Author Topic: another "cutting backing" question...  (Read 4270 times)

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Offline upstatenybowyer

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another "cutting backing" question...
« on: February 22, 2018, 12:06:00 pm »
I'm assuming that cutting a backing strip from the outside of a tree would be ideal? If so, would it be a problem that the outside of a tree has an uneven surface, creating a strip with varying thickness?

Is it a better bet to go with a strip that is quarter-sawn, with growth rings running parallel down the strip?  I'm guessing plain sawn strips would not be good.

« Last Edit: February 22, 2018, 12:10:11 pm by upstatenybowyer »
"Even as the archer loves the arrow that flies, so too he loves the bow that remains constant in his hands."

Nigerian Proverb

Offline tattoo dave

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Re: another "cutting backing" question...
« Reply #1 on: February 22, 2018, 12:25:46 pm »
I would think the uneven thickness could be an issue. I'd personally go with the quarter sawn board backing.

Tattoo Dave
Rockford, MI

Offline PEARL DRUMS

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Re: another "cutting backing" question...
« Reply #2 on: February 22, 2018, 12:27:27 pm »
1/4 sawn back and flat sawn belly is a deadly combo. I wont call it fail proof, but its dang close if you use the right recipe.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline BowEd

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Re: another "cutting backing" question...
« Reply #3 on: February 22, 2018, 12:46:35 pm »
Jeff...With laminated bows quarter sawn straight growth ring line backing strips are the best way to go.As you assumed.With bamboo backing strip I like quarter sawn belly also but not totally necessary if done with osage.
« Last Edit: February 23, 2018, 09:43:00 am by BowEd »
BowEd
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Ed

Offline willie

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Re: another "cutting backing" question...
« Reply #4 on: February 22, 2018, 01:46:36 pm »
just curious PD, is there something that make flat sawn better for the belly? (or quarter sawn less desirable?)

Offline PEARL DRUMS

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Re: another "cutting backing" question...
« Reply #5 on: February 22, 2018, 02:01:12 pm »
willie are you me asking a redundant question so you can correct me later? Sure feels like it, considering your background and knowledge.


Personally. I like flat sawn bellies because the tools work nicer for me without waves or chatters. 1/4 on 1/4 works to, I think 1/4 on flat is easier.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline willie

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Re: another "cutting backing" question...
« Reply #6 on: February 22, 2018, 02:13:06 pm »
Quote
because the tools work nicer for me without waves or chatters.
thanks

Quote
are you me asking a redundant question......
not at all

Offline PEARL DRUMS

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Re: another "cutting backing" question...
« Reply #7 on: February 22, 2018, 02:17:04 pm »
I cant prove anything I type with science or numbers. I just build piles of bows and spit out commonalities I find as I go.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline Springbuck

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Re: another "cutting backing" question...
« Reply #8 on: February 22, 2018, 05:22:05 pm »
 Flat sawn is fine for an appropriate specie, but you have to be at least as picky about the grain as you would with a board stave.  Straight ring lines all the way down the face.

Quarter-sawn is definitely the best.  The only problem is that if it came from a wiggly log, it can hide front to back run-out because the nice straight grain lines look so nice.  That's pretty rare, but I've seen it.

Offline upstatenybowyer

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Re: another "cutting backing" question...
« Reply #9 on: February 22, 2018, 05:44:10 pm »
I'm planning on quarter sawing maple strips myself. I've got a ton of it. Sounds like that's the way to go. Does it make sense to cut them at about 1/4" thick and finish em off on the jointer?

I'd like to try splicing billets and backing them with the maple, like Marc does.
"Even as the archer loves the arrow that flies, so too he loves the bow that remains constant in his hands."

Nigerian Proverb

Offline Hamish

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Re: another "cutting backing" question...
« Reply #10 on: February 22, 2018, 06:10:18 pm »
 Plane sawn, rift sawn, quarter sawn  are all good for backings provided they are from a straight grained board. I haven't found any downsides to using plain sawn backings.
Quartersawn is the hardest to read for straightness of grain on the edge. The back with straight lines running length wise can trick you into assuming the edges are also straight. You need to look closely at the edges to see how straight the grain actually runs. Much easier to read the edge of a backing with rift or plain sawn slats.
Quarter sawn wood has a reputation for being the most stable, but I haven't noticed any difference once a backing is glued to a core/belly.

Offline willie

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Re: another "cutting backing" question...
« Reply #11 on: February 22, 2018, 06:14:08 pm »
Quote
Does it make sense to cut them at about 1/4" thick and finish em off on the jointer?
I don't care for jointing thin strips. If possible, I would joint the board, then cut the strip. One side will be ready for glue up, the other a sawcut finish.
joint the new sawcut on the board and cut the second,  etc.

Offline DC

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Re: another "cutting backing" question...
« Reply #12 on: February 22, 2018, 06:19:42 pm »
I've read that a jointer or planer polishes the surface and the glue won't stick. You have to sand it anyway. No experience myself but just saying.

Offline willie

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Re: another "cutting backing" question...
« Reply #13 on: February 22, 2018, 06:35:17 pm »
DC, actually you bring up something that I was going to comment on in the band saw vs table saw thread. I have always heard that a clean cut is better for gluing than a sanded surface. Of course a surface polished by a dull blade is another matter.

Offline Springbuck

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Re: another "cutting backing" question...
« Reply #14 on: February 22, 2018, 07:02:06 pm »
 "If possible, I would joint the board, then cut the strip."

THIS IS THE RIGHT WAY.

  " is there something that make flat sawn better for the belly?"

Willie, I know I'm not PD, but to me the answer is actually there in the TBB's.    Q.S. backing shows both summer and winter rings, making them less dense than the other cuts.  But, since almost all woods are stronger in tension than compression, even those "weak" in tension, Q.S. backs have enough, even plenty, of tensile strength, if they have the essentially perfect grain required. 

On the belly, the opposite is true.  Removing 10-20% of the density, elasticity, and strength of the belly by making it QS (exposing more winter wood) then IS harmful.   You might not notice with something like ipe, but with a "lesser" ring-porous wood, say black locust, that'll count a little.

That's my thinking.
« Last Edit: February 22, 2018, 07:47:47 pm by Springbuck »