Can set be "removed" from an old, shot in bow? Maybe so..TEST 2

[PEARL DRUMS]

That has been asked a million times. The standard reply is "no". I answered the same way to a point. I have heated up fades in the past and pushed a handle back to gain draw weight and move my tips forward. It worked every time I did it and the bow didn't get any worse. I had a 64" snakey Osage bow with 4" of set, and 57# @ 28". It was an early bow and I rushed the tiller and over stressed the bow badly. After two cups of Joe I headed to the shop to do battle with this experimental bow, what did I have to lose? I scraped the skins off the back, removed two sinew bands I had holding wind checks in place and removed the grip. I sanded and scraped the whole bow clean and smooth again. The first thing I did was literally remove half the weight on the last 10" of limb, she was a bit robust to say the least.  I lost about 3-4# of draw by doing so. I rasped the fades allot and got them moving properly. I lost another 3-4# doing that. I scraped both limbs evenly after I got the tiller corrected. By the time I done and the bow was all sanded smooth with 80 grit I lost a total of 12# in draw weight..............I still have that 4" of set I began with. I clamped her down the my 4" full relflex caul and set to work with my heat gun bending and forming the bow to the form. The instant I shut the heat gun off I darted outdoors with the caul and bow in hand and sat it all on our back deck to instantly chill in 25 degree temps. This was an experiment of sorts to see if "flash" cooling would impact the bow or the forming at all. I let it sit outside for 4 hours and then brought it in for another hour to acclimate, it was actually sweating a tiny bit. I inspected the bow top to bottom for cracks and found none, except for the two wind checks I started with. I un-clamped the bow and to my total suprise it held more reflex than any other bow I had ever built off that form, which is a bunch now.  I strung it about half brace and let it sit for 15 minutes. Then I pulled it to 20" several times over letting the wood removal take effect. I went out and shot it 20 times @ 20" and came back in and unbraced it, it held 1 1/2" reflex right away..........wow. I waited a half hour and braced it fully. Went out and shot another 20 arrows at 24", came in and unbraced her and the same 1 1/2" came right back in a snap.I braced it back up fully and went out and shot 20 arrows at 28" and came back in, unbraced her at she held 1" of relflex. Its been an hour unbraced and its back to 1 1/2". Several things happened today for me. I BELIEVE the flash cooling may play a part in holding my new shape more firmly, I BELIEVE that I removed enough over stressed wood from both the back and belly that the bow was able to be retrained. All in all I lost 5# of the original draw weight and gained at least 5-8 fps, quite impressive to me. I'm sure a few hundred shots from now it will lose some more, but it wont be nearly as bad as what I started with. I made up nearly 5" of tip movement alone. If you read this WHOLE bit, please feel free to comment, politely argue or discuss!

[Bevan R.]

Do you think the 'sweating' helped rehydrate it that fast. I would have expected it to blow with bracing that soon after heat bending.

[johnston]

Pearlie I will comment if you will bear in mind that I not only don't know much
but that I am happy with that. I BELIEVE that the wood removal and heating
of limbs on the caul changed the internal dynamics of your bow wood. Like
you said, you maybe removed the damaged "set" wood and basically heat treated
over what was left.

I would think that cold treating would keep the wood fibers in a state of
suspended animation ( frozen ) with little change.

Your bow changed but I think it was more skill than chill.

Lane

[PEARL DRUMS]

Do you think the 'sweating' helped rehydrate it that fast. I would have expected it to blow with bracing that soon after heat bending.

Nope. Rehydration is much deeper than surface moisture. That was just something I noticed. Hot wood plus cold air equaled moisture.

[MWirwicki]

Drums:  I suspect that you experienced the benefits of both heat treating and making better efficiency of your bow mass.  I suppose that I have a few additional questions:

1.  Did you heat the belly wood enough to "tan" the wood?
2.  Did you clamp the entire limb all the way to the reflexed caul prior to heating?  OR...   Did you just clamp the limb tips and gradually clamp the limbs to the caul as you progressed down the limbs with the heat gun?
3.  What bow design did the original bow have?  Pyramid?  Parallel?  Paddle?
4.  What bow design did you end up with?
5.  When you removed wood, did you remove any from the belly or mostly from the sides?
6.  Was the bow heat-treated originally?

I think that it was a very worthwhile experiment on your part and a way to bring new life to some of our "dogs".  It is discussed in TBB4 that heat-treating changes the cellular composition in the wood.  I would suspect that if you tried to improve on a once already, heat-treated bow that your results would not have been as positive.

Bring the bow to Marty's in January.  I'd like to see it!

[PEARL DRUMS]

Good questions Matt

1. no
2. I clamped the handle and heated my way to the tips. Clamping as I went.
3. Its a wierdo bow, all mine seem to be? The top is snakey and parallel while the bottom is pyramid like.
4. Same design, slimmed down.
5. I removed 97% of the wood from the belly and 3% from the back to clean it up and round edges better.
6. Nope, only steamed and cauled. No dry heat.

I plan on bringing bunches o' bows Matt. Makes me wonder just how many chips will even be made with all the shooting going on??

[blackhawk]

I copied n pasted what we were talking about in email here so folks can see publicly what I think about it.

 Here's my take on it. But first off..simply said...yes you helped that bow out. N once a bows not used anymore or retired then why not experiment with it....good job.

So, I don't know if you remember mikekeswick posted an experiment with a bow that had a few inches of string follow(set) in it. He cut it lengthwise down the neutral plane. The tension piece snapped back to normal where it was before it was made into a bow. And the belly piece remained in string follow. The set and compressed cells on the belly held the wood in string follow,and once he cut it the tension side was released from the forces of set in the belly. Interesting stuff. So, I think if you remove some of those bad cells(the worst are at the surface),and retiller and reheat treat it you then can gain a bit back. But I still don't think you gain it all back. There's just too much belly wood that would have to be removed to take it all out,and you'd end up with a kids bow before you got it all out.

As far as going from hot to cold,I have no clue what that will do,or help enough to know or see a difference. It never hurts to try something new tho. I have thought of that before,and ill apply cold acetone or denatured alcohol over a belly right after heat treating it just to cool it down faster so I can work on it sooner.

And yeah I've bent wood less than 24 hours after heating it with no problems either. But id rather be patient and wait,but its hard to do that

Unfortunetly im working 3 days this week. If were not moving this weekend im hoping to

[Buckeye Guy]

I wish I had a secretary to keep track of my experiments over the years !
I would heat treat the belly yet and finish it up!
As far as success removing set goes I do think it depends on what was already done to the bow!
Have fun
Guy

[Marc St Louis]

Interesting experiment but I seriously doubt there was any "flash" cooling and I don't believe there are any benefits to quickly cooling a bow anyway.  I remember heat-treating some bows during the Winter many years ago and using snow to cool the belly, the temps up here get considerably colder than 25 in the Winter.  There were no apparent benefits to doing that and the cooling process was no doubt much faster than just bringing the bow out in the cold. 

[Slackbunny]

I wish I had a secretary to keep track of my experiments over the years !
I would heat treat the belly yet and finish it up!
As far as success removing set goes I do think it depends on what was already done to the bow!
Have fun
Guy

I'm glad you said that. It just gave me the idea to start a journal containing the details of each attempted bow. I think that would be worth my time to maintain.

[PEARL DRUMS]

The bow is back to the original 1 3/4" of reflex after resting over night. Its hard for me to say that the cold didnt make a difference. This is food for thought next time somebody asks if set can be removed from a bow. Maybe the standard answer shouldnt be "no"? As with everything we do regarding this hobby, there are a million variables. The pic below was after another 20 full draw shots last night.

[artcher1]

I think you just got lucky Pearly .

[PEARL DRUMS]

I would rather be lucky than good any day Artsy! This stupid experiment hit me like a brick Im telling ya'. The bow went from worthless to a favorite in 6 hours.

[artcher1]

Now that's my old saying Pearly, so don't you be taking it ! Gotta love Osage ! Interesting............but be sure to let us know how the marriage is going after the honeymoon effect wears off .

What's the growth rings look like in your bow, big or small? Larger rings seem to benefit more from heat treating than the smaller ones I've noticed.

[PEARL DRUMS]

Top half is only one and a half rings thick, the bottom limb is four rings or so.