Author Topic: Second growth yew question.  (Read 534 times)

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Offline peacefullymadewarbows

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Second growth yew question.
« on: January 10, 2019, 08:00:47 am »
Hey guys. So, I have this yew stave I'm keen on doing an MR replica with. Its a very nice stave all around but when I received it I saw what is pictured in the link. There is this area of color change, drastic ring size difference, and most importantly the grain seems to not be linked. When draw knifing a slight shelf is left between these rings as if there is physical space between them. My guess is an event that broke the bark and caused second growth. My fear is will this spell doom for the stave in the form of a laminar separation? The shelf only runs about 2.5 inches long but it goes all the way through width of the stave. (both sides are pictured). It's also just shallow enough that it will end up probably about in the neutral plain of the eventual bow limb sense I was going to reduce the sap a little. Should I rough out the bow and saturate with thin super glue? Is this a non issue that I'm overreacting to? Never have had experience with this phenomena in any wood and it's a nice piece I'd like not to mess up. I know yew is resilient but nothing is invincible. Any thoughts are appreciated!

https://imgur.com/gallery/stnPxDb


Offline Del the cat

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Re: Second growth yew question.
« Reply #1 on: January 10, 2019, 09:17:43 am »
Ouch.
I think the best and most certain solution is to saw or split it along that line and glue it back together with Cascamite (aka Resintite).
That will put you back in control.
I know it sounds drastic, but anything else is just postponing the inevitable.
IMO Thin superglue doesn't penetrate as far as one might wish.
Sometimes one big major fix turns out to be easier and quicker than endless fussing around chasing your tail.
That's what I'd do if it were me.
Del
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Offline DC

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Re: Second growth yew question.
« Reply #2 on: January 10, 2019, 03:00:54 pm »
I think I'm with Del on this. Where would that spot be in the bow?
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Offline peacefullymadewarbows

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Re: Second growth yew question.
« Reply #3 on: January 11, 2019, 05:35:37 am »
Delcat: Rough... but I agree. All your points are valid. It's better to be overly sure of the fix than hope it'll hold up. Would you think like a scroll saw or band saw? I might set this one aside for awhile because I'm afraid I'll muck up the stave entirely simply trying to do this fix.

DC: Sadly it's 18 inches away from its tip, literally smack dab mid limb.

Another thought I had was breaking replica protocol a little and leaving the sap full thickness but I betcha the belly thickness that far down the limb is still too much. Will be mauling this one over for awhile.

Thank you both for responding. 
 

Offline DC

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Re: Second growth yew question.
« Reply #4 on: January 11, 2019, 06:43:25 am »
How thick is the stave in the picture? Is there any chance that you might tiller through that?
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Offline peacefullymadewarbows

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Re: Second growth yew question.
« Reply #5 on: January 11, 2019, 10:14:00 am »
You mean like an all heartwood bow? It is 21mm on one side and 25mm on the other side from the beginning of the sapwood to the second growth boundary.

Offline meanewood

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Re: Second growth yew question.
« Reply #6 on: January 11, 2019, 11:06:20 am »
I would go ahead and make the 'Mary Rose' style bow.

Treat this area like you would a knot.

Reduce the sapwood down to about 4mm everywhere except over this area, which you create a volcano shape, the peak being full sapwood thickness.

By reducing the sapwood, you will end up with lots of solid heartwood thickness on the belly side of this area.

You could also leave that area a little stiff when tillering

I think if you are making a authentic style bow, use a authentic method to overcome a problem.

Good luck which ever way you choose.

Offline Del the cat

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Re: Second growth yew question.
« Reply #7 on: January 11, 2019, 12:31:48 pm »
Delcat: Rough... but I agree. All your points are valid. It's better to be overly sure of the fix than hope it'll hold up. Would you think like a scroll saw or band saw? I might set this one aside for awhile because I'm afraid I'll muck up the stave entirely simply trying to do this fix.

DC: Sadly it's 18 inches away from its tip, literally smack dab mid limb.

Another thought I had was breaking replica protocol a little and leaving the sap full thickness but I betcha the belly thickness that far down the limb is still too much. Will be mauling this one over for awhile.

Thank you both for responding.
Either type of saw would probably do it, but it wants doing with great care to effectively saw along the line of weakness.
I had a similar problem with cracks on a grip, I split it off and re-glued it. Obviously easier on a short piece than a whole stave which is wy I'd probably saw rather than trying to split it off.
Vid of the handle job here which shows what I mean:- (it starts out of focus but gets better)
https://www.youtube.com/watch?v=O-7gam6aAS4&feature=youtu.be
Del
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Offline DC

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Re: Second growth yew question.
« Reply #8 on: January 11, 2019, 01:01:08 pm »
You mean like an all heartwood bow? It is 21mm on one side and 25mm on the other side from the beginning of the sapwood to the second growth boundary.
No I meant total thickness. Is there a chance that as you are tillering you will remove the problem. On my 105# warbow it is a shade over 1" thick 18" from the tip. With yours being 21 and 25 mm you are going to be just under that dimension. Do you know what draw weight you're after? If you're doing an MR replica you should  know how thick the limb will be 18" from the tip. I'd hate to see you go to all the work of Del's method and then scrape it all off while tillering. But if you do it like Meanewood says you may end up with a that crap just a mm or so under the belly.  The same thing could happen with Del's method but it would at least be glued down. Maybe a flatbow is the better option for this stave. The limb will be thin enough for all your worries to end up on the floor. I'd do some serious measuring.
« Last Edit: January 11, 2019, 01:15:22 pm by DC »
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Offline peacefullymadewarbows

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Re: Second growth yew question.
« Reply #9 on: January 12, 2019, 05:55:11 am »
meanewood: Thank you for your suggestion. That was my gut reaction when I discovered this. Treat it like a knot leave it prouder than the rest. But, the physics behind why this would break are a little more scary than the physics behind why a knot breaks. A knot is kind of like a hole through the limb you have to compensate for in thickness or width, but this even left stiff would still feel pull and push from either side of the shelf and them not being married could still spell Kaboom. ;D Thus, why I posted. Thank you for your input. I would jump at doing your suggestion except the stave is only 73" long so leaving a 3" stiff spot will put me in risky territory trying to get it back to 31". I was going to replicate the smallest bow on the MR I remember reading somewhere it was 73" long. (One wonders if it was only meant for the shorter arrows and thus more like a 28" draw) Have you dealt with this exact problem before with success? Your input is very appreciated.

Delcat: Thank you! Your video confirmed what I thought you meant. The downside of sawing I just thought of is the kerf created by the blade won't have quite as perfect of fit as from splitting, plus following the grain well since a saw can meander. But something as small as a scroll saw should leave such a tiny kerf as to be manageable. Were it happening in the last 12" or so I'd be more keen to try this, but so far down the limb I am fearful of screwing up the stave. I think I will nearly rough out the width dimensions of the stave while leaving full thickness alone and then reevaluate. Thanks again.

DC: So sorry. The total thickness is 40mm or about 1 5/8" it is also that wide and the stave is 73" long. The goal was to replicate the smallest bow on the MR b/c I remember somewhere saying it was 73" long. Alas, for months I have been trying to get my hands on the Weapons of Warre book with either a copy being available when I can't afford it or no copy being found when I can. Then, for Xmas my girlfriend surprised me with a receipt saying she bought it from Abe books. Very wonderful!... Well they've just notified us they lost it in the mail so are resending another copy. A bit frustrating. So, at the moment I do not know the exact dimensions of this bow. My 75" ntn 115# yew bow was 23mm 18" from nock so I might just make it with all sapwood left on. Yeah I even thought about scrapping the MR replica and making a more squashed profile longbow to get out of this. All of the above is on the table. I think once I get the dimensions of this bow I will rough out near to the width while leaving full thickness and then decide on how the shelf looks then and how to proceed. All input has been very appreciated and I will update on proceedings.


Offline WillS

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Re: Second growth yew question.
« Reply #10 on: January 12, 2019, 07:43:14 am »
The shortest complete bow was MR80A0763, and is 72" tip to tip.

It's 33.5mm X 30.5mm in the handle, 27.5mm X 24mm 500mm from the centre and 17.2mm X 16.2mm 800mm from the centre.

Offline peacefullymadewarbows

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Re: Second growth yew question.
« Reply #11 on: January 12, 2019, 08:18:09 am »
Thank you so much Will. And that's just straight line tapers between each dimension? Standard 12-14mm tip? Do you think this bow was made to draw to 30-31" or to stop at 27-28"? Thanks again. I'll see how that fits around the flaw in the stave and decide what to do.

Offline WillS

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Re: Second growth yew question.
« Reply #12 on: January 12, 2019, 02:38:55 pm »
I've not actually seen that bow in person, I imagine it's one of the bows in the actual museum.  If it follows the usual MR taper formula, it will be parallel until roughly midlimb, taper gently until about 8" from the tips and then taper dramatically down to the horns.  I don't trust the measurements in WoW however, knowing how inaccurate they are.  They're a good starting point, and it's an invaluable book to have but for proper replicas they're not close enough.

The "standard" tip is actually no more than 12.5mm.  14mm is huge for an MR bow!

I think most of those bows were probably being shot at around 29" to 30".

Offline peacefullymadewarbows

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Re: Second growth yew question.
« Reply #13 on: January 12, 2019, 03:28:40 pm »
All very appreciated Will. Alas, I think my chances of ever laying hands on an original MR bow are slim to zero so this will have to be my best bet. Although the whole not being able to thin the sap wood already seems to spit at the replication protocol. All of you have been very helpful. I am very appreciative. I will maul this over and decide how to take this stave forward.

Offline meanewood

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Re: Second growth yew question.
« Reply #14 on: January 12, 2019, 03:57:33 pm »
One thing I would add is, finish the width in this area now using a fine rasp and/or sandpaper in order to get a smooth finish and then show us a new photo how it looks from each side view.

If this is a short natural de-lamination between growth rings, I don't think it will affect the ability of this section to bend safely.

That stave want's to be a Warbow or firewood, no shame in that!