Primitive Archer
Main Discussion Area => English Warbow => Topic started by: peacefullymadewarbows on January 10, 2019, 10:49:59 am
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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
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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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I think I'm with Del on this. Where would that spot be in the bow?
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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.
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How thick is the stave in the picture? Is there any chance that you might tiller through that?
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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.
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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.
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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 (https://www.youtube.com/watch?v=O-7gam6aAS4&feature=youtu.be)
Del
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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.
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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.
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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.
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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.
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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".
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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.
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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!
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Yes! I was planning to do just that! I'm hopeful it'll look a little less angry when narrowed. The stave feels your motivation haha! ;D thank you.
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Small Update: I narrowed the problem area on the stave down to about 35mm wide. The final width will be 27.5 mm in that area based on Will's dimensions. So, I didn't want to get too close before final decisions. The growth boundaries look exactly the same. No worse no better. BUT, one important discovery was made. I decided to take some shavings that had wood from both sides of the boundary on it. They were draw knife shavings about 1mm thick. I took three of them in hand and split them along the rings, and to my surprise 2 out of three did not break along the dark line but rather in healthy rings near it. This indicates 1. the two colors are actually bound at least mostly prior to what I thought (them being totally unmarried) and the boundary could be as strong or nearly as strong as rings bound in the same session of growth (no injury). Question is do you guys think that is a strong enough test to change how I treat this area? Just wanted to update everyone. Thank you for reading!
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All the more reason to go ahead and make the bow you want.
That 'line' could be just a sap layer but whatever it is I don't think It will have much effect on that areas ability to bend safely!
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All the more reason to go ahead and make the bow you want.
That 'line' could be just a sap layer but whatever it is I don't think It will have much effect on that areas ability to bend safely!
I'm not there to look at it so I'm guessing a bit, but go for it.
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meanewood and Dc: Thank you guys. I will go forward with replicating sans one aspect for sure. I am going to keep the stave 73" long as I am hopeful to use this bow myself and I shoot at 31". I will retry this replica again with the 72" long when I have a similarly short stave to work with and see where it ends up at 29-30". My final decision to make will be thinning sapwood (bringing the line closer to the neutral plane) or leave it full thickness (having the line maybe taper out on the belly partially) and that I'll just have to go with my gut on. The sapwood is currently about 10mm. The MR bows had about 4-6mm of sap wood? Thanks again.
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Post some pictures when you get closer to final dimensions. I'd like to see where that feature :D ends up.
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The best way to determine whether you've got the sapwood thickness correct for a replica is to look *directly* at the back of the bow. If you've got the right sapwood thickness AND the correct cross section, you should see a strip of heartwood down both sides of the sapwood. If the sapwood is too thick, it wraps over the fat portion of the cross section, which means you'll not see heartwood. If the sapwood is the correct thickness but the cross section is not round enough, there will be a "corner" where the back meets the side of the bow, and you won't see the heartwood.
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Here you can see the back of my 130lb copy of MR79A0807 and you can see the heartwood along the sides. It ended up being about 3mm maximum I think.
(https://i.ibb.co/86xQkrF/IMG-20180110-143610207.jpg) (https://ibb.co/0h9z5CP)
And this is the 175+lb copy (same dimensions, same tree very different weight!)
(https://i.ibb.co/WF3JTFC/43562775382-f764b0a2e0-b.jpg) (https://ibb.co/HY28JYZ)
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Thank you very much Will. Notes all taken.
DC- Will do! Got a busy rest of week but hopefully this weekend I'll have it down to width and will post pics.
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https://imgur.com/dV0o4HF https://imgur.com/O0x4LKE
Brought down to 1mm over final width (29mm). Cabinet scraping should do the rest. This is what the spots look like. Plus my little grain blunder. Hopefully it'll come out with radiusing the belly. Haven't done thickness taper yet. Having the growing feeling I'll need to leave all sap wood for best chances of a survivable bow. Thanks for watching!
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How close is that to the final depth? That's the one I'm concerned with.
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Whoops! I got to thickness tapering today. Here's the two sides and belly view of the possible problem spot. Gotta scrape the last few tenths of a mm off and horn it then its ready to string up. https://imgur.com/dV0o4HF https://imgur.com/zSVzATF https://imgur.com/Xs7Yy6d
It rasped as one piece of wood. As in the two layers didn't seem to act separate while cutting across. I'm glad I decided to keep full sap. My thoughts are if the spot pops it'll hopefully pop as one piece and can be glued on like a belly patch.
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That looks OK. I'd still soak the area with CA if it was me. Try to get a pool of glue over the crack. I've noticed with CA that if you can keep a pool of liquid on the surface it soaks in better. If you just put a thin coat on and let it harden you won't get any more in. I may be wrong but that's what it looks like to me.
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Thank you for sticking with me DC. I will do just that. Worst thing that happens is that I have glue stains to scrape off if there's no where for it to soak into. Will update with how it's going.
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I would go ahead and get that 'tear out' sanded out before removing any more wood from this area.
Also fine sand the back, belly and sides 50-100mm either side of the problem.
It's easier to keep a eye on the problem if it's smooth!
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Hey all. Got some time together got this little guy horned and scraped to the exact dimensions of the original bow. The cross section is kind of between the gallion and squashed rectangle cross section that seemed to be most common. So, the bow essentially has a slightly trapped back.
Below is linked a video of it going to 25" on the tiller. I pulled it to 26" afterwards where it hit 90lbs. It was bolt straight from the get go and now has just shy of 1" string follow. I only needed to scrap the inner/mid limb of the right limb to get balance and this is what it looks like now.
https://www.youtube.com/watch?v=R0Qz4l4cJ9s
You'll notice that I have duct tape on one limb. That is actually duct tape with a piece of paper under it so it doesn't stick to the bow and leave residue. It is basically a catcher bandage if that spot decides to pop. It is not on there tight but simply a loose band to catch whatever wood might pop off. To my surprise the second growth spot has not budged. I haven't heard a peep and upon inspection there is no gaps observed. Granted I did soak it in CA glue before scraping off rasp marks. So i wonder if that is doing the job or if there is more sound wood than I thought.
Overall I am happy with the progress but also worried. I still have at least 3 inches but preferably 5 inches to go on the tiller. You'll notice the tiller is a bit elliptical. This makes me think the original bow probably was designed for a draw length of between 28-30". You'd think if such a short bow was meant for 31-32" it would bend more in the section of a circle, more in the handle. Maybe I underestimate yew :P. I still have inches for the belly to pop and/or just have the bow blow overall because of its short length. I did burnish the back in hopes of adding some distance.
Just wanted to update everyone. Thank you for watching!
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It looks great and so does your shop. Be careful removing wood now. When I got my warbow to that point it seemed that rubbing my hand down it would cost me a pound or two.
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Glad to hear things are going well.
That's quite a wide block on your tiller and I can see it's curved but is it curved enough to not interfere with the bend?
When you draw the bow, only a 5-6cm area of your hand is resisting the pull!
If That block swivels, I'd turn it around for less surface area.
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DC: Thank you. Yeah I'm only going to remove wood for tiller faults. So hopefully none more but we'll see. I'm wanting to see what the bow on Mary Rose would've potentially hit in terms of draw weight. Yeah 1mm too much and you can totally miss your goal draw weight. I know the feeling. I bet this thing will lose 5lbs alone in set if it makes it as far as I want.
meanewood: It is a wide block but so far the wings have not come close to interfering with bend on any of my bows. I suppose a small plains bow it could be a problem. It's so big because a slightly smaller one I had before split right off and contributed to a broken bow. So, I made it chunkier and turned the grain parallel. It could probably stand to lose a little size though I agree.
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Video: https://youtu.be/D_LvEcqdu-A
Here it is drawn to 28"
Picture also of it at 28": https://imgur.com/I1yY0TZ
Shortly after I pulled it to 29". It's still in one piece! So for the sake of science at 29" it weighed 99lbs. I've only shaved off a tenth of a mm here and there to round out the tiller. So, with the one inch shorter original bow at 29" it would maybe reach 103-105lbs. It is an interesting finding to think even the smallest bow on the ship was round abouts 100lbs probably. Any tiller critiques are welcome. I think I will shoot it at 29" for a bit and then see about those last 2 inches. Do you guys think it has a chance at 31"?
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2" of extra draw is only 2/3" of actual tip movement... it probably be fine.
Del
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You can probably take the tape off now ;) Can we have a picture of the "spot" now it's done?
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In general, the further you pull a bow the more the middle wants to bend. That means if you've got an elliptical tiller a few inches less than your ideal draw length you're almost certainly safe, provided the limbs are bending well and you have no danger areas. You'll just end up with a more circular tiller.
Don't forget that smallest and shortest are two different things - there are SMALLER bows on the ship, but not SHORTER. Yours won't be the lightest by a long way, as some of them were longer and smaller, making them quite a bit less heavy. Also, using American timber will give you slightly inaccurate results and then you have to work out whether the American timber yours is made from is good, average or bad for its species and so on. That's why it's virtually impossible to pigeonhole the MR bows into a weight range. It's also why personally I prefer to always copy one specific bow when I'm making a Mary Rose replica instead of falling into the trap of making "a Mary Rose style bow" because the ever changing results are so interesting. The fact that the same dimensions applied to timber from the same tree can give me 130lb, 140lb and 180lb shows that nicely.
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Del the Cat: Thank you much. I've always wondered how much tip travel actually happened per inch of draw length. Sounds good.
DC: ;D You're probably right. I will have pics up after work tonight or tomorrow morning.
WillS: Thank you. Yeah it seems still decently elliptical at 29" so hopefully it'll manage to include the handle in the last 2"... and not blow. ;) Interesting. I did not know there were narrower bows on the ship in terms of girth. Well, just as there are drastic differences from piece to piece of English, Italian, or other European yew, I imagine there are some major discrepancies between pieces of American yew. I've seen that in action for sure. I bet there's a good deal of overlap between the two species but I agree with your point. Taxus brevifolia tends to be slightly lower in SG to Taxus bacatta. This piece in specific is by appearance very good. It has chocolate brown heartwood and an average ring count of 65-75 rpi. But in actual performance on the tree it seems to be taking set and rebounding just about the same as the two 40rpi staves I've worked with previously. Its harder to cut with a scraper than other yew I've worked but doesn't feel exceptionally more dense, but definitely not less. I know these are kind of qualitative markers and not hard numbers, but it is something. It's the best we can do versus going back in time before the wreck and using the bows before they sank :D.
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DC: https://imgur.com/Ibn0MiL and https://imgur.com/wdTVF6G Here are the pictures of the limb spot after making it to 29". I shot it at 29" yesterday and it was a wonderfully smooth shooter. I will try to get it back to 31" though because I will definitely accidentally overdraw it since I'm not used to anchoring at 29".
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That should be ok as it is near the neutral plane so neither under tension nor compression. :)
Looking good :)
Del
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Thanks for the pictures. It still makes me do a little double take. it will probably be fine but if it does break I'd bet a dollar that it breaks there. One side looks fine but the other is a bit iffy. I guess it just depends on how deep the iffy stuff goes. It could be skin deep or it could go 7/8 of the way through. It looks gorgeous and bends beautifully though. Good job!
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https://imgur.com/ejpBDPg
IT MADE IT! Boy it takes some juevos to bring a bow you're not so sure about to full draw. I pulled it to 31.5" on the tree for safety and here it is at my full 31" anchor in the hand. At 31" on the tree it weighed in at 109#. I can't wait to shoot it in and then get a finish on it. It's in the teens Fahrenheit and dry here so definitely not good self bow weather. But this weekend hopefully a shoot video will be upon us. I am very thankful to any and all of you who contributed in this thread. It is a great feeling to have the bow you envisioned in the stave make it to real life.
In regards to previous comments- DelCat: I see what you are saying. I think It would've been most scary had I reduced sap and it ended up in the tension plane. Thank you very much for your help. It shall leave a beautiful two tone effect in the bow.
DC: No problem. Imgur helps streamline it while keeping good quality pics. Yeah It's still spooky to look at and we truly can't call it a bow till its been shot through at 31" but its appearance hasn't changed at all since the beginning. Thank you very much for your advice and compliments. I'm trying to dial in the proper tiller in terms of round arc and elliptical through every bow I make. I think the fact that this one didn't blow is a show of improvement.
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Looks good :)
Most important thing in a Yew warbow is decent sapwood.
I had some wood from a log that had been lying on the ground, First Warbow blew, but it did have a big knot... second exploded.... third one, I sawed off the sapwood and glued on a strip of yew sapwood from my secret stash ;D . This one didn't blow... same heart wood, decent sapwood.
Del
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Man that must've been a tough laminating job having to get those two pieces to marry well. Yeah I enjoy a good sap heart barrier both to look at and also the feeling of reassurance it won't blow. Just got this one it tru oiled and polished so hopefully will make finished post soon. Thanks again Del.