Autopsy (**Updated - pics added to first post)

[Innocente]

help!
newbie bowyer here, just completed longbow #8 and i've broken 5 in a row now.  3 were red oak (and all had red oak glue on handles), 1 was birch, (pyramidal design), 1 was maple (also a pyramid), all were board bows, and all were backed. i am cautious selecting boards with good grain and no runoffs, i'm careful tillering. i ALWAYS back my bow.  first 2 backed with fiberglass tape, last 3 were backed with linen cloth. i always make them long, 68" is the shortest, usually 72" or so.
the most recent explosion was a red oak board with an excellent tight backing of linen using TB II, zero air bubbles. 50# at 29#, 68" NTN, it failed on the range as i pulled the very first arrow back. (it failed SPECTACULARLY) with a loud BOOM followed by shards clattering on the ground.

what am i doing wrong? why do i keep detonating the wood?

any suggestions?

**updated, pics added of the break on this most recent one, also a pre-polyurethaning post tiller practice draw in the yard.

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[nugget]

It is hard to say without seeing pictures. Try posting pictures as you are tillering. Then we might be able to see what is going wrong.

[recurve shooter]

yeah, there are some really good bowyers on here, and usually if you get pics up, they can diagnose you.

[radius]

red oak is NOT premier bow wood.  I mean, it can make a bow.  But there's plenty of more forgiving wood out there.

It is not necessary to always put on backing.  Tillering technique, suiting the style of bow to the material at hand, and due patience all go a long way to helping you make a bow that does not break.

[adb]

Pics of you work would be very handy.

[sailordad]

red oak is NOT premier bow wood.  I mean, it can make a bow.  But there's plenty of more forgiving wood out there.

It is not necessary to always put on backing.  Tillering technique, suiting the style of bow to the material at hand, and due patience all go a long way to helping you make a bow that does not break.

not true not true

native people have used it for a long long time
not everyone has access to yew,osage,ipe etc.
native folks have used what was best in their regions for more than one millenia
just because youe have "too much yew" there is no reason to tell someone what they are using is not a good wood for making bows
hell i have read where some master bowyers think yew is inferior because of how soft a wood it is
i dont have acces to yew or osage and have made bows from hickory(alot of the time),red oak (cause its easy to find 1/4 sawn lumber),white oak,ash,hell i even have a sumac stave i
have been saving,hop horn beam.all white woods,which some say are all "inferior woods".
but they work fine for bows,ya just gotta make the bow fit the wood that you are using,you cant take hickory and make the same bow out of it that you would with osage or yew for instance

so its not realy an inferior wood

[nugget]

Well said sailordad

[sulphur]

Innocente without pics its going to be hard to help.  I was a red oak basher too, but i was using the wrong design.  Once i started making them 2" wide i was really impressed.  I would say red oak is very comparable to ash maybe even maple.  Its all about the design guys, not all in the wood!!

[Pat B]

Sulphur is correct. You can make a successful bow from almost any wood if you design the bow appropriately for the wood used.
  Pics will really help us help you. 

[sulphur]

innocente, make sure you have a design that is compatable with what wood you are using.  Jawge or PatB can tell you for almost any wood what design would be best.  After i saw Jawge say red oak is fine bow wood over and over i decided to give it another try.  he was right.  after the last bow i made from it i was so impressed i went to 3 different lowe's and a home depot to find some more good boards.  If your having trouble with tillering remember wider and longer designs are more forgiving.  I think you've got them long enough, but how wide are you making them???  the main thing is don't give up.  check out my build along on youtube for red oak.  it might help.
http://www.youtube.com/watch?v=37EPS0Xs_Tw

[Rich Saffold]

Innocente,Where do you live? Maybe the woods too dry.. I mention this because there are many variables and often it comes down to staying within the limits of the wood, both in design and what the particular bow can handle.

 Also you must realize between all the experienced bowyers here is a bazilllion exploded bows...Many went through what you are right now so what matters most is don't let it bother you, and persistence and not getting too bummed about the failures are two traits most bowyers have in common..

It's a fine line between a sweet shooter and firewood..Sulpher's advice is highly recommended by me..Longer bows are a good idea for beginners...

Rich

[George Tsoukalas]

There are 3 important things to consider when making a board bow. 1- grain, 2-grain and 3- grain. More on my site. Jawge
http://georgeandjoni.home.comcast.net/~georgeandjoni/

[tombo]

Inno- I tried 1 board bow and it SUCKED !  Maybe my singular experience but until I started educating myself on WOOD, especially wood in my area did I start having success. In my neck o the woods it's Hackberry, Elm (Cedar), Huisache and Southern Live Oak (if you can find a straight piece). Then it's grain, knots and patience. Tom

[Innocente]

design:  i'm making standard red oak bow boards, mostly - 1"x2", (so 1 3/4" wide).  i can get ahold of wider, and do a 2, even a 3 inch wide if necessary.

Note on my pics:  this break looks like it started (or ended) in my arrow cut out - but my arrow cut out was firmly and safely buried in my riser, and there was no separation of bow wood from riser wood.  this is the first break of this kind i've experienced (DRAMATIC! KA BOOM!)  except for a few forays into experimental land i've been sticking with a basic sam harper-ish design.  this last bow i tried to deviate not a bit, in hopes of making one non broken shooter. 

the one potential error i did think of on this one was:  made it 68", instead of longer, planned on too long of a draw for that length (29").  i DID carefully exercise between each tillering.

the full draw pic shows (i hope) what i fantasize is a positive tiller for my split finger. (the more i look at it it is WAY too stiff on the lower limb)

in Northern California by the way. 

[Gordon]

68"should be plenty for a 29" draw and the tiller looks really good. The picture does make it look like the failure is related to the cut-in shelf. Bad things will happen if the fade/handle design is faulty - I've learned that lesson the hard way. I recommend you avoid cut-in shelfs until you have more experience.