New bow and removing string follow

How to make a Bow, a String or a Set of Arrows. Making equipment & tools for use in Traditional Archery and Bowhunting.

Moderator: Moderators

Post Reply
Message
Author
Sabinus
Posts: 138
Joined: Tue Mar 26, 2013 8:56 pm

New bow and removing string follow

#1 Post by Sabinus » Sat Sep 13, 2014 9:02 pm

IMG_1951.jpg
IMG_1951.jpg (58.65 KiB) Viewed 2680 times
IMG_1952.jpg
IMG_1952.jpg (49.68 KiB) Viewed 2680 times
IMG_1949.jpg
IMG_1949.jpg (58.37 KiB) Viewed 2680 times
IMG_1942.jpg
IMG_1942.jpg (56.53 KiB) Viewed 2680 times
Hi guys, thought i'd share a recent piece of bowyer-y, and a bit of anecdotal feedback on Dennis' string-follow-removal process. The bow pictured is a hickory flat bow, jute backed, 68" ntn and 52lb@28". The hickory is from a 2x2" stave I got at Otto's here in Adelaide. I sawed it straight down the middle into two edge-ringed boards. I glued on a jarrah riser and have wrapped the handle with some hemp thread to keep things pretty basic. I've cut a shelf into the riser to around 1/4" from centre.
A few weeks ago when I 'finished' this bow, the draw weight was more like 48lb @ 28" and the limbs had around 1 6/8" of string follow. I was a bit disappointed with the end result - she was a bit of a slug, albeit a stable, quiet, straight shooting slug! I'd gotten similar amounts of string follow in the previous two bows I've made, and was using progressively more care during the tillering process so as not to overstrain the limbs - seemingly for little improvement. The bow went up on my wall and I chose my new Bear Grizzly for the next few backyard shooting sessions.
Then I started thinking about what i would do with the other half of my hickory stave, and what i could do to really eliminate at least some of the set I've produced in bows up to now. I did some reading up on heat tempering a stave whilst tillering, to create a more compression resistant belly. Then I remembered reading the very interesting article produced and posted here by Dennis a while back re. heating a reflexed bow to reduce existing string follow. I decided to try the process on my latest bow, to see if it's performance could be improved.
I rigged up a very basic jig in which the bow was bent into 4 inches of reflex, wiped the limbs with vegetable oil and started heating with a heat gun. I spent about 35 minutes on each limb - longer than recommended in Dennis' article, but there was no scorching or toasting of the wood so I took my time. Later that night I took the bow out of the jig, to find it held almost 2" of reflex! After stringing and shooting the bow about three times now, the bow shows about 1/2" of set immediately after unstringing, only to settle just back into reflex a few hours later. Draw weight has increased by 4 lbs and strangely there seems to be less hand shock. Great result for a bow I thought I'd stuffed up a bit- now it's quiet, stable, and launches my 10grain p/p cedar arrows straight and quite pleasingly hard.
Thanks Dennis!

hunterguy1991
Posts: 859
Joined: Mon Jul 09, 2012 10:18 am
Location: Woodford Queensland

Re: New bow and removing string follow

#2 Post by hunterguy1991 » Sun Sep 14, 2014 10:38 am

That's a great looking bow mate, well done!!

Colin

User avatar
greybeard
Supporter
Supporter
Posts: 2992
Joined: Tue Feb 07, 2006 9:11 am
Location: Logan City QLD

Re: New bow and removing string follow

#3 Post by greybeard » Sun Sep 14, 2014 11:41 am

The bow has turned out well, and your bow proves the point that bows don't necessarily have to be expensive.

Was the jute backing applied after the heat treatment?

Daryl.
"And you must not stick for a groat or twelvepence more than another man would give, if it be a good bow.
For a good bow twice paid for, is better than an ill bow once broken.
[Ascham]

“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]

I am old enough to make my own decisions....Just not young enough to remember what I decided!....

User avatar
Stickbow Hunter
Supporter
Supporter
Posts: 11637
Joined: Sat Jul 26, 2003 8:33 pm
Location: Maryborough Queensland

Re: New bow and removing string follow

#4 Post by Stickbow Hunter » Sun Sep 14, 2014 2:02 pm

Great result mate!

Jeff

Sabinus
Posts: 138
Joined: Tue Mar 26, 2013 8:56 pm

Re: New bow and removing string follow

#5 Post by Sabinus » Sun Sep 14, 2014 2:15 pm

Thanks for the positivity, Colin and Jeff!
Daryl, it's true a bow needn't cost too much to make. I'm not sure if this is the one to prove that point though -purchased the hickory from a 'boutique' timber supplier. It's the only place in S.A. where you'll find hickory, and boy don't they know it! two bows worth of timber cost $110. It's not red oak cheap, but when the backing material costs about $1.50 per bow, the bottom line ain't too bad I guess…...

To answer your question, the backing was well in place by the time I ran my little experiment. Dennis said in his article that his process had been performed on backed and unbacked longbows with no trouble, so I went with that. During heating, when the belly of the bow was too hot to touch, the back of the bow felt warm, at most. I wouldn't hesitate to try this again.

Next bow however, I'm planning to reflex and heat the timber during tillering, to try and temper the belly fibres before I crush them into a cast-robbing set. We'll see if an ounce of prevention may beat a pound of cure!

I'll keep you posted re. the results.

Daren

Darren

User avatar
rodlonq
Posts: 2096
Joined: Wed May 06, 2009 3:02 pm
Location: Ingham NQ

Re: New bow and removing string follow

#6 Post by rodlonq » Mon Sep 15, 2014 4:19 pm

Looking forward to finding out your results Darren. Thanks for taking the time to post your interesting article.

Cheers.... Rod

Hamish
Posts: 309
Joined: Wed Oct 18, 2006 7:42 pm
Location: Sydney

Re: New bow and removing string follow

#7 Post by Hamish » Tue Sep 16, 2014 12:32 pm

The heating results worked well, the bow looks good. Using a water based glue for the backing can reintroduce moisture into hickory. Hickory has a reputation for taking excessive set due to moisture, though 1 & 3/4" of set is in the acceptable range.
I have bought hickory for bows from Otto and they know to give you straight grained stuff, so you really don't need to back it anyway.

Dennis La Varenne
Posts: 1776
Joined: Sun Sep 07, 2003 10:56 pm
Location: Tocumwal, NSW. Australia

Re: New bow and removing string follow

#8 Post by Dennis La Varenne » Tue Sep 16, 2014 7:44 pm

It looks like it turned out pretty well then, Darren. It is good to have some corroboration of a technique.

You have some very nice curves in your bow. Personally only, I would have made the dips shorter to allow even more of the limb into work and spread the bending load lengthways more. I would not do anything to this bow now of course. Leave well enough alone.

Hickory is not a very compression resistant wood which is probably why yours took so much set originally. But it is VERY tension resistant and it is very reliable and tolerates a great deal of abuse. The only other wood back then which equalled the tolerance of abuse of Hickory was Lemonwood or Degame, but it was also a near performer to good Yew without the bowyering difficulties. Heat removal of set in my Lemonwood bows improves performance much better than with Hickory by as much as 5 - 10lbs in draw weight. It can be extraordinary sometimes, especially with the better grade of Lemonwood. Pity you cannot get it now though.

Many of the old bows in my collection are Hickory and no matter how much reflex I put into them within reason, they do seem to lose most of it over a short time. These bows mostly had very shallow convexed bellies and dead flat backs even though they were called flatbows in their day - not the best way to distribute bending loads.

For the future, if you make another bow from Hickory, try trapezoiding the limb cross-section so that the back surface is about 20% narrower than the belly. This will help distribute the tension-compression loads between back and belly much better and lead to much less set - tillering being OK.

The reduction in handshock you comment on is probably due to your bringing the limbs back into synchrony due to the relative amount of bend you heated into the limbs.
Dennis La Varénne

Have the courage to argue your beliefs with conviction, but the humility to accept that you may be wrong.

QVIS CVSTODIET IPSOS CVSTODES (Who polices the police?) - DECIMVS IVNIVS IVVENALIS (Juvenal) - Satire VI, lines 347–8

What is the difference between free enterprise capitalism and organised crime?

HOMO LVPVS HOMINIS - Man is his own predator.

Dennis La Varenne
Posts: 1776
Joined: Sun Sep 07, 2003 10:56 pm
Location: Tocumwal, NSW. Australia

Re: New bow and removing string follow

#9 Post by Dennis La Varenne » Thu Sep 18, 2014 5:15 am

Daren,

Another thought I had today about your original attempt which produced 1.75" of set which is not really bad, is that the Hickory was a bit too wet when you built it. That is a well-known killer of bow performance.

If you read up comments by Tim Baker adn Dan Perry in TBB, you will find that Hickory, unlike most other wood, reaches its optimum bending strength at a moisture content fo around 5 or 6% which is splinter dry in most other wood. You can force dry it much more than other wood without rupturing wood cells apparently. A hand held moisture content gauge is very useful, but after drying it to local ambient moisture content when it has lost as much weight as possible, the glued up stave is worth heating it in the direct sun in a black tube with the ends open to cause cross-flow ventilation until it dries even further again and loses even more mass.

If you are in northern Australia with a wet season, do it all in your dry season when the ambient humidity is lower. Do your work after you have force dried the glued up rough-shaped stave to minimum moisture content, expecially if you can measure it. After you have dried it, it won't pull in much moisture content if you can get the bow to shooting stage in the next few days afterward and slop a coat of varnish on it to seal in what moisture is inside and keep out what is outside. Then just proceed to final finish in the usual fashion.
Dennis La Varénne

Have the courage to argue your beliefs with conviction, but the humility to accept that you may be wrong.

QVIS CVSTODIET IPSOS CVSTODES (Who polices the police?) - DECIMVS IVNIVS IVVENALIS (Juvenal) - Satire VI, lines 347–8

What is the difference between free enterprise capitalism and organised crime?

HOMO LVPVS HOMINIS - Man is his own predator.

Sabinus
Posts: 138
Joined: Tue Mar 26, 2013 8:56 pm

Re: New bow and removing string follow

#10 Post by Sabinus » Sat Sep 20, 2014 8:36 pm

G day Dennis, thanks for the comments. As usual , you make plenty of interesting points to take on board. Although I've read about hickory's heightened demand for dryness, I have not so far proactively tried to drive extra moisture from any of the wood I have made a bow from. I guess I've just assumed that the processing to get it to point of sale has it in a suitable state for my purposes. Thats probably a long bow to draw (pun totally intended) when I'm buying pick handles to make a takedown bow out of!

I have a beautiful 6 foot, 2x1 inch edge ringed board to make my next bow from, and thanks to your suggestions I believe I may try 'trapping' the limb cross section to try and exploit the hickory's super tension strength and protect it's more suspect compression tolerance. It's really convenient summer is around the corner - that will give me the chance to perhaps rough the bow out and then make use of the scorching dry summer we get here in Adelaide to get the bow 'splinter dry', to borrow your term. I know under two inches of set isn't exactly a disaster in a self bow (yes I use that term loosely) but I'm really keen to find out just how hard hitting a bow i can coax out of a piece of wood with a rasp and patience! And although the comparison is unfairI'd love to try some sinew one of these days, and recurved tips, but like yourself, I'm so far sticking to the basic straight-laid design as i love the simplicity of the materials, making process, and the aesthetics of the finished weapon. I figure that once I know how to make a really good longbow (yes another loose term!) then I will look at some fancier options if the mood takes me.

Thanks again Mate,
Darren

Dennis La Varenne
Posts: 1776
Joined: Sun Sep 07, 2003 10:56 pm
Location: Tocumwal, NSW. Australia

Re: New bow and removing string follow

#11 Post by Dennis La Varenne » Sat Sep 20, 2014 11:00 pm

Darren,

Trapezoiding limbs with low compression strength is a sound principle. Getting Hickory to its optional dried state is a bit harder and you really need a little hand held moisture meter to check it. Any wood will only lose moisture to equalise with the ambient humidity and no more.

Your use of the term 'longbow' is correct. It is the American version of the longbow which we commonly see. The Pommies only refer to them as Flatbows. Their separation of the terms is far more strict.

I have not used sinew and have no particular interest in it. However, in my reading on the topic, it is of little use on a longish bow because the required amount of sinew to be of any benefit in holding even moderate reflex in a limb weighs more than the wood itself and the consequent increase in limb mass slows them down considerably. It is best in bows no longer than 60 inches maximum with broad inner limbs and fine outer limbs.

As you may have read elsewhere, I mentioned in a post that 'self-bows' are bows made from a single stave. Bows with glued on handle risers of a different specie are composite bows. Small additions of a foreign material such as tip overlays and horns, etc which are not working parts of the bow don't count. Risers are part of the working bow because they control the amount of bend which the limb takes additionally to being a handle.
Dennis La Varénne

Have the courage to argue your beliefs with conviction, but the humility to accept that you may be wrong.

QVIS CVSTODIET IPSOS CVSTODES (Who polices the police?) - DECIMVS IVNIVS IVVENALIS (Juvenal) - Satire VI, lines 347–8

What is the difference between free enterprise capitalism and organised crime?

HOMO LVPVS HOMINIS - Man is his own predator.

Post Reply