Bowstring Again and a Visit.

I'm getting stuff together for a Tudor bowmaking re-enactment and wanted some pukka Flemish twist linen bowstrings. No body could do 'em for me in time (2 weeks) !
So I set to and made one myself, bit of a pain but it didn't take too long once I'd got the loop done. I followed the instructions in the Traditional Bowyers Bible vol2 . It was rather good when done and waxed up, felt sort of snakelike. I tried it on my 68# longbow, it had very little stretch, much better than Dacron and the bowyers knot didn't slip at all, confirming my suspicion that it's slippery modern materials that make bowyers knots slip.

About mid day I had a visit from a lovely couple. The chap, who also makes bows had contacted me, having been following the blog. They were up in this area visiting and he very kindly brought me 2 lovely Elm 1/4 logs about 7' long which had been cut at their home in Devon. Excellent! There's not much Elm about and the last stuff I had was way back when we had that outbreak of Dutch Elm disease (in the late 1960s).
We got on really well, and while us gents were shooting the bows the ladies were enjoying a chat and a cuppa in the garden. The bows all had a good work out including the Chinese repeater. It was nice that the lady joined in and had a go with my crossbow pistol and watched the Chinese repeater as sometimes it's not of much interest. They stayed for a couple of hours, but I got the feeling that if they didn't need to be on their way, we could have opened  a bottle of wine and some pizzas and made a long lazy day of it.

This blog has been great for meeting interesting people and I've made contact with some lovely people, helped people out with materials and had all sorts of materials in return. It's a wonderful give and take which would have been virtually impossible without the internet.

Meanwhile I'm busily trying to research what tools would be historically accurate in Tudor times, the problem is that tools like rasps and files existed but would probably looked less uniform than the machine made modern equivalents... (Note to self:- Remove plastic handles ;) )

Warbow Explodes

I'd rounded the belly a bit and cut second nocks so I could get a shorter string on it.
With the winch pulling the long string I had to take it to 110#  just to get the short string on at a very low brace.
I winched it back to about 70# and it looked ok. I thought I'd take it further. At 100# I heard a 'tic' the death knell of a bow (probably the back giving way).
Turn the sound up and you'll hear it, a split second later it exploded.
No point me pontificating as to why, if I have to guess I'd say the back wasn't perfect. It could even have been damaged when the up and over garage door jammed against the bow as I opened it... I neglected to check the back. Of course there are marks on the back now where it smashed into the underside of the door.
The good thing is the splice held solid and the lower limb remained in one piece.
This illustrates the point about a short string applying greater load than a long one.... I'd pulled it to 110# on the long string several times, yet it blew at just over 100# at low brace.

Checking the original videos I can see the tip deflection on the right limb with the long string was 3 bricks. On the short string it just about hits 4 bricks and then explodes.
Update:-

I've slowed down the video and there is a tiny bit of something or other that pops off from the centre of the back of the bow and flies off horizontally to the right when it goes tick, maybe it's something from the splice glue line on the back? It's certainly from the centre of the bow. You need to view it full screen.
The sound doesn't appear to be there but watch closely! (Maybe it's a UFO ?? ;) and Aliens caused it.
The video isn't hi res because it's compressed. I've studied the original and the break definitely starts at the grip. It probably is the discontinuity in the sapwood at the splice. This confirms my suspicion that a sapwood overlay over a splice is a good safety measure.
You could say I was working the bow too hard in the middle, but don't blame me! I left it slightly over size compared with the Mary Rose bow dimensions... nuffin' to do wiv me mate ;)
You can see from the stills that the crack has propagated along the length of the limb through the heartwood.
Studying the video closely I think the sapwood gives way in the centre, this removes the protection from the tension-weak heartwood which gives way and splits along the right limb, as it splits the limb flexes more and actually breaks at a second point about 2/3 of the way along that limb.
In terms of actual tip deflection it wasn't all that far from a full draw, which on a similar bow is only one more bricks worth of tip deflection.
I'm a bit disappointed, but I think the careful study of it has taught me a few lessons.
Further Update:-
I think I've found the culprit!
I reassembled the centre section and sure enough there is a sliver missing. It's not the actual join that was the problem, more the discontinuity where the sapwood has been rasped to match either side of the join, you can see the crack going from the missing sliver to the edge of the bow.
A thin sapwood overlay would probably have held it all together. Mind I couldn't overlay any sapwood because of the nice feature knot...catch 22!  c'est la vie.

A Day on the Warbow

8am:-
Filed grooves in the temporary nock overlays, tied on a rope and put the bow up on the tiller.
I winched it back to about 60#, not much movement.
Winch it back to 100#, I can see the right limb is flexing an few inches, the left is stiff. I need to work it down closer to the Mary Rose dimensions, before I can do any serious tillering.
The tips have pulled down about 1 brick on the wall (about 3 1/2") not enough movement to be worth videoing ...yet.
Note:- 100# on a loose rope is less stress on the bow than 100# with a tight braced string, due to the geometry of a tight string effectively giving you leverage.
Explanation/illustration:-
Imagine a steel wire clamped at each end taut between to walls 10 feet apart. You could pull down on the centre of the wire and get maybe half an inch of movement because you are pulling at 90 degrees to the wire. Now take the same wire and clamp one end to a solid immovable roof joist and pull straight down on the wire, you may stretch it it 1/100" but very little.

9am:-
Been over the lower limb with spokeshave and rasp measuring with vernier calipers. It's pretty much to MR (Mary Rose) dimensions +0.3mm -0
The dimensions given are from the centreline at 100, 200 400, 600, 800 & 900 mm. I spot check at those positions and blend in between them as I work it down. The wood and the spokeshave seem to like that graceful taper as some areas of pin knots which were tearing are cutting more cleanly now.
I've left the tips wide in case of stringline or twist issues. Break for tea and toast.

11am:-
Been over the upper limb and had it up on the tiller with the camera running. It's looking more like a bow now. I'll clean it up, round the belly a bit and check over the back.
Then it will be a matter of trying to get it braced... note use of word 'trying' it will be a bit of a struggle.

Hidden Knot

As I feared, the 'good ' knot soon turned into manky wood as I rasped down towards the required thickness. Note 'rasped' rather than used the spokeshave which I'd been using elsewhere. The wood round knots will snag and tear with a drawknife, spokeshave or plane, so a rasp is required. The needle file has been ground to a chisel point for digging out knots, the tape marks the depth of the hole.


The good thing is it doesn't penetrate into the sapwood or come out the side of the bow. I cleaned it right out down to good sound wood and filled it with epoxy and wood dust mix. I may peg it later as a cosmetic measure, but it's good to leave the natural flow of the wood rather than drilling an over sized round hole and pegging.
I recently saw a Yew warbow with some nasty pinches where knots hadn't been pegged and the narrow black line of manky stuff round the knot had compressed allowing the pinch. One knot had been pegged but the smaller ones missed... classic case of "spoiling the ship for a ha'p'orth of tar".

Here's a pic of the back too, work in progress, I'm slowly (and loosely)  following a growth ring from left to right you can see the lines of the rings running roughly along the limb. As the bow progresses this will get further tidied until it is fairly close to a single ring, or a series of rings running along the length.

The upper limb is about to dimension now, I've got to go over the lower one and get it a bit closer before I put it on the tiller.
I've glued on some wedges of Yew (offcuts from the splicing) to cut in temporary knocks. I'll just lash it with rope for the first try on the tiller, but I don't want to rush into it today.
Instead I got my wife to put one foot on the middle of the bow, one tip was on the floor while I held the other tip about 6" off the floor. She just about put all her weight on it making it flex nicely and the splice held firm.
I had asked what she weighed, but I was told a gentleman doesn't ask!
Good progress, but I won't spoil it by rushing.



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Whew What a Scorcher

Summer has finally arrived. I got lift up the club and gave the Yew Stickbow a try out, it pretty much did the job and would certainly have made an effective hunting weapon. It's a testament to the properties of Yew.
The field had been mowed and there were big bales of hay, we lobbed a few arrow at them clout style. It was a relief to get into the woods where it was much cooler and to shoot at the 2D animal target faces.

I've spent a fair bit of time on the Warbow tidying up the back approximately to a single growth ring, and one limb is about roughed out to dimensions. It does flex very slightly if I lean on it.
I'm not being over fussy at this stage. The rings don't run concentric to the curve of the back anyway, so there will be places where the rings show as lines running down the length of the bow.
I'm pretty much going to follow the dimensions from Weapons of Warre but keeping a very square section initially, then I'll put it up on the tiller and see what it does.
I'll probably add temporary tip overlays, maybe slivers of horn to protect the back at the nocks. I'll winch it back to a decent poundage before worrying about rounding it off.
There is one knot on the belly that doesn't go too deep, but is manky round it's core so I've dug it out and will peg it.
More worrying is what looks like very sound knot on the belly with an associated bulge on the back and a red/purple blush on the side, maybe there is rot lurking under there? The red blush can be a sign of hidden trouble.

Warbow Splice

The splice has come out well, I've cleaned it up and I've looked through 'Weapons of Warre' to find a suitable bow to use as a reference. I've found Mary Rose bow 81A3960H which is described as "Big bow, handled, broken tip, squared, coarse grain " Being gripped and squared means it's pretty chunky in the middle which will give extra strength at the splice. Of course I won't copy the broken tip ;) . Its 2005 mm long.
The first pic shows it marked up and how one billet has been glued to an offcut of MDF to give it a flat stable base to help when running it through the bandsaw. The otherbillet had a nice flat face already. Last pic on the bottom right shows how the heart/sap boundary has lined up well, I'd llike to say this was carefull planning, but there is a fair bit of luck involved it trying to line everything up.

In the morning Paul who I'd met on the Archery Interchange website came over to try some bows. It was great to see a recurve target archer having a go at shooting primitive. I think it's good to try the different disciplines although I'm slightly abashed to admit I've not shot a sighted recurve. Mind this could be due to never having been offered a go with one, as I'll give anything a try. We had a fine time and gave the Chinese Repeater an outing to. Paul left with a Maple primitive which had been looking for a home and a few arrows.


I also heard that the Dogleg Yew longbow was throwing full weight medieval arrows all the way to the 180 yard clout, much to the delight of it's new owner.

Knots in Yew

I've been sorting through my seasoned staves and billets, I had one great fat knobbly Yew stave which might make a character warbow, but it had a huge ugly knot on the belly near one tip. If I cut the tip off it would be a bit short.
I decided to lop off that limb and use the good limb with another billet to make a spliced warbow.
Out of interest I sliced through the knot on the bandsaw, it shows how much rot can be hidden beneath a tiny pin on the sapwood.
Conversely I also sliced through one of the big knobbly features and found lovely sound wood!

 I've marked out the splice and got it glued and clamped. I'll see how it looks in the morning.

In the pic with the knobbly bit cut through there are attractive streaks in the wood radiating up into the knobbly bit. There's also a big knot going through it on the diagonal. I was pleasantly surprised that the knobby bit was sound and I've left one on the good limb which will sit just above the grip on the finished bow. I've done a 2 pronged Z splice this time rather than a simple V. More pics in a new post tomorrow.