Trad Gang

Main Boards => The Bowyer's Bench => Topic started by: VTer on August 18, 2025, 11:21:27 AM

Title: Lam splicing glue?
Post by: VTer on August 18, 2025, 11:21:27 AM
I've been having problems splicing my bamboo lams together with star bond superglue. The problem happens on the lam on the back of my forward riser longbow from the arc on the back, no problems on the belly side. Has anyone used ea40 in a situation like this as I'm sure it has more flex too it than superglue?
Title: Re: Lam splicing glue?
Post by: kennym on August 18, 2025, 12:06:32 PM
Never tried EA40 but I make a long splice with CA.

I think Kirk the boat builder :)  said splice length 6x thickness so that's what I've been doing.

Apply glue to wet both parts and clamp for 15 minutes.

A slower setting CA glue is prob better too.
Title: Re: Lam splicing glue?
Post by: derekdiruz on August 20, 2025, 02:33:54 PM
Greg, one thought I had the other day, when you said you use just tapers:

Lets say you measure a .100 at 10". Why not make one taper .100" at 13" and the other .100 at 7" and move the splice 3" down the grip and off of the most extreme portion of curve?
Title: Re: Lam splicing glue?
Post by: Watsonjay on August 20, 2025, 09:37:47 PM
I had the same problem a few months ago when doing the bow swap challenge this last year with the same forward handle design. Two things worked for me:
1. After completing the taper and after gluing the joint I heated the bamboo and pressed it into the form and let cool.
2. I used 2 thinner lams instead of just 1 thicker lam

But what Kenny said does help too make the joint as long as you can helped me too and I use blue lid gorilla ca glue and let sit compressed overnight
Title: Re: Lam splicing glue?
Post by: Tim Finley on August 21, 2025, 12:17:47 PM
I use a fairly short splice and use gorilla wood glue never had a problem.
Title: Re: Lam splicing glue?
Post by: Kirkll on August 21, 2025, 12:37:03 PM
Quote from: VTer on August 18, 2025, 11:21:27 AMI've been having problems splicing my bamboo lams together with star bond superglue. The problem happens on the lam on the back of my forward riser longbow from the arc on the back, no problems on the belly side. Has anyone used ea40 in a situation like this as I'm sure it has more flex too it than superglue?

Are you having problems with the splice coming apart pushing it into a radius shape in the form? how thick are the lam's? 


 You could try thinning down the lam thickness. use two lams instead of one.   Kirk
Title: Re: Lam splicing glue?
Post by: VTer on September 03, 2025, 09:23:30 AM
Quote from: Kirkll on August 21, 2025, 12:37:03 PM
Quote from: VTer link=msg=3072297
/quote]

Are you having problems with the splice coming apart pushing it into a radius shape in the form? how thick are the lam's? 


 
Yes, pushing into the form is when it happens. About a .090 butt thickness. Taper is roughly 1/2" long
Title: Re: Lam splicing glue?
Post by: Kirkll on September 03, 2025, 12:38:13 PM
The only other thing i can think of besides thinning down your lams is making a jig with the same radius as your form, and then glue up your splice in the radius shape. You might want to use EA 40 with wax paper each side, and let it set overnight in the clamps.