Steaming??'s

[whitewoodshunter]

I'm currently steam a curve( reflex) into a short( 57 ntn.) sinew backed pignut hickory bow and I have some questions.The reason I am steaming a reflex into the bow is that when I made the bow 4 years ago I made the tips and the handle fade outs to wide and thick resulting in about 3 inches of set the bow shot well but was sluggish and kept taking on set. I finally got around to fixing it I narrowed the tips and slimmed out the handle fades, making more of the limbs bend. During the steaming the sinew has become soft will it re-harden?? And how long should I let the bow dry out before I finish the tillering?? I used the pot method. Boiling water in a pot and placing the limb over the pot and covering the whole thing with aluminum foil. I let it steam for 1.5 hours.

[TRACY]

I wouldn't steam anything with sinew on it already. Hmmmm?

Tracy

[bowhuntinhillbilly]

i would believe that the sinew will re-harden

[Pat B]

The sinew should dry back out but I personally would give it at least a month to cure again under constant relatively dry conditions...in a room with a/c or in a hot box on low heat and a fan inside. I have never steamed an already sinewed bow and would not suggest it. Not only have you made the sinew soft but you have introduced moisture to an already dry bow and may have weakened the bond between wood and sinew. As the sinew dries and shrinks and as the bow wood also dries you can expect to develop drying checks in your limb and possibly longitudinal cracks in the belly from the stresses of the sinew drying and pulling the limbs.  Sometimes it is just better to leave an unsatisfactory bow alone and start another.
   A possible better route to take would be to remove the sinew, do the repairs or reshaping of the bow and put the sinew back down after the bow has dried from the steaming. Then give it a month of drying time before stressing it.        Pat

[Papa Matt]

The sinew itself will re-harden, it's the glue I'm worried about. Please, in the future, never steam an already sinewed bow. In this case, I would expect to take the sinew off, dry the bow out, and re-sinew it. JMO

~~Papa Matt

[whitewoodshunter]

The sinew was applied with tb11 if that helps. The bow really wasn't doing any good the way it was so I guess I'm not going to be out much if it doesn't work.But thanks for the repleys.

[Papa Matt]

If it was applied with TBII, so much for taking it off. It will be very hard to do that and then try to glue it back on. What you could do, is dry the bow out very slow, and then sinew wrap the area that was steamed, and likewise on the other limb so that it's symmetrically the same on each limb. I would call it a loss till you tried everything (or as much as you care to try). But if you love the bow, you can almost always find a way to save it. I'd let it dry and sinew wrap it. JMO

~~Papa Matt

[Pat B]

The TBIII will release at 150deg(F). The TB tech folks told me that. Even if it does dry out, I would worry whether the glue will continue to hold or not.     Pat

[JW_Halverson]

Heating sinew to steam temperature will denature the proteins (in other words, cook 'em) once they have a little moisture back in them.  Ever try to rehydrate sinew strands in hot water?  They shrink up, bulk up, and never work right.  I have tried to recover sinew from a bow and was utterly frustrated by the cluster-flustered mess it became.  I ended up simmering the whole mess down when I made the next batch of hide glue.   Trust me, you could have reflexed a dozen bowlimbs with what came out of my ears and toasted another dozen hickory bows with the blue streak of cursing outa my mouth.  If you had used hide glue or unflavored gelatin (another form of hide glue), I would say scrape it off, rehydrate and simmer it down slowly, recycling the hide glue and converting the sinews to more glue.  I believe TBII is a latex derived compound so I do not know if you will ever be able to isolate the sinew from the glue.  

All you composite bow makers out there...Ever heat bend a sinewed limb???

Good luck whitewoodshunter, keep us posted on your results. 

(and a side note...I am always amazed by how we bowscrapers turn ourselves inside out to reveal our own 'tricks of the trade' rather than hoard our hard-won knowledge and experience)

[Papa Matt]

I agree JW. We are a very rare breed that for some reason loves to help and share our knowledge. I also agree 100% about heating sinew and what it does, tried that ONCE and will NEVER do it again. Found out the hard way with some very nice whitetail leg sinew that I was going to soak in hot water and then apply as a bow backing. RUINED IT. I hope everyone listens when we say this. I would hate for anyone to ruin their sinew like I did.

But the possibillity exists that Whitewoods coating of the sinew in Titebond II could have saved it. The reason I say this is that I have broken arrows before and tried to salvage the sinew from the feather wrappings and arrow points, which I apply with Titebond II. I have submerged the shafts in relatively water before for up to 20 minutes and some I've had to give up on and just cut off, because the glue just wouldn't let go and seperate. But like I said in the earlier post, he may be better off to just let the entire bow dry out slowly and then try to wrap it, as opposed to trying to take it off.

It would of course help to see the bow and try to asses what kind of effect the steam has had on the sinew backing.

~~Papa Matt   

[JackCrafty]

All you composite bow makers out there...Ever heat bend a sinewed limb???

I'm guilty of heat bending a sinewed limb.


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[whitewoodshunter]

I failed to mention he sinew back was covered with black linen. I don't know if that will help or not?

[JW_Halverson]

Hey jackcrafty....tell us what happened when you bent the sinewed limb.  Did it work? Don't be holding out on us!

[JackCrafty]

JW, I ended up with a big ole' dent in the sinew and no change in limb shape.

I guess the sinew/glue was not completely dry, the heat softened the area, and when I bent it (trying to add more recurve) the sinew squashed like a soft spot on a ripe peach.

[Papa Matt]

So did you keep the bow or junk it out?