Sinewed maple bow in trouble but saved going on 2000 arrows through...pics added

[BowEd]

Hello fellas....I recently tillered a 6 week old sinewed  60" maple bow to my draw weight of 52#@ 28".Kept in the house the whole time.The next morning I braced it again and noticed a slight flat spot in one of the limbs.It was a bit touchy tillering with wood removal on this one so I just removed wood with sand paper on a block of wood.I braced it again and excersized it to reaveal tiller and noticed a small diagonal compression fissure 3/8" long show itself at the base of the flat spot in the working portion of the limb.The tiller held good though.I immediately unbraced it.Now I have a question about something that I think might work to fix or bandade this bow.On the sinew side of bow there are small fissures crosswise too which to me is'nt unusual as I've seen them on other bows I've sinewed that are good too.I have two laminations of horn the length and width of the working portion of this bow that are approximately 3/32" thick I can put on this bow.Do you think I have a good chance of fixing this that way?Changing neutral plane etc.Oh I started with 7 and 1/2" reflex and now have 5 and 1/2" reflex.

[BowEd]

Was'nt there someone in the past I can't remember who that fixed a bow putting laminations on the belly of a compression fractured limb?I thought sanding the compression fracture away then glueing the lamination to the belly.

[PaleoNinja]

That would probably work, but horn is very heavy and very flexible so unless your bow has very extreme recurves or a set back handle, you'll just be waisting the horn and actually diminishing the performance of your bow.

[Slackbunny]

In my experience once maple starts to go in one spot, it just keeps right on a-going. I can't say for sure without actually handling the bow myself and looking at it with my own eyes, but I'd guess that its just about done for. 

[PEARL DRUMS]

I would thin that maple right down to 1/4 at the center down to 1/8" at the tips. Then add an 1/8" thick osage belly lam. Sinew and maple isnt the best marriage of strengths.

[BowEd]

Well fellas what I did was removed wood evenly from both limbs till the compression check disappeared.Then glued on 3/32" thick horn on just the working portion of the wood.Then side tillered and belly tillerd it to 53#@27".It's working fine.The nice thing about it it's got 6 and 1/4" resting reflex with the arrow getting 5" of it.It also only weighs 15.65 ounces.Seems like it worked for me.

[BowEd]

Well the bow is still alive and kicking the arrows very good.No change of tiller.Knock on wood.At least a 100 arrows so far with it being braced over 3 hours at a time.I put birch bark on it which increased the mass weight a bit to 16.1 ounce.I know it can seem silly weighing these bows but it really does slow me down while tillering.Checking set in between wood or horn removal and all.I figure if I'm gonna stick the time in to make these bows might as well make sure in my mind that it's the best I can do it.Took me four 3 hour sessions of tillering to get it to my draw weight of mid 50's @ 28".No pics but I started with 7 and 1/2" reflex and finished with 6" resting with 4 and 3/4" to 5" getting to the arrow.I'll take my fun as long as it lasts.

[Pappy]

Congrats on the repair,I would have thought it was done for. Looking forward to seeing if finished up.
   Pappy

[BowEd]

Thanks Pap.I'll have to get over to iowabo's place [about 3 hours away] and have him take a few pictures of it.If he is'nt buried in from this slow moving snow storm lately.Going on more than 24 hours of continual snowing here.

[MWirwicki]

Beadman: 
Was the maple tree cut 6 weeks prior to building the bow?  If yes, 6 weeks is not near enough time for seasoning.  Likely the reason for the initial tiller change on that next morning. 

The fissures on the sinew side are indications of either being a bit heavy on the hide glue which will crack when braced or you may have tension failures in the maple beneath the sinew, which is working the sinew to its limits. 

Starting out with 7-1/2" of reflex is quite a feet for maple, in my opinion.  Unless the original intent was for a horn/maple/sinew composite.  Good on ya though, for still getting 52# on it.  Only losing 2 inches isn't too bad either.  How many layers of sinew did you apply?  Also, how thick is your maple.  If you belly lam it with horn, then your maple becomes the core wood.  I suspect you would increase the draw weight considerably.  Also, I would wait a few months to allow the maple to season.  Frets, fissures or crysaling on the belly are permanent.  Any time I have ever tried to remedy a fret, they've always come back.  If you decided to belly lam, keep in mind you would still have "damaged" wood beneath it. 

Congrats on saving the bow though.   I just wanted to comment on your original post, as something to consider on future projects.

[BowEd]

Matt the maple stave was 8 years old.It was not intended for horn in the beginning.I did one earlier with that intention and wanted to see the difference in performance knowing without the horn it would weigh less.The earlier one was out of hickory though which probably is'nt fair to old hick put I did it anyway.I don't over use glue when I sinew but enough to thoroughly soak my pre soaked sinew before applying.It's got about 1/8" dried sinew on its' back.Two sessions.The last session was buffalo backstrap the full length of the limbs.I would say about 275 grains per foot total on the limbs.The horn did increase the poundage of course but I removed enough wood evenly from the belly to counter it.I removed wood from the belly till the fracture was completely gone with the wet finger test on the fracture area.Yes I do wonder about the backs' integrity that's for sure.For now I don't see anything to raise a red flag.I guess it's been pulled to 28" at least 500 times or so through tillering and shooting.So I'm hoping for the best of course.No wraps on the section in question.

[BowEd]

Oh the maple core was a shade less than 7/16ths' inch thick at midlimb before I glued the horn on.

[MWirwicki]

Great save, Beadman!  8 years is of course better than 6 weeks.

[BowEd]

Yea Matt Marc St. Louis and me traded.I sent him a black locust.Mid limb on this bow is only 1 and 3/16ths' wide though hence the low mass weight on it.The fades are 1 and 1/4" or less from side tillering making the stiff portion of the handle to somewhere between 6 to 7 inches.
The compression fracture was my own doing.I did'nt notice the area a couple of inches out from the fade to be thicker than it should of been.Hence it made that limb have a longer handle than the other limb.
I've noticed in the past issues of PA that you've used horn a bow or some bows too.Tremendous bend you got from your short composite you made.Congrats.Have you done more too yourself?I'm currently investing some time and effort into a horn bow with the grooves and all.It'll be an experience I'm sure dealing with twist and tillering with heat and all.I went after the reccomendations that Jeff Schmidt showed in his video but read a bunch into the Ottoman book of Adam Karpowitz too.Not that many bowyers on this want to fool with the horn routine but for some reason it tweaks my interest.

[MWirwicki]

It tweaks many's interests.  You picked the right book.  I am getting the hankering to build a similar bow, only I have a few different ideas up my sleeve.  I'll start on her this year, though.  Looking forward to seeing what you come up with!