Heat treating vs trapping

[bradsmith2010]

trapping won't add weight or reflex to a stave
heat treating will,, they are two different applications to achieve different end results,,

[sapling bowyer]

Will heat treating add reflex automatically or do we have to bend it

[bradsmith2010]

heat treating can add weight automatically,, but the stave or bow would need to be in a reflex position when heated to add the reflex,,

[Danzn Bar]

trapping won't add weight or reflex to a stave
heat treating will,, they are two different applications to achieve different end results,,

Trapping helps tension strong wood from collapsing in compression......
DBar

[k-hat]

trapping won't add weight or reflex to a stave
heat treating will,, they are two different applications to achieve different end results,,

If you plan ahead as you should with trapping.... you can have the same effect.  With tension strong woods, you can make a faster bow for the mass without overstressing belly wood.  Tempering can be a quick "fix" for coming under weight, but planning ahead with trapping can yield an equal cast bow.  Not to mention you can heat in reflex without tempering, and still trap the bow, or temper, reflex, and trap if you want to I suppose. 

[PatM]

trapping won't add weight or reflex to a stave
heat treating will,, they are two different applications to achieve different end results,,

Trapping helps tension strong wood from collapsing in compression......
DBar

More accurate to say it helps compression weak wood from collapsing.

[willie]

planning ahead with trapping can yield an equal cast bow.

so either technique gives about the same performance gains.....

just how much improvement over untrapped and untempered can one expect?

shouldn't a self bow, a trapped self bow, and a tempered self bow, each with the same draw weight, give the same cast? 

[riverrat]

"It's about having all the tools at your disposal and using them wisely."very true Dell."You can also trap belly to back if necessary." so PatB, if i iused a crowned stave to make a bow and lensticular tillered the belly would you say its trapped belly
 to back?

[k-hat]

planning ahead with trapping can yield an equal cast bow.

so either technique gives about the same performance gains.....

just how much improvement over untrapped and untempered can one expect?

shouldn't a self bow, a trapped self bow, and a tempered self bow, each with the same draw weight, give the same cast?

No sir.  That's the same as saying all 50# bows have the same cast.  That just simply isn't the case.  The draw weight is just that.... the force it takes to draw the string back.  Cast has to do primarily with the speed with which the limbs return forward which directly impacts arrow speed.  Lighter outer limbs, for example, will return much faster than bows with heavier outer limbs.  Trapping and tempering bith have to do with compensating for weak compressive strength in certain woods, tbey have the added benefit of higher performance.  How much is gained?  A little or a lot, depending on the design, the magnitude of difference in tensile vs compressive strength, and of course the skill of the bowyer. 

Do an experiment... make all three and compare.  Elm is a good wood for this experiment.  While ur at it, go on and make a fourth tempered and trapped!

[sapling bowyer]

What I think is that when heat treating or trapping, the main goal is reached on both techniques as the compression is made stronger to match tension. When it comes to decide which one gives better cast, It depends and the only way to find out is to try. When we heat treat poundage gained per mass is higher so less mass is needed to get it in the desired poundage thus increasing cast. The thing with trapping is that we can reduce mass a lot while equalizing (or trying to) tension and compression forces. It depends on the ratio of pound per mass and cast per mass.The best way to find out is make two bows out of the same wood same dimension and same poundage but heat treat one of them and re tiller to the old poundage and to trap the other bow and compare the cast.

[PatM]

You can add reflex with heat treating. Trapping  just helps maintain what's already in the stave.

[sapling bowyer]

Does heat treating affect the density of the wood?

[PatM]

Don't let theory discussion get in the way of actually making bows. Good tiller comes first.

[willie]

K-hat-

thanks for the explanation of how a (trapped or treated) lighter-for-their-weight limbs can outperform.

theory vs. experience:  I was hoping some members that have tried the experiment, and can comment on the gains they have experienced.

elm is said to be a good candidate, but unfortunately, is not found where I live, however some of the local hardwoods (birch) , are reputed to be less responsive to heat treating.

[Chadwick]

Willie... buy wood.
I've had many wasted hours making birch bows. What town are you in? Wasilla here.
Michael