Author Topic: Bending/gluing in reflex  (Read 1398 times)

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Offline DC

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Bending/gluing in reflex
« on: July 16, 2020, 06:43:32 pm »
I was gluing some reflex into a limb yesterday and I went a little too far for the quality of the wood I have left. It was Bamboo Yew and the Yew broke. I unwrapped all the bike tube and wiped off the epoxy. I'm in the process of making a new limb. This piece is still iffy quality. If I steam maybe half the reflex into it first and then bend it some more after glue up does the steaming first make it easier to bend. I'm not trying to bend it any further. I just want to bend it as much as before but hopefully without breaking it. Hope that's clear ;D

Offline PatM

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Re: Bending/gluing in reflex
« Reply #1 on: July 16, 2020, 09:38:45 pm »
It sure does. All  you have to do is think of how much you can recurve  steamed wood.

bownarra

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Re: Bending/gluing in reflex
« Reply #2 on: July 16, 2020, 11:50:11 pm »
To state the obvious.....it is too thick!
Thinner lams work best alround.

Offline Dances with squirrels

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Re: Bending/gluing in reflex
« Reply #3 on: July 17, 2020, 06:03:57 am »
If you go that route, steam and bend the whole way. It may spring back a wee bit, but you can make that up during glue up. It will also let you know if it's going to survive the bend before you bother with the glue.

For more pronounced reflex and recurves of 'slats/lumber' type blanks, I like to make them as trilams, or saw a kerf into the end of a blank and glue a short lam into it while bending everything during glue up.. That allows it to bend farther and more easily, without breakage.
Straight wood may make a better bow, but crooked wood makes a better bowyer

Offline scp

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Re: Bending/gluing in reflex
« Reply #4 on: July 17, 2020, 08:23:32 am »
DC is going for records. Steam bending might negate the benefit of "prestressed" glued-in reflex. Same goes with kerf cuts. As said, thinning the yew slat might be the better option, even if belly overlays become necessary. Just a speculation without any experience.

Offline DC

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Re: Bending/gluing in reflex
« Reply #5 on: July 17, 2020, 10:25:30 am »
DC is going for records. Steam bending might negate the benefit of "prestressed" glued-in reflex. Same goes with kerf cuts. As said, thinning the yew slat might be the better option, even if belly overlays become necessary. Just a speculation without any experience.

No real records involved, just a personal goal. Originally to break 200@10gpp, now to improve on that.
If you go that route, steam and bend the whole way. It may spring back a wee bit, but you can make that up during glue up. It will also let you know if it's going to survive the bend before you bother with the glue.

For more pronounced reflex and recurves of 'slats/lumber' type blanks, I like to make them as trilams, or saw a kerf into the end of a blank and glue a short lam into it while bending everything during glue up.. That allows it to bend farther and more easily, without breakage.
To state the obvious.....it is too thick!
Thinner lams work best alround.

 I steam the recurves in beforehand. They're static. It's just the reflex in the working limb. I have bend good wood on this caul. I'm just down to substandard wood an am looking for a way to ease the stress(both mine and the woods) a bit.

It sure does. All  you have to do is think of how much you can recurve  steamed wood.

Thanks everyone. As a pretty firm believer in glued in reflex I'd rather glue in all the reflex but I'll take what I can get. It would be nicer to just get decent wood. I'm working on that.

Offline DC

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Re: Bending/gluing in reflex
« Reply #6 on: July 17, 2020, 10:35:20 am »
I heat treated the replacement limb yesterday and it took about a half inch sideways bend. I figured that if I was going to steam that out I may as well put in some of the reflex. The first pic shows the quality of the Yew and the second shows the prebend and the caul. The recurve perches on top of the right hand end of the curve in the caul. Not too much further to go