Primitive Archer

Main Discussion Area => Bows => Topic started by: Mafort on April 25, 2019, 06:37:01 pm

Title: Tri lam elb question
Post by: Mafort on April 25, 2019, 06:37:01 pm
I was looking around on 3 rivers archery today and was wondering if I wanted to do an Osage orange belly with a hickory core and bamboo back. My question is do I have to splice the Osage together because they come on board form or can I simply butt the Osage together and glue the hickory and then the bamboo. I’m probably going to catch flak for this question but I figured I’d ask before I wasted time and resources. Also what about the kind of glue? What is the best to use with a tri lan.
Title: Re: Tri lam elb question
Post by: Pat B on April 25, 2019, 07:39:24 pm
The wood combo will be a good one. If you buy the lams full length(72") or 2 half lengths(36") will matter. If it is 2 pieces for the core and/or belly you can use a scarf joint where both piece are tapered on one end to fit together. Stagger the joints between the core and belly and use a riser overlay(underlay). A scarf joint would give you more shear strength than a butt joint.
 You can use TBIII or Unibond or Weldwood Plastic Resin, or many others. I'm sure you'll get other glue options.
Title: Re: Tri lam elb question
Post by: Del the cat on April 26, 2019, 12:31:58 am
Like Pat says, or I use a short Z splice on belly lams and the glue a thin riser/grip section over the join.
A short Z is very much easier than a long one.
I wouldn't trust a butt joint, although theoretically its fine, there is very little glue area and the shock/vibration of loosing may cause it to crack.
I'm actually working on one now, continuous boo back. Yew core with short Z splice. Ipe belly, with a 3" section in the middle joined to the 2 end pieces with scarf joints (yes, my Ipe was just some off-cuts that weren't quite long enough  ::) ;D ) and a thin grip/riser lam over the centre where the scarf joints are.
Del
Title: Re: Tri lam elb question
Post by: Mafort on April 26, 2019, 02:10:52 am
The wood combo will be a good one. If you buy the lams full length(72") or 2 half lengths(36") will matter. If it is 2 pieces for the core and/or belly you can use a scarf joint where both piece are tapered on one end to fit together. Stagger the joints between the core and belly and use a riser overlay(underlay). A scarf joint would give you more shear strength than a butt joint.
 You can use TBIII or Unibond or Weldwood Plastic Resin, or many others. I'm sure you'll get other glue options.

The core and back are full length the Osage would be 2 36” sections
Title: Re: Tri lam elb question
Post by: Dances with squirrels on April 26, 2019, 03:06:17 am
Even though the other two pieces are full length and you may be adding an additional handle piece over the osage joint, I'd use a Z-splice or scarf joint that is almost as long as the handle. My handles are 4" and joints 3 3/4", so the leather covers the joint.

I'd glue the osage together first, let it cure, then do a second glue up where the three full length lams are assembled. I use Smooth On epoxy.
Title: Re: Tri lam elb question
Post by: Mafort on April 26, 2019, 03:15:04 am
Can you send me a link to that epoxy?
Title: Re: Tri lam elb question
Post by: Ryan Jacob on April 26, 2019, 04:05:19 am
I recall someone suggesting that before when I was lurking around here. But why tempt fate? 2, 36” long pieces is a lot to work with and gives you a good amount of wiggle room. It just the safer option, more time consuming, but safer to splice.
Title: Re: Tri lam elb question
Post by: bassman on April 26, 2019, 08:34:03 am
A five inch v splice will work too ,with Smooth On.