chrysal fix?

[upstatenybowyer]

Some of you may have seen one of my recent posts, "there's a hole in my belly." Well, the bow is tillered out, shooting amazing, and as I'm applying finish, I notice this small chrysal just above the hole that I filled with CA. I'm referring to the line just above the hole on the left. There's a clamp mark a little higher on the right, and that is not a chrysal. Any fix ideas? I thought about wrapping over the hole and chrysal with sinew or, gluing a very thin lam of horn over it and then wrapping. I really don't want to loose this bow! Thoughts?

[bradsmith2010]

could we see the bow at full draw,, whats the clamp mark from,, did the crysal come from clamping or shooting,,

[upstatenybowyer]

full draw

sorry about the stupid look on my face

I had the bow clamped over the glue-filled hole while I heat treated a little bit of reflex into the mid-limb. I didn't notice the chyrsal until after I shot it a bit.

[upstatenybowyer]

and here's a shot of the belly so you can see where the glue filled hole is (just below the handle)

the wood is HHB

[Wooden Spring]

You can always give the bow a trapezoid cross section by narrowing the back by about 10-15% of the belly width. Most woods are stronger in tension than they are in compression, this will help even the forces.

[BowEd]

upstate....Right now I'm sure it is'nt showing anything in change of tiller or anything.The bow looks fine.How much shooting has it done?It has'nt migrated across to the edges of your limb.If and when it does that your tiller will change then.Pretty much end of story then too.Those chrysals are a kind of use it wait and see kind of thing,but in time with more and more use they seem to get worse.There is a possibility yours won't.No way to say this all kindly.I've seen these things not develop more or get worse even after 2000 shots but eventually they did.If the bow is not a stressful design with good length and width it could last a very long time.
Now I have seen but not done people who have taken a section of wood out and replaced it matching surfaces perfectly.The people who have done that could comment.If you're really wanting to try to save the bow that's what I would do.
PS....You know using buffered pads of wood will eliminate those clamp marks.

[upstatenybowyer]

Bead, thanks for the reply. I decided to take a file to it and low and behold, it disappeared! It must have been very shallow. There are no other chrysals on the entire belly so I think I'm in the clear (fingers crossed). I've got some finishing touches in mind so I guess I'll get to it and post the bow when it's done. Thanks again.

[Dakota Kid]

I wonder if the superglue was too hard of a substance to fill a hole of that size. I doubt superglue compresses the way a good bow wood does. It may crush the wood above and below, kind of like closing a door with a stone stuck in the jam. I use TB mixed with powdered antler or sawdust. It seems to be a little softer/ squishier than superglue.

[mullet]

Why are you pulling it back so far? It's not a Compound Bow.

[Jim Davis]

Why are you pulling it back so far? It's not a Compound Bow.

+1

And, the lower limb seems to be bending more than the upper...

If you ever do need to repair a chrysal, there are ways to do it.

[aaron]

I hope this bow survives- either way, it's a great teaching bow. Generally, a chrysal is caused by wood bending too much and failing in compression. If the chrysal is not too advanced, you can sometimes halt it's progress by fixing the problem. The problem is too much bend. To make it bend less, add wood to the area or remove wood everywhere else. heat treating may also be an option. I also wonder why you're pulling it to your ear- was it designed to do that? If not, a few extra inches of draw like that will cause unnececary set (or even chrysalis). Sanding or filing away a chrysal seems like the opposite of what would work.

[mikekeswick]

Unfortunately there is no real fix for chrysals. A chrysal happens because the wood has been crushed, the amount of compression on that spot was too great for the woods ability to resist it. Its like a person lifting a weight that is too heavy for them and tearing a muscle. Sure you can put a bandage on it but that doesn't mean the muscle is fixed...fortunately we heal but wood doesn't. Once you have taken it past its limits that is it done. In my opinion its a waste of time trying to fix it. I only say that now because I have tried all the different methods to 'fix' them. I've done Dean Torges scoop method and whilst they do hold well it is not ideal. The butt joint method is worth trying for the experience but a butt joint in a working limb will open a little over time.
Best fix for a chrysal.....start again

[mikekeswick]

And for future staves with knots like this you should have left extra width around that area when shaping the width. Say that knot is 1/2 inch across, there should have been an extra 1/2 inch width at that area. This would have meant that that area had the same amount of clean wood to do the work instead of as it is now with no added width.
Imagine the grain of wood being like water in a stream. Grain flows around knots like water flows around a rock.  You can see this in your picture.

[upstatenybowyer]

Thanks for all the input folks. This has definitely been a great learning bow.

It was designed to pull further than my draw length, as it was intended to be a Christmas gift for my brother-in-law (he has a 30" draw length).

Mike, I think you're right about there being no real good fix for chrysals. I'm hoping I got lucky with this one, as it only took 2 or 3 strokes with a file to remove it. Going forward I will definitely leave extra width around spots with holes such as this one. There are still so many things I don't know about making bows.

Asharrow, the picture does make it look like the bottom limb is bending more. It may be the camera angle, as it does not appear that way on the tillering tree with the bow resting horizontally.

[BowEd]

upstate....That's great you were able to file it away.That can happen too.The way I check that for sure is to put a little laguer on the area and it will show if there is a crack.I used to use saliva but laquer dries up quicker.