BBI Brake

[clemson2fan]

I recently built a bamboo backed ipe. I used the build along from Sam's site. Everything went good so I thought. I was shooting it when the bamboo cracked on a node and split down itself. Could anyone please shed some light on what went wrong. Where I could improve. The bamboo I used was some I harvested.

Also, does bamboo have more of a smell when it's not fully dry? Maybe the bamboo I used was still to wet, however, it didn't seem to wet, just smells awful. I'll provide a link to photo bucket for the pictures of the break.

   Photos

[Roy from Pa]

Looks like you may have sanded the nodes down too much and got them too thin. All I do is barely sand off the jagged edge that sticks up. All the boo I've ever used did not really have an odor so maybe yours was too wet. Do you have a moisture meter? Around 10 to 12% is good for boo. Maybe it was the type of boo that you used, I always use Moso.

You could sand that entire piece of boo off and glue on another one to save the belly wood. It's a bit of a pain but it's not too bad of a deal to do it.

[clemson2fan]

Thanks for the quick response. Yes I did sand the nodes and probably took to much off. I did sand them by hand and tried to sand lightly to avoid this.

That was my next question about sanding off the boo and gluing a new piece on. Is there anything that I should know before attempting this?

Unfortunately I don't have a moisture meter, so I have no way of telling the moisture content. I was thinking that the odor was from the bamboo maybe being to moist still? When I harvested this I also took some pieces that had already died and dried. These pieces didn't have any odor but had mold on them and someone told me that the mold would cause a failure.

[macbow]

Interesting break.  I'd agree it was probably too moist.
When I get my bamboo slats that appear to be very dry I still put them in a dry box at about 100 degrees and with a low fan moving air to dry them more.
There are a few guys on here that harvest their own bamboo and could give some input.

Taking the old bamboo off should work.

[Roy from Pa]

When sanding off the boo, only sand it till you see the glue joint starting to appear, then move on down the limb. After it's all sanded off, go back with sand paper to smooth up the glue joint. I go back with a toothing plane blade and just level it up and that also gives the wood the needed grooves for a better glue joint. Just be careful not to sand into the belly wood along the edges.

[Eric Krewson]

Bad bamboo will break like yours did, never had bamboo that smelled bad so that could be an indicator. Unfortunately, there is no way to tell if you got a piece of bad bamboo until it fails.

I bought a 25 slat bundle of absolutely beautiful bamboo once, every bow I made from it had a bamboo failure, bad bamboo with no indicators, sure looked good to start with.

You did sand the nodes too far down which weakened them.

I sand off failed bamboo to about 1/16", don't see the glue line but have the bamboo ground off flat across the back. I like to leave a little of the original bamboo to glue to and use a toothing plane iron to rough it up like Roy does.

[clemson2fan]

Thanks for the insight everyone. Such a sad thing to happen after putting hours of work into it, then this.

I think I will let this bamboo sit in my shed for another month or so. Than if the smell goes away I'll try another piece of this boo. If not I'll just order some slats from somewhere.

This weekend I'll sand the boo off the broke one and see how it turns out. Question, after sanding and gluing a new one on I'll need to re tiller right? If this is the case won't I lose some pounds?

[Roy from Pa]

If you leave a 1/16th of boo on, like Eric suggests, you shouldn't lose any weight. You will need to recheck the tiller, but I wouldn't expect it to be very far off. I have never used boo that I had cut, but a month doesn't seem long enough to me for it to dry. Eric, how long does it take your boo to dry that you harvest?

[clemson2fan]

Eric has already gave me some great wisdom on harvesting and drying. However, this is a piece that has been in my shop for almost 9 months. I used his suggestions on my newly harvested pieces.

The smelly pieces didn't get the smell until I put in the sun for a couple of weeks trying to turn the color.

For my broke bow I'm gonna go ahead and order a slat from somewhere. Because I can't wait to shoot it again. I was really blown away how much faster it was than the board bows I've made.

[Roy from Pa]

Cool on Eric, he has played the boo game a long time.. Yup a BBI will smoke a board bow for sure:)

[Eric Krewson]

I knock the nodes out with a hoe handle, let the bamboo dry for a couple months in trunk form, cut and thin the slats and give the slats a week or so in my drying box before I use them on a bow.

Here are some of my flattened and thinned slats just waiting for me to be inspired enough to make bow out of them.

   

[Roy from Pa]

Sweet boo, Eric. I take it, knocking the nodes out kills the plant?

[clemson2fan]

Hey Eric, after the slats sit in your hot box for a week or so do they turn color, or lose the green color?

Is this something that you worry about?

[clemson2fan]

From my understanding he told me it's more about letting the air flow through. As to not let mold grow on it and it helps it dry faster.

[Eric Krewson]

Yep, the trunk dries much faster with nodes knocked out, you get a chimney effect. Th main reason I leave the trunk or clum whole is to keep it in it's normal shape. If you cut the slats green they have a tendency to cup up when they dry becoming U shaped and becoming unusable.

My bamboo stays light green even after drying, the tan color is under the rind and shows up when I sand the rind off.