Alignment help on BBI recurve

[Dan K]

Should I heat straighten the limb or in the handle?

[Del the cat]

The twist is in the limb... so straighten it in the limb. Hopefully steam won't over heat the glue?
If it was glued full width, maybe it needed exercising before being narrowed too much at the tips.
Sorry if that is just being wise after the event, but anything with reflex can be twitchy.
Could just try jigging it up with a weight pulling the twist out and leaving it for a few days... maybe with some v gentle heat, like a light bulb near to it.
Better to try the gentle persuasion before resorting to something that might leave it MBR.
(Mended Beyond Repair )
Del

[Dan K]

Good advice Del!  I'll start with a light bulb and see what happens.  You mention steam, what is the best kimd of heat in this situation or does it really matter?  Pros and cons?

[Del the cat]

The big advantage of steam in this situation is it won't get over 100 dgrees C. A temperature controlled heatgut would  also be good for something like that, I had one which wasn't too expensive... I ruined it by switching it off and not leaving it upright to cool... the innards melted
It also might be worth gluing up some scrap timber to test how the glue reacts to steam.
Del

[M-P]

Howdy,   I didn't seriously consider that the stave may have been glued up twisted.   I mean, I might glue crooked, fail to check or draw a new centerline and then trim to profile anyway...... but nobody else would do that!  Hopefully controlled heating and counter twisting will correct things, but the Ipe belly might resist such efforts.     Ron

[k-hat]

I'd do what Art/Del said.  I actually have done what Art said, and it worked beautifully (though not with Ipe).  Titebond is supposed to soften at about 150 degrees I think, but will be pliable at lower temps.  Even at 150 it doesn't just let go (in my experience anyway).  Just make sure you don't cook the ipe (if using dry heat, crisco works nicely here), take it easy and be patient (not my strong suit), and it's ok if it takes multiple sessions to get'r lined up.

You might try using a high wattage light bulb as Del mentioned with the bow in the form you used (I worry about losing/changing the reflex profile with heat), but secure the offending limb about as far off center on the other side of where it is now.  Surround the whole area with a mini makeshift hot box and monitor temp.  Maybe... it could work!

Good Luck!!

[Dan K]

Just to make sure I'm clear, I can heat and check for results and if it hasn't met my expectations it's okay to heat again repeatedly. I'm not sure about heat bending past the twist because this really isn't a bend its a bad glue up. Don't I want to heat and straighten to location and when the glue hardens again it should hole in that position?  I just don't want to switch the problem from one side to another.

[artcher1]

Dan, you're going to have to go way past straight to accomplish what needs done. Heat it, twist it, and pull it out and look at it. Do not leave it in place. For example, I like to see my correction stay a little past straight, and it if holds there, I've bring it back to where it needs to be. That way there's no question of any spring-back and having to reheat and do again.

[Dan K]

Okay folks. Here's a picture of my set up with the lightbulb and weight pulling the twist in the opposite direction.



Looks like it will work as long as the bulb gets hot enough. 100watts.  If I'm doing this wronged me know!  Thx

[steve b.]

Hope it works, Dan.  If it doesn't I would shorten the bow, shorten the handle (or eliminate it), and go from there.  MOo

[Dan K]

The light bulb worked!  Thx Del.


The limb in my hand is not the bad end although I'm going to straighten it too now that I now how.


now to scrape the rind off the boo and tiller. I was told to be careful and not damage the nodes. How clean do you need to get them and how do you know if you scraped to far?

[BowEd]

Hey Hey......Happy days are here again......LOL.Nice when a plan works.Congrats.

[Thesquirrelslinger]

you might just want to leave it.
But just scrape a little until it isn't smooth- the rind is a consistant color, the fibers look like effingglass.

[toomanyknots]

Cool, I will have to remember this one for sure! Nice save, is that light bulb a higher watt one?

[Del the cat]

Well done Dan .
It may be worth repeating the treatment, to over bend it slightly, in case it tries to relax back?
Del