that still shoot fine.  In my case I chocked it up to the boo backing being too thick for the core belly wood.  It’s very easy to go too thick on the boo backing.