Backing for Tri-laminate ELB

[Redhawke]

I am building a tri-laminate English Warbow that will be around 80", draw between 100-120lbs at 32" draw. I have Ipe for core and Yellowheart for the belly wood. What would be the best backing material for this bow ? I have been thinking Hickory but can't seem to find a piece that is quartsawn so am leaning toward Hard Maple now but really unsure. Idea and suggestions are most welcome and appreciated.

[peacefullymadewarbows]

My experience is with hickory and bamboo. If you can get your hands on hickory I would as those are stiff belly woods that hickory can for sure handle. If you can get bamboo that would also be excellent. But I've heard well of hard maple as a backing and it's a similar density to hickory so that should work just be very picky with grain. Hopefully someone with more backing experience speaks up.

[Redhawke]

I finally gave up on the quartersawn hickory. I can't find a source that has anything 80". I did find a place that sells bamboo planks and have 6 of those on the way so the backing issue is solved I hope.
Thanks for the help peacefullymadewarbows.

[peacefullymadewarbows]

No problem. Do the bamboo planks have the crown from the outside of the plant intact? The nodes of bamboo are like knots in a stave and should be left proud.

[Redhawke]

They are supposed to but should arrive tomorrow so I can take a look then and let you know. I'm still trying to wrap my head around tapering the laminates so they all end together after reduction on the end. WoW.

[peacefullymadewarbows]

Yeah that can be intimidating. I tend to only taper the center lam. I leave the back and belly parallel. The belly tapers naturally during tillering. But I also don't glue in reflex. I've seen people taper lams and almost pre tiller them so the reflex glues in a nice shape. I made a tapering jig just by sawing a gentle straight line slant on a piece of 4x4. I send them through the planer. I had did a 1/4" center 1/8" tip ratio for my core and it turned out perfect at the tips in terms of having everybody in the horn tip.

[Redhawke]

Yes, the bamboo arrived with the nodes intact and looking great. Each plank is almost 1/2" thick so I'm guessing I will need to thin that down considerably. On the core of Ipe do I taper both faces or just the face that will be facing the belly ?

[peacefullymadewarbows]

Sounds like you got great boo. I just taper one face. Just make sure you have good even clamping pressure so you don't have glue gaps and you should be golden.

[Pat B]

IMO, I think you would be better served to use the ipe for the belly and the yellow heart for the core. Ipe is very strong in compression. I know the color combo would probably look better with the darker wood as the core but I'd be more interested in performance than beauty...not that it would be not beautiful either way.

[Redhawke]

Pat B, I actually intend to stain the Bamboo with brown leather dye which will give it a reddish cast. Yes, dealing with these beautiful exotic hardwoods I have to remind myself it's not an art project the performance should in fact come first. My original plan was to use the Ipe as the belly wood but I only see it used as a core wood on tri-laminates so far. I thought the color scheme would be dramatic to the eye so that option remains on the table. I have been thinking about the bamboo a bit and would like to know what a good nominal thickness would be for that layer. It's coming in at around 1/2" at the end of the planks. I'm a bit worried that it's too thick but can't find a reference anywhere for the poundage I'm attempting to obtain at end of build.

[Del the cat]

IMO, I think you would be better served to use the ipe for the belly and the yellow heart for the core. Ipe is very strong in compression. I know the color combo would probably look better with the darker wood as the core but I'd be more interested in performance than beauty...not that it would be not beautiful either way.

+1
The core does less work than the back or belly, so it wants to just be stable and light.
The middle lamb should be tapered, but just taper one face... the angle is so slight it's not worth trying to taper bathe faces. At the centre where the two tapers meet it will give a V slight  raised pint, this can just be sanded to flatten it or blend it to a gentle even curve so the belly lam will glue down well.
Del

[DC]

Bamboo backing is very thin. Approximately 1/8" in the handle and tapering to 1/16" at the tips. If you are making a wide bow it may be thicker depending on the original diameter of the bamboo log.

[Marc St Louis]

I like Yellowheart but I would use the Ipe for the belly as well.  For an 80" bow pulling over 100# I would use a Bamboo backing a bit thicker than 1/8" thick.  Quite frankly I would make the bow somewhat shorter than 80", unless you are making a bow that will pull well over 32" of draw.  I also find that Maple is a better backing material than Hickory

[Redhawke]

I like Yellowheart but I would use the Ipe for the belly as well.  For an 80" bow pulling over 100# I would use a Bamboo backing a bit thicker than 1/8" thick.  Quite frankly I would make the bow somewhat shorter than 80", unless you are making a bow that will pull well over 32" of draw.  I also find that Maple is a better backing material than Hickory

Marc St Louis the young man this bow is intended for has a 32" draw to his anchor point. My  thinking has been that the longer bow would make the (for me at least) high draw weight easier to for him to handle, he is 6'2" tall. How long for the given draw weight and his height do you think would be appropriate ?

[Marc St Louis]

Personally I would go with a bow around 75" in length