Black Walnut Chrysals - Fatal or Not?

[barebo]

I had a fellow give me a kiln dried 1x6 Black Walnut board and he asked me to build him a bow. I made one in 2010 from a stave that turned out great so I said "Sure". I knew this would need a backing and found a great source for quarter sawn Hickory backing strips at "Lumberman. Com" and glued the 1/8" strip on and got a perfect glue line. I spent a long time carefully shaving and bending on the long string and once braced felt I would be good to go. I trapped the hickory just over 1/4" and rounded the edges of the limbs and got a nice profile feeling pretty good.
I took it out and shot about 40 arrows and was really pleased with the way it shot.
I finish sanded down to 220 and wiped on Tru Oil and put a nice leather shelf / strike plate on and was going to shoot it one more time before giving it to the new owner. I braced it and walked outside and was going to admire my work and got a shock - chrysals just beyond the fade on the lower limb. About 4-5" above is a pin knot and the wood in that area was harder to work and I have to wonder if that was the culprit - too stiff there making the chrysaled area work harder?
My question is this: do those tiny cracks go deep into the limb? I'm at about 53# and am considering sanding the finish from the belly of both limbs and re-tillering? I can drop 7 or 8 # draw weight and there is no issue there. I tried to post pics of the bow but they're too big.
It is 70" NTN and 1-7/16" wide tapering to 1/2" nocks - Comstock profile.

[PatM]

They go deep and they'll just keep going deeper if you reduce it.

[bassman]

I have made a fair share of Walnut sapling bows. Clean wood with no knots. I had only one fret on the belly, but it was because I burned the belly in that spot well getting carried away while heat treating. Never had the back let go on any of them, but I can't speak to a Walnut board bow other than your Hickory back over powered your Walnut belly. That would be my best guess.. My bows ranged from 56 to 62 inches long, and 40 to 45 lbs at 25 to 26 inch draw, and straight taper from fades to tips. Belly heat treating is important with that wood as well as many other woods.

[barebo]

Hopefully these aren't too small to show the chrysals.  So Pat B, do you think it's a lost cause?

[barebo]

I do think that the Hickory may have overpowered the Walnut. I had it tillered to a nice even bend - the pic on my target butt makes the outer limbs appear stiff but they come round nicely.
It shoots great - lot of work for a possible bust!

Bassman, I've made quite a few stave bows and have heat treated the belly on a few but this one didn't seem to need any help in zipping arrows down range. I don't think having a backing on with Titebond 3 wouldn't lend itself to the heat gun? Plain wood staves have never chrysalled on me and the bamboo backed Ipe and others didn't as well. Walnut in kiln dried board form is tricky.
I wish I'd shot it more before giving it a finish.

[bownarra]

You would have to lose a lot of weight and not touch that area at all. Even then the wood in that area is already damaged beyond repair.
I've made a few hickory backed b.walnut bows and the combo is possible but not ideal. If you were to use b.walnut belly again I'd recommend some maple for the backing.
No you shouldn't heat htreat a lam bow. You can heat treat the belly lam pre-glueup.
Your fades are weak if it chrysaled there. It also looks thin on one side. A chrysal only occurs when at area is working too hard. Normally the wood just tipward is stiff too.

[barebo]

The fade transition is pretty good - it only just starts to work about 3/4 drawn. I thought that 1/8" backing trapped on the back wouldn't be too much but maybe should have thinned it or trapped it more than I did. That pin knot had me concerned and I believe I left too much material around it forcing the area to take too much of the bend load. Outer limbs could have bent a tad more as well. I don't know if I want to attempt another Walnut cored bow but it's going to be a long winter.

[barebo]

Here is the Black Walnut longbow I made from a stave in 2010. I chased 5 rings and it took a long while but made a nice bow.

[simk]

barebo, heat treating a lam bow is usually not recommended.
still: I was in the same situation - where you've got nothing to loose - more than once and nonetheless tried it. I heat treated sinew backed bows and lam bows glued with epoxy and fishglue. it worked and saved my bows.
I just tried to prevent the heat from penetrating too deep; set the heatgun really hot and put it close while moving over the spot. don't heat too long. probably thickness of belly lam also matters.
it's a gamble, but when you've got nothing to loose...
I've got no experience with titebond.

EDIT: ...and as long as tiller didn't change and you do not see a hinge from the chrysals I wouldn't do anything. these fine ones look superficial to me.
EDIT2: what you can off course do is slightly retiller and try to relieve stress from that particular spot....

[barebo]

That was my thought as well. If I did retiller and reduce the overall strain on the limbs it might survive for a while. When I trimmed the 1/4 strips from each side of the Hickory backing to match the Walnut core profile, i was amazed at how tough the quarter sawn Hickory was even in that narrow strip. I'm not afraid of the bow "blowing up" on me as even if the belly fails it will likely just fold at the spot where the issue is. What I should have done is selected a board rather than to take the first one that the fellow slid off the top of the stack of several beautiful Walnut boards. I likely could have found one with grain oriented in a better pattern.

[bassman]

Nice bow  above. Sapling Walnut have thick  rings right under the bark that I have a lot of confidence in as far as breaking ,and deep heat treating the belly seems to balance things out. It  is soft hard wood like Birch, so I don't know how long either Walnut, or Birch would last under hard use as a bow, but it is fun playing around with it just to see what you can get out of them. I have tried my hand at lam bows. Bamboo backed bamboo, Hickory backed Hickory, etc. every one knows what I am about to say. Bamboo backed Osage,and Bamboo backed Ipe are pretty hard to beat as a lam bow. I have come full circle,and just sinew back them now if I want a backing.

[bownarra]

Once wood is chrysaled its toast Simple It can only get worse and will eventually. I'm not saying you can't shoot it some but you can not make a silk purse out of a sows ear Years ago I used to try and 'fix' things and have tried most things. Don't waste your time trying to 'fix' it. That's experience talking However you can gain your own experience by trying....six and 2 threes but my opinion is what it is because I've been there and got that hat.
 

[barebo]

I'm with you on the not trying to fix it statement. I knew initially it was the proverbial "lost cause" but thought there was a glimmer of hope that someone here had a miracle cure for chrysals!
This was number 80 or 81 for me and I think fourth or fifth failure including 2 that actually broke at draw - it happens with natural materials.

I don't have the facility to do fiberglass bows and have owned a Lot of them since starting in Traditional archery in 1970. I don't have to explain the allure of making a bow with hand tools and a piece of wood that ends up a viable hunting or recreational tool. Here in central NY state we don't have Osage (I wish!) but trees for a million lifetimes of self bow or laminated bow pursuits.
Hard to quit this addiction!

Thanks to all for the input.

[bradsmith2010]

this may have been mentioned, grind the belly off and replace,, Miracle Cure,,

[barebo]

When I ripped the 1x6 (almost 7" actual)on my table saw into 3 even width slats, the 2 outside curved into bananas. The center stayed straight. I went out this morning with a string and marked off one of those with the least curve and proceeded to bandsaw a fairly decent and straight core. Upon looking it over I find a knot right on the edge that would be in the middle of the working limb no matter top or bottom. That just plain sucked. I have the other one but am too frustrated to try to cut another core from it today. I ain't a quitter!