I tested some Lemonwood today.

[yeoman]

Daryl (Greybeard) has recently come into some Lemonwood, and he was kind enough to send me some samples to subject to bend tests.

I first read of Lemonwood when I was about 14, and just starting to make bows. I'd read about it in Adrian Elliot-Hodgkin's 'The Archer's Craft', and I spent some considerable time looking for it, only to be met with uniform quizzical looks from even the most experienced woodworkers.

I thought the days of Lemonwood were long gone, and that I would never get to work with it.

And now I've broken some. But it was all in the name of science, I promise.

I'd read that bowyers made their bows with reckless abandon, caring nary a bit about the grain, which was almost impossible to make out in any case. I didn't know how this could be possible but seeing it now, they were all right. The grain is extraordinarily difficult to determine.

The test was a setup much like Tim Baker's in TBB vol.I, except the spreadsheet I use can accommodate different widths and thicknesses.

The wood eventually failed with an almighty bang right at the fulcrum, and the nature of the fracture looked to me to be a classic 'too-dry' fracture, as the sample took very little set (6.25% of deflection) before breaking, and there was little to no splintering of fibers. I think this would qualify for a 'brittle' description. However, do not think this makes it unsuitable for bows. It just means the wood doesn't take much set before failing (with vigor).

MoE: 15,921 MPa
This places it just above the range of results of other testing (10,000 - 14,688 MPa). Compared to other woods, its stiffness is similar to Birch, Osage, Maple and Ash.

Working stress*: 120 MPa
This bending stress means the working strain should be 0.75% to deliver a bow that has a safe bending stress, and has a set of about 6.7% of the deflection.
*Now, the sample withstood 130 MPa bravely, at 80 mm deflection. However the fact that it came asunder at 90 mm means I'd want to ratchet the bending stress in a bow back just a little bit to that observed at 70 mm deflection, which was 120 MPa.

Thus, the Bow Wood Merit Figure is 75.15921
(this is to be interpreted as: the working strain should be 0.75%, and the stiffness is 15,921 MPa.)

To put these numbers in real-world terms, the below dimensions should make a 66" long, perfectly rectangular cross-sectioned longbow about 50 lb at 28". I removed many of the measurements to save space. It's for illustrative purposes only, and dimensions are given in mm:

distance from tip/thickness/width
0 /8 /8
250 /11 /24
480 /14 /28
840 /16 /32

Daryl, if you want to test the hypothesis, I can send a more detailed layout to see how far off I am.

My plan is to leave the other samples for a week or two to see if adjusting to the local climate makes a difference to the results.

That is all for the evening.

[greybeard]

Dave, thank you for conducting the bending tests on the Degame.

Degame Compliation.jpg (154.19 KiB) Viewed 2473 times

We may have to take into consideration that the timber was reclaimed from pallet bases and as such may have been substandard/reject timber.

The timber with its fine grain was good to work with and sanding was easier than most timbers I have used.

My test bow appeared to come out substantially under weight [34-22 lb@28”] when compared to hickory or hard rock maple.

The bow is 68” n to n and dimensions were taken starting at inside the tip overlay; width - 14.3mm, depth - 10mm, 305mm from tip, width - 25mm, depth 11.4mm, 610 mm from tip, width - 35mm, depth - 13.5mm. I was impossible to pick the exact spot where the fades transitioned into the limbs.

Grain etc must have been fairly consistent as the limb profile was obtained using vernier callipers and I ended up with 1/8” positive tiller.

Degame Flatbow Braced.JPG (43.3 KiB) Viewed 2473 times

I think it will be worth buying a plank when their stock arrives in the New Year. Price for 140 x 45 mm is expected to be about $23.00 per linear metre.

Daryl.

[Nezwin]

Daryl,

Would you use the pallet bases again or would you just wait for the milled boards in February? Also, was your test bow a selfbow or backed? It wouldn't appear to be backed from the images.

Neil

[yeoman]

The pleasure's all mine Daryl. Happy to repeat for any other samples you may have. Actually I'd be interested in trying some Red Ash if ever you come by any.

Was that bow made from the same piece of wood that yeilded any of the test pieces? For those reading along at home, Daryl sent me nine samples. Two from one board and seven from another.

How much set did it take? Going by your thickness measurements, if you'd made it roughly 10% thicker, the draw weight would've come up to 30 lb, and increasing the width to 40 mm would have brought it up again to 34 lb at 28".

In your first three pictures, the grain is much clearer 'ín the rough' than it is in person on clean wood. At it looks reasonably wavy too. Did the bow come out of any of those first three boards?

$23 is a tantalising price for a wood that I thought would never in my life be available. Especially for the size of the boards they're getting!

Dave

[greybeard]

Would you use the pallet bases again or would you just wait for the milled boards in February? Also, was your test bow a selfbow or backed? It wouldn't appear to be backed from the images.

Neil, I will but only for experimental purposes such as bow design. Once a design is proven I will use 'new' timber. No the stave is not backed but I am planning a bamboo backed 'D' section longbow to see how the timber handles compression.

Was that bow made from the same piece of wood that yeilded any of the test pieces? For those reading along at home, Daryl sent me nine samples. Two from one board and seven from another.....How much set did it take?

Dave, The bow was from the same timber as the two red samples. The bow has had less than a dozen arrows through it but at the moment set is about 6mm.

Also I am a bit confused by the following;

Going by your thickness measurements, if you'd made it roughly 10% thicker, the draw weight would've come up to 30 lb, and increasing the width to 40 mm would have brought it up again to 34 lb at 28".

The bow weighed out at 34.22# @ 28".

.....My test bow appeared to come out substantially under weight [34-22 lb@28”] when compared to hickory or hard rock maple..

In your first three pictures, the grain is much clearer 'ín the rough' than it is in person on clean wood. At it looks reasonably wavy too. Did the bow come out of any of those first three boards?

No, I had started making the bow before I remembered to take photos.

Daryl.

[yeoman]

Sorry, I misinterpreted your post. I thought you meant what had been 34# in Maple was only 22 # in Lemonwood.

Dave

[Nezwin]

the stave is not backed

Thanks, Daryl. I had read Lemonwood was so popular in previous decades due to the tight grain structure which allowed for it to be very forgiving when unbacked. It also supports the comment by a colleague who works almost exclusively with Pacific Yew who commented that Lemonwood reminded him of the white sapwood of Yew, particularly the forgiving & tight grain.

[hardgainer]

Apologies..... not a tech contributor but to see lemonwood in discussion sure brings back memories.
My mother bought me my first lemonwood bow in 1947 make not recalled