Author Topic: How to cut backing strips?  (Read 5677 times)

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Offline Eastman

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How to cut backing strips?
« on: August 03, 2012, 02:13:36 pm »
Hey all,  i went to the lumberyard and after going through about 20 boards i found a pretty straight-grained piece of white oak :D, which i hear is just about even with hickory as a backing wood. After cutting it in half, i have two similar pieces 72'' long, 8 1/4'' wide and 3/4'' thick.

How do i go from here to turn it into backing strips?
''The joy is great of him who strays, in shady woods on summer days, With eyes alert and muscles steady , His long-bow strung, his arrows ready''  -Maurice Thompson

Offline Eastman

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Re: How to cut backing strips?
« Reply #1 on: August 03, 2012, 02:15:44 pm »
That last pic is the bottom side of the board shown in the first pic. do i cut the wavy part off first?
''The joy is great of him who strays, in shady woods on summer days, With eyes alert and muscles steady , His long-bow strung, his arrows ready''  -Maurice Thompson

Offline bubby

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Re: How to cut backing strips?
« Reply #2 on: August 03, 2012, 06:29:46 pm »
i cut mine a little heavy on a tablesaw and then run thru a thickness planer, and w o makes a great backer , Bub
failure is an option, everyone fails, it's how you handle it that matters.
The few the proud the 27🏹

Offline tom sawyer

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Re: How to cut backing strips?
« Reply #3 on: August 03, 2012, 06:39:05 pm »
Your board is quartersawn which is good, but does the grain run the length of the board down the skinny sides?  If not then you won't have continuous fibers when you cut thin slices off the board.

I've set up my bandsaw with a resaw blade and a fence, and cut thin strips off a board before.  Its tricky business but I've made some decent stuff this way.

I've never heard white oak is as good as hickory for backings.  My experience with oak is that it splits easy whereas hickory is a bear to split.  I think the cross-grain fibers help hold the backing together.  Not saying white oak won't work, I just think theres a reason people mostly sell hickory or bamboo backings.
Lennie
Hannibal, MO

Offline macbow

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Re: How to cut backing strips?
« Reply #4 on: August 03, 2012, 09:23:00 pm »
On the top picture the grain down the face is not bad. But the bottom picture showing the bottom looks to have considerable run off.
From the top pic. I would have cut 2 inch wide slats and then re sawn to a little over 1/8 inch thick.
The bottom pic. Complicates the issue if there is that much difference from front,to back. Might need to,cut at a,angle?

I've read white oak can be a decent bow, but doubt it will make as good of,a backing as,hickory.
Ron Mackenberg   Warsaw, MO.

Offline vinemaplebows

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Re: How to cut backing strips?
« Reply #5 on: August 04, 2012, 12:16:28 am »
Sorry that is just not the case, white oak while it will take slightly more set than good hickory makes a very good backing, infact I don't understand why it is not used more. White oak depending on species will break after hickory. Hopefully Badger will weigh in on this. :)
Debating is an intellectual exchange of differing views...with no winners.

Offline DarkSoul

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Re: How to cut backing strips?
« Reply #6 on: August 04, 2012, 05:43:15 am »
I also remember Tim Baker stating that white oak regularly breaks AFTER hickory breaks. Maybe the compression strength is not as good as with hickory, but in tension it is supposedly great.
The thing is, with oaks (all oaks) is that there is considerable variation in density (less so with hickory). Some boards can have loads of earlywood, making the wood very brittle and weak. Other boards, often those with thicker rings, have nearly all latewood and thus a dramatically higher specific gravity. Eastman's board appears to have an above average amount of earlywood. It's not useless because of this, but it could well be that this board is a bit weaker than the average hickory. Since the board is perfectly square, you can easily do a test for determining the SG. Accurately measure the volume in cubic centimeters, and accurately record the weight (on a food scale or a bathroom scale). This will tell you the SG of the board and is a good indicator for strength.
What concerns me more, is that significant grain runoff in the third pic. In my opinion, this part would not be suitable for backing strips. Since you have the board already, you could cut the board in half; use the first half (from the first pic) for backing strips that will be seamed in the stiff handle of the bow. Use the second part, with the poor grain, as billets that will have to be backed. A splice or seam in the handle of the backing strips is not a problem, as long as the handle is stiff.

To get back to your question HOW to make backing strips...cut the board into long slats 2"x3/4"
Then turn it 90 degrees so the side of 3/4" wide touches the table of your circular saw (tablesaw). Then cut in half, which will create two strips of each about 1/4" thick. That is a bit too thick, I think, so you can plane/sand them to about 1/8" or 3/16".
"Sonuit contento nervus ab arcu."
Ovid, Metamorphoses VI-286

Offline bubby

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Re: How to cut backing strips?
« Reply #7 on: August 04, 2012, 06:28:17 am »
while i've had hickory bows and backing's break, i've not yet had a quartersawn white oak bow or backing break, Bub
failure is an option, everyone fails, it's how you handle it that matters.
The few the proud the 27🏹

Offline Eastman

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Re: How to cut backing strips?
« Reply #8 on: August 04, 2012, 07:45:46 am »
Thanks for all the info guys. Unfortunately i dont have access to Hickory, so i'll have to make do with the white oak.
 
Darksoul, what exactly is the formula you mentioned for measuring SG?

So you guys would agree that after i got the board sawn into 2'' wide 3/4'' thick slats, that i could safely only rip it into 2 backing strips (per slat)?

Thanks alot
''The joy is great of him who strays, in shady woods on summer days, With eyes alert and muscles steady , His long-bow strung, his arrows ready''  -Maurice Thompson

Offline tom sawyer

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Re: How to cut backing strips?
« Reply #9 on: August 04, 2012, 11:14:57 am »
I'd hate to have to reduce a 1/4" slat down to 1/8" for backing.  Your best chance for a uniform thickness is right off the saw unless you have a jointer.  I think I'd go for something close to 1/8" to begin with and maybe get three per 3/4" piece.  I'm guessing your kerf will ne nearly 1/8" so this may be the most you can get.

Glad to hear white oak is good material, I was just offering my observations based on firewood processing.  I would rather see white oak go into wine barrels though!
Lennie
Hannibal, MO

Offline Badger

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Re: How to cut backing strips?
« Reply #10 on: August 04, 2012, 01:45:41 pm »
   I resaw on my bandsaw. Secret to a bandsaw in not to use your fence set up straight. Every piece of wood feeds through at a slightly offset angle. Draw a line on a pice of wood and feed it through your saw following the line, run about 12" and check the angle you are holding the board you are feeding. This is the same angle you will need to set up your fence. This will give you nice clean backing strips with only minor sanding.

Offline Eastman

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Re: How to cut backing strips?
« Reply #11 on: August 04, 2012, 03:04:59 pm »
While on the topic of bow backings, is it necessary to remove the rind off a boo back? Do you leave the nodes or do them as well? Preferably before or after backing the bow?
''The joy is great of him who strays, in shady woods on summer days, With eyes alert and muscles steady , His long-bow strung, his arrows ready''  -Maurice Thompson

Offline tom sawyer

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Re: How to cut backing strips?
« Reply #12 on: August 04, 2012, 07:04:16 pm »
You can leave it, or carefully scrape it off to get the warm banana yellow underneath.  Leave the nodes like they are, and be careful when you scrape the rind in those areas.
Lennie
Hannibal, MO

Offline DarkSoul

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Re: How to cut backing strips?
« Reply #13 on: August 05, 2012, 08:14:34 pm »
Necessary to remove the rind off a boo back? No.
Necessary to leave the nodes raised? YES!
You can sand/scrape down the rind (as long as you leave the nodes standing proud) up to the fibers. The rind is noticeably softer than the fibers. The fibers are streaked, while the rind is a uniform color.

specific gravity=weight in gram (divided by) volume in cubic centimeters.

You can Google more info on wood specific gravity, if needed.
"Sonuit contento nervus ab arcu."
Ovid, Metamorphoses VI-286

Offline Marc St Louis

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Re: How to cut backing strips?
« Reply #14 on: August 07, 2012, 02:53:09 pm »
I've been taking the nodes down on Bamboo for many years without any problems and I've not had any failures because of it.  You just need to be careful when doing it to make sure you don't go too far.  All you want to do is take the crest of the node down to where the power fibers start to come together and no further
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