Trad Gang

Main Boards => The Bowyer's Bench => Topic started by: Zradix on February 19, 2018, 09:04:00 AM

Title: Tri lam Question
Post by: Zradix on February 19, 2018, 09:04:00 AM
Hey Guys,

Do you all think it would be good-bad-or make no appreciable difference to leave a bow clamped in the jig from a dry run/practice for a few days to let the wood take the shape a bit before glue up?
...just curious.

I had an old scrap piece of maple clamped in my jig for a couple weeks while I was testing things out to see how I liked em.
I was sorta surprised how well it kept it's shape.

Seems to me it may add a touch of performance as the thick pieces on the the belly and core won't be trying as hard to be straight and instead will be trying to retain the jigged shape.

Also the backing should be under a little less stress as it isn't trying as hard to hold everything to shape.
...this part confuses me as you do get speed from some of that stress.

....maybe it would be best to clamp the belly and core up dry for a week or so...then after they've taken a bit of shape... glue everything up with the backing of course.

...just morning thoughts...lol
Title: Re: Tri lam Question
Post by: wood carver 2 on February 19, 2018, 09:08:00 AM
I've done it before and it can make your glue up a bit easier.
Dave.
Title: Re: Tri lam Question
Post by: Roy from Pa on February 19, 2018, 09:11:00 AM
Might not hurt, but it's the glue joint that holds everything into shape.
Title: Re: Tri lam Question
Post by: Zradix on February 19, 2018, 09:26:00 AM
WOOD CARVER 2...That could certainly be a plus too...lol. Did you notice anything different about the bow once it was done at all?

Roy...I agree..it's the glue that holds things to shape. I was just thinking this might relieve some of the stresses on the wood and glue.
...thing is I'm not sure if that's a good or bad thing...lol
Title: Re: Tri lam Question
Post by: wood carver 2 on February 19, 2018, 11:07:00 AM
I didn't notice any difference in performance. It just made the lams want to stay in place while I glued up. The glue still makes them slippery though, you still have to take care to keep it all aligned.
Dave.
Title: Re: Tri lam Question
Post by: BMorv on February 19, 2018, 11:08:00 AM
I would rather the glue and surface of the woods take the stresses than deform the wood to take the shape you are after.  Unless you are using heat, I would think there's some damage of the wood fibers to take and keep a bend like in your maple example.  
Just my thoughts.
Title: Re: Tri lam Question
Post by: BMorv on February 19, 2018, 11:12:00 AM
Kinda like leaving a wooden bow braced for a couple weeks.  I get a bad feeling just thinking about it.
Title: Re: Tri lam Question
Post by: mikkekeswick on February 19, 2018, 11:16:00 AM
I don't think there would be any appreciable difference. Saying that I don't think it is a good idea as any permanent deformation can only be set, thus robbing a little of the woods natural return speed. Like leaving a bow strung for too long.
Title: Re: Tri lam Question
Post by: Zradix on February 19, 2018, 11:26:00 AM
Good points guys.

I understand what you're saying about set.

I'm thinking this might cause "set"..but in the opposite direction thus maybe helping things out...
..who knows..lol
Title: Re: Tri lam Question
Post by: BMorv on February 19, 2018, 12:43:00 PM
Set is caused by broken wood fibers.  There's no fixing these broken fibers and the surrounding wood fibers now have to carry the load.  The still good fibers are prone to being overloaded at this point.  
Even if you are bending in the other direction, set is not a good thing.  

Not sure if you were joking are not with your last comment.
Title: Re: Tri lam Question
Post by: Zradix on February 19, 2018, 12:48:00 PM
nope not joking ...lol

I see what you're saying about broken fibers and other fibers having to pick up the slack.

Thank you.