How can I reduce string follow?

[red hill]

Help, guys!

Last summer I made a hickory backed hickory longbow that has taken over 3" of set.

I want to make a hickory backed osage about like the bow I sent Roy during the trade. After shooting in the trade bow, I noticed it was retaining some string follow.

I had tried to glue in about 2.5" of reflex but it didn't appear to help. Just figured set was destined to occur.

What would be a good technique for reducing the amount of string follow?  

Could I shape the osage to profile, heat treat reflex into the stave and then glue on the backing? If so, should I also heat reflex into the backing before glue up? Should bow thickness be tapered before heating?

Please help!  

[beetlebailey1977]

I believe keeping the moisture content down around 6% is very important on hickory.

[PEARL DRUMS]

How long and wide is the bow, and what is the draw length? Sounds like maybe its under built. Just a guess.

[John Scifres]

Design first.  Make it wide enough and/or long enough for the wood characteristics, draw weight and draw length you are targeting.  Bow length is determined by draw length.  Bow width is detemined by draw weight.

Dry wood is next.  It must be dry.

Tillering technique is imortant too.   Try not to draw it when it is too heavy.  Ideally, we would not draw a bow until it is perfectly tillered and at draw weight and length.  We can't meet that ideal unless very good or lucky so we try to minimize the damage that occurs during tillering.  

For me, for a flat bellied bow somewhere around 50#, I like to get the limbs a little less than 5/8" thick and very even before even starting.  This is going to get it bending and if I've done my job right, it should be pretty close to even bending.  No major dips, no hinges, no stiff spots.  From there it's just hitting weight.  

Gluing in reflex is a help.  I assume a 2" reflex will result in less than 1" of follow.

[red hill]

Beetle, the hickory was was demensional lumber from 3rivers with the hickory back. I don't have a moisture meter but in South Ark humidity is a killer during the summer.
The materials I'm using for the osage bow is also dimensional lumber from 3rivers. So chances are it's dry and seasoned.
Pearl, The length will be 62" n-t-n with width about 1.75" and my draw length is 26". I'd like a bow in the 50-55# range. (Usually shoot in the 40# range but Keenan's ambush bow feels great at 50#.) The hickory backing will have to be thinned but that won't be a problem.
I've attempted one selfbow from an osage stave and was happy with it but a split occured. Still have to allow my osage to season considerably longer so I'm using the 3rivers boards.
John, the belly and back will be flat since I'll use dimensional lumber. Would heating in reflex before glue up be acceptible?
Stan

[Shaun]

Most set occurs during the tillering process. The old saying is "dry wood expertly tillered" makes a good bow. No harm in gluing in some backset or heat inducing some backset on staves.

[PEARL DRUMS]

I have built a few HBH's and they all had 2 3/4" of reflex glued in, they ended up dead straight after several hundred shots. They were 68" long, 50-55#'s @ 28" and a bit narrow for hickory, about 1 5/8".

[red hill]

My HBH is 1.5" wide, .5" thick, and 68" long. Earlier in the week I clamped it on a caul and heated the belly a little. Not much, didn't want to heat the limbs through and screw up the glue holding the backing on. Today the bow is almost flat. Of coarse I haven't strung it yet. Originally there was no reflex at glue up.

Shaun, that was in my mind. I exercise the limbs at least 30 pulls between scrapings while tillering. That translates into a lot of bending through the process.

[John Scifres]

The theory is that gluing in reflex is more effective than heating it in and then gluing.  This pre-stresses the limbs and increases the energy storage capability.  That all goes beyond my analysis comfort so I just take it as it is.  Plus I like gluing in shapes.  It has a WOW factor to it.

Your design sounds OK.  Make sure and store your wood indoors in an air conditioned space so you take advantage of the lowest RH available.  It helps to know the RH in your storage area.  Get a hygrometer (humidity meter).

[Roy Steele]

Here's a couple things that will help. I don't beleive I've had a bow in the last 10 or so bows that did'nt keep some reflex and havn't had one over and inch in a long time. REMEMBER it dosn't matter what you do or how good you started out WOOD IS WOOD.
  I know many people will not agree with SOME OF THE WAYS I BUILD MY BOWS but the bows don't lie. Just the way I've come to do it. I DON'T exspect anyone to follow me. JUST THE WAY I'VE COME TO DO IT.
  (1) I don't use heat to add reflex or on any moving parts (limbs). I will heat and bend handles to line up tips or flip tips if the person wants them done. But I perfer straigt limb bows for hunting myself.
  (2) I add my reflex while the stave is green. By taking it down to simi bow form. I know no ones taught to begain like this and it's alot of work before you start the bow bow the rewards are great.
  I had my reflex by placeing the stave (simi bow) between 2 saw horses. Either by adding weight (cinder blocks)or rachet straping it down to the foor. I've found that if I add 2 inchs of reflex by doing these things I can keep a little or most of the reflex. And it will stay.
  (3) When I get to tillering I put it in the hot box before each time I work it. This gets rid of the relitive humity (moisture). The outer wood has soked up. EXSPECIALLY WITH WHITE WOODS.
  (4) I never but excess stress on my limbs. Meaning never leave the bow on the tillering tree locked in place at full draw. Build a tillering tree with a scale and pully system. Not one with the notchs where you have to leave locked at full draw and steping back to look at  your tiller.
   NEVER GO PAST YOUR INTENTED DRAW WEIGHT.If you doing this it's putting unneeded stress your buting on your limbs.
  (5) People forget about the finishing part. And may leave it for a while when shooting it in or what ever at this point. But at this point the relitive humitys (moisture) forgotten about. Then they finish and seal the bow with the exture mosture in the bow.
  I put mine back in the hot box for and hour take it out then seal the bow. Areas where the humity high (moisture) it will matter in some woods. I do all bows this way.
  It's all the small things that over looked that matters in set and string follow.
  I'm sure these will help it has me for years.

[Aznboi3644]

one thing I found out with hickory...It loves to be DRY...like dry dry.


I had a board I thought was pretty dry since it was in the A/C basement for a year.  Well that bow took 2" of set.

I heat treated in some reflex...too much actually.  Accidentally heated in 7 INCHES of reflex...then I removed some reflex with heat and got it down to 4" of reflex.  After retillering the bow was again 45lbs@26" but retained about an inch of reflex.

It went from a soggy shooter to a high brace tension screamer.  Thats when I fell in  love with heat treating and hickory lol.

[red hill]

Thanks, guys, very good advice.
Roy, you brought up some interesting points I'd not considered. One of the things that make this such an outstanding forum is the attitude toward people seeking help.
John, I think I'll go with glueing in a little reflex and leave off the heat gun.
My HBH kept some of the reflex after being strung and then unstrung. It felt as if the poundage was back up slightly. Probably a temporary fix, you think?

[red hill]

Oh, well, I glued up this bow. Put about 2" of reflex in it. Now its cooking in the heat box. We'll see tomorrow.
Stan

[red hill]

This morning I took the bow out of the heat box, ground off the excessive glue (used smooth-on) and sanded off tool marks.  I got the bow to a profile and she looks good.
I didn't clamp the bottom tip well enough and found a dry spot at the end of the bow. Plan to fill that with super glue.
She has just under 2.25" of reflex, is 62" tip to tip, and 1.25" wide at the fades going out 6".  Limbs are still 5/8" thick plus the 1/8" hickory backing. Tips are .5" but I plan to take them to 3/8" when finished. Handle riser is 1 5/8" thick because I glued an accent of the hickory between the handle block and bow stave/board.
I tried to take some pics but the camera batteries are dead. They're charging now so maybe later this evening I'll be able to post pics.
I plan on at least 50# @ 26" for this bow. Any ideas how much I can expect to scrape off during tillering?

[Bob at Work]

sounds like you will have what you are after this time...gluing in the reflex and putting it in your hot box between tillering sessions will go a long way towards a great shooting bow that will take way less set...and I live in Arkansas too...HBO makes an excellent hunting bow.  Post some pics!
Bob

[red hill]

Bob, I hadn't considered putting the bow back in the heat box between tillering sessions. You mean for short periods of time, I would think, correct?
I'm beginning to see more and more Arkansans on TG and that's encouraging.
I cut osage in Yell county about half way between Russellville and Mena. Ever heard of Gravely, Briggsville, or Rover?
Been trying to post pics, I'm technologically screwed up! Photobucket isn't cooperating with me lately and my wife has been too busy to help lately.

[red hill]

[red hill]

 
 t.com/albums/ae45/stansims/IMG_7433.jpg[/IMG]
 
 
a few pics of the finished bow

[KellyG]

Nice bow Red hill. I really like them tips.

[red hill]

Thanks, Kelly. My wife posted the pics for me last night. Sorry they're so large. Forgot the full draw shot! Hopefully, There will be some pics of this bow on here from its new owner???