BL Mohegan (No. 60) and Algonkin (No.61)

[simson]

Well, was a while since I was here, got some health problems.

I've got a nice bl stave from my good friend Marc to make him a short recurve. The stave is about 1½” thick and 1¼” wide, clean free of knots and with a nice relative even reflex. Some sap layers are on and has a really nice color. Length is 66”








As Marc is now 78 years old he wants a bow 30-40#. This made me think over not to waste that good wood. That stave has two bows in it. I split it from the middle outwards to the tips. Everything went o.k. , I just lost one or two rings for the split.










Next step chasing ring on the belly split and working down the back split to the fat ring. I will leave the sap on because the nice look.

8




Now look what I've got! The back split is upwards the belly split downwards.

Why the hell has the back split more reflex than the belly split? Because of the sap? Is sap more tension strong than heart wood? I've read the opposite. I haven't worked much with BL so far, can anyone explain? BL profs please chime in, have you ever noticed something like this?




Here are two pics of the cleaned staves






And here already the back split with evened out reflex (heatgun), and the belly split cut to 52” and steamed in recurves. I will try to make a Mohegan recurve for Marc and a Algonkin  bow from the back split. (Source will be 'Encyclopedia of american native bows, arrows and quivers' from Hamm / Allely).

[blackhawk]

Wood can do funny things eh when ya relieve them from the different stresses within a tree. I don't know for certainty but my guess is that as the tree got bigger it had to hold more tension and weight hence why the top split pulled in more reflex. As a tree grows the stresses upon it change,and it can be different from a belly split to a top split etc etc...and tension and compression sides as well etc...who knows maybe it was growing more straight up and as it got bigger and had more weight a wind event or something caused it to lean even more causing the tension side to become stronger than what was grown before it. Now that outer wood is having to hold more than what was before it when it was younger.

[DC]

Is it possible that the sapwood shrinks more when it dries pulling the outside piece into reflex? Don't know if that would necessarily mean that it's tension strong. I have't worked BL yet but I've got a couple drying.

[gutpile]

more guts than me..I wouldn't of split it in two...1 1/4 is mighty thin width for a BL bow... its not osage and is gonna take some set at that width ..but I guess at 30 to 40 lbs it should hold well..good luck..gut

[Carson (CMB)]

more guts than gutpile! That about sums up that split 

I like blackhawk's assessment. Makes sense to me.

[huisme]

The other Marc, right?

more guts than me..I wouldn't of split it in two...1 1/4 is mighty thin width for a BL bow... its not osage and is gonna take some set at that width ..but I guess at 30 to 40 lbs it should hold well..good luck..gut

http://www.primitivearcher.com/smf/index.php/topic,49241.msg672094.html#msg672094

 

Wood can do funny things eh when ya relieve them from the different stresses within a tree. I don't know for certainty but my guess is that as the tree got bigger it had to hold more tension and weight hence why the top split pulled in more reflex. As a tree grows the stresses upon it change,and it can be different from a belly split to a top split etc etc...and tension and compression sides as well etc...who knows maybe it was growing more straight up and as it got bigger and had more weight a wind event or something caused it to lean even more causing the tension side to become stronger than what was grown before it. Now that outer wood is having to hold more than what was before it when it was younger.

If I split a straight stave of locust and want to keep it that way I remove the sapwood immediately. I noticed that the sapwood shrinks more when I removed the sapwood from a couple staves and left it on others from the same section of straight trunk. The staves without sapwood pulled into maybe an inch of reflex but the staves with sapwood took ridiculous reflex ranging from three to five inches. This is due to the sapwoods harsher shrinkage, not tension strength.

All that being said it looks like you've chased down to one of the deeper sap rings, correct? That's very good as the outermost sapwood is not as tension strong as the heartwood and will slow the bow down as well as making it less resistant to rot.

[blackhawk]

If sapwood shrinks faster than the rest of the wood it'll check. And I'm assuming this piece is near proper mc and ready to bend. If that's the case then theres not enough moisture loss to cause reflex due to moisture loss. And this happened immediately I assume as well, and not over a few days or more losing moisture.

I can count on quite a few occasions when I've removed belly wood or a belly split from proper mc ready to bend wood to see it reflex almost instantly. And some of them was wood 15-30+ years old seasoned. There's proven stresses in trees that can be released in ways that can cause it to move,and has nothing to do with moisture loss issues.

[huisme]

If sapwood shrinks faster than the rest of the wood it'll check. And I'm assuming this piece is near proper mc and ready to bend. If that's the case then theres not enough moisture loss to cause reflex due to moisture loss. And this happened immediately I assume as well, and not over a few days or more losing moisture.

I can count on quite a few occasions when I've removed belly wood or a belly split from proper mc ready to bend wood to see it reflex almost instantly. And some of them was wood 15-30+ years old seasoned. There's proven stresses in trees that can be released in ways that can cause it to move,and has nothing to do with moisture loss issues.

I'm not saying that doesn't happen, a belly split from just last week kept its shape while the rest of the stave with the sapwood removed took additional reflex. However when I split the belly from a stave with sapwood I expect the back half to take significantly more reflex than if the sapwood were removed. Locust sapwood does check significantly easier than locust hardwood in my experience; in western Washington I expect bare sapwood to check into the first two or so rings of heartwood but leave chased rings unsealed no problem. When I get a clean split of sapwood off the back of a locust stave it pulls into more of a C shape than a parentheses.

[simson]

Thanks all for input! Some interesting statements.

Wood can do funny things eh when ya relieve them from the different stresses within a tree. I don't know for certainty but my guess is that as the tree got bigger it had to hold more tension and weight hence why the top split pulled in more reflex. As a tree grows the stresses upon it change,and it can be different from a belly split to a top split etc etc...and tension and compression sides as well etc...who knows maybe it was growing more straight up and as it got bigger and had more weight a wind event or something caused it to lean even more causing the tension side to become stronger than what was grown before it. Now that outer wood is having to hold more than what was before it when it was younger.

That makes definitely sense, Chris. But if true, all back/belly splits should have that different reflex. I didn't notice that in the past, but will watch in future if so.

more guts than me..I wouldn't of split it in two...1 1/4 is mighty thin width for a BL bow... its not osage and is gonna take some set at that width ..but I guess at 30 to 40 lbs it should hold well..good luck..gut

I'm already working on both, it's fine so far. Have some problems with string alignment and did a lot of heat corrections. Mohegan recurve nearly finished and algonkin comes along quite nice. Have more some enough wood.

If sapwood shrinks faster than the rest of the wood it'll check. And I'm assuming this piece is near proper mc and ready to bend. If that's the case then theres not enough moisture loss to cause reflex due to moisture loss. And this happened immediately I assume as well, and not over a few days or more losing moisture.

I can count on quite a few occasions when I've removed belly wood or a belly split from proper mc ready to bend wood to see it reflex almost instantly. And some of them was wood 15-30+ years old seasoned. There's proven stresses in trees that can be released in ways that can cause it to move,and has nothing to do with moisture loss issues.

I'm not saying that doesn't happen, a belly split from just last week kept its shape while the rest of the stave with the sapwood removed took additional reflex. However when I split the belly from a stave with sapwood I expect the back half to take significantly more reflex than if the sapwood were removed. Locust sapwood does check significantly easier than locust hardwood in my experience; in western Washington I expect bare sapwood to check into the first two or so rings of heartwood but leave chased rings unsealed no problem. When I get a clean split of sapwood off the back of a locust stave it pulls into more of a C shape than a parentheses.

Is that a proofed thing that BL sap is not as tension strong as heart wood? In my case is doesn't seem so, have nearly no set so far on the long bow.

BTW. the stave is very well seasoned  - no mc problems.

[GlisGlis]

I just finished a black locust with hardwood and sapwood for my pellet-bow tests. First time i try BL sapwood.
The rings where pretty fats so I ended with half sapwood ring ( paper backed) and approx one and a half heartwood ring.
Despite a great difference in the feeling of the two woods the bow shoots really well.
Not less effective than others all heartwood BL bows.
I think I'll use again BL sapwood in my bows

[huisme]

Is that a proofed thing that BL sap is not as tension strong as heart wood? In my case is doesn't seem so, have nearly no set so far on the long bow.

It's more prone to tension failure. I've had pristine sapwood backs fail for no apparent reason (not oven rot which is a risk with locust sapwood, especially from dying trees) where I've overlooked cut pin knots in finished bows. Locust sapwood is considerably less tolerant to climate change, never completely drying out here in my swampy neighborhood. Locust sapwood can deteriorate under the finish and fail due to rot if tension isn't too much, leading to a delamination and possibly a good smack in the face. After chasing rings on some ~120 locust staves I have not once encountered locust sapwood anywhere near as dense and hard as the heartwood. I can't confirm a consistent difference in set between sap/heartwood backed locust, but a heartwood molle shoots significantly faster than a similar sapwood backed molle.

I have made both and had them work for a long time. My first had sapwood and failed after a year of being severely overdrawn (50" ntn, 9" stiff grip, drawn to 26" most of the time but occasionally closer to 28") and had only taken four inches of set through it all. It can work, but so can douglas fir or ponderosa pine.

Edit: Oh, and heavy sapwood backed locust needs overlays or a B50 string *spits on ground* where I've made bows up to 55# with no need for overlays. The sapwood is too soft.

[simson]

Here is Marc's mohegan
it's about 40#, measurements follows exact Hamm/Allely encyclopedia

[half eye]

Excellent little bow right there sir !!!!! Very graceful to my eye. Curious as to your thoughts on performance? My experience with these types of bows is that they are pretty efficient. Anyway, very nicely done Simon
rich

[huisme]

I just made a new tip-flipper jig but the few I've made similar to that have been great performers and felt great in the hand. I need to do one for myself.

[ajooter]

Great curves and I'm sure the new owner I'd happy!!! What did you use to make those tips that nice red color?