Bamboo R/D from two planks only!

[Apex Predator]

Any of you folks make an all bamboo bow out of two planks?  I am intriged by the idea of an all bamboo bow glued into a R/D profile with using nothing for a middle lam.  I was thinking of a handle piece aproximately 10-12" long laminated between the boo planks.  My boo planks are a full 2" wide and will finish out around 1/4 thick after ripping them down to slightly less than 1" wide.  Could some of you folks share with me some dimensions to start.  Tillering will be difficult with raw boo on the belly.  I would be pleased with something in the 62-66" range drawing 50@27.  I think it would be easier to err on the lightweight and long side and just cut her down some to make weight if needed.  What you ya'll think?

[Dustybaer]

i've been toying around with the same idea for quite some time now, but haven't found the time to just try it.  i think it's doable, but have no clue what to expect draw weight wise.   here's how i was going to do it (plus a few things i seem to recall reading):  raw boo on the belly will take set.  you should exaggerate your reflex.  if you shorten an R/D, you're cutting of your reflex section, so it would be better to just accept the weight you get and start a new one with modified dimensions for more draw weight.  tiller each plank individually and then laminate them into the R/D form.  final tillering is best accomplished by removing material from the sides.  removing material from the belly is risking to cut thru the power fibres.  overall, it should result in a fairly fast bow.  oh, i almost forgot: a trapezoid crossection, since boo is stronger in tension then in compression.

disclaimer:  again these are just my thoughts and are not backed by any experience.

[Apex Predator]

Thanks Marius.  Pretty much what I was figuring as well.  I guess the time investment wouldn't be too massive.  I could probably have it glued up within a couple of hours, then I would know after drawing it whether to invest any more time in it. 

[Pat B]

Generally when using bamboo for a belly you would want to temper it to increase the compression strength. Except for pre-tillering before glue up, all of your adjustments will be from the sides of the bow. I have plans for a simple(?) D bow using boo back and belly. Maybe with a tapered lam at the center of the bow to build up the handle.
   Keep us informed of your progress.     Pat

[Apex Predator]

I think I will build a few more boo backed bows before tackling this one.  Thanks for the advice though.

[Pat B]

There was an article in one of the older PA magazines about tempering bamboo. Three different guys and 3 different approaches to tempering the boo. One even used a friends pizza oven, set at 400deg(F) to "cook" the boo. I'm sure someone here on PA will have an appropriate method of boo tempering.   Pat

[mullet]

  I've Tempered the belly using my heat gun on the low setting. I do it by using short up and down motions about 6" away from the boo working my way down the length. I leave it in one area until you start to see it sweat ,then move down to a new section. You have to be careful and not get it too hot or the boo will start checking while you watch. I found out the hard way. Hope this makes sense.