Well.... (Questions Added - Page 2...)

[arachnid]

Hi guys...

So I started a tri-lam reflexed longbow this week, floor tillering and long string tillering
went well. Then I wanted to string it on low brace and ... KABOOM!!!!..... that thing exploded on the tiller.
I `m not sure what went wrong, did I try to brace it too early or was it a grain run-off on the back (I thought white oak is tough enough to handle one run-off...).

Can you tell from the picture? (BTW, the bow it white oak backed ipe with walnut core)






I think I`ll stick with straight pyramids for now.... too many reflexed bows broke on the tiller lately and I don`t think the
faw extra FPS is worth the it.....

[chamookman]

You answered Your own question on the grain runoff. Bob

[Pappy]

No expert on board /lam bows but looks like more than a little run off to me. Sorry
  Pappy

[arachnid]

Well I guess I'll have to pay more attention when choosing a board next time...

[Aaron H]

It's not the reflex that got you, it was the grain run off.

[DarkSoul]

Too much grain run off. The grain runs at an angle, from upper left to lower right corner. More than one ring is running off.
To add to that, the back is also not smooth. I can see circular saw marks still present on the back. That's not good. Although you did round the corners nicely, the back needs to be smooth as well. Those saw marks basically create tiny ridges for a splinter to lift.

[H Rhodes]

It looks like it started at a knot that was a little too close to the edge.  That combined with the grain runoff was too much.  That can't be "it" for you!!  If you aren't breaking one now and then you just aren't a bowyer.  Get back on that horse!

[Drewster]

Yeah, just think how much you've learned from this bow and apply that new knowledge to your future bows......definitely don't quit now.  You're a better bowyer for the failure.  I always learn more from the bows that fail.

[arachnid]

Never said I'm going to quit!
I'm too hooked with bowmaking...what I meant is I'm sticking with stright flatbows for now (I have more luck and experience with them). It's pretty annoying to have a bow explode because of a grain runoff. Thats like the ABC of bow making and I'm scratching my head trying to figure out how I missed it.
BUT, since you guys encouraged me like you did, I'll just concentrat my searches in finding better boards. That board was given to me for free, so I guess it's sometimes better to pay for good stuff the get #$@%¤ stuff with no charge...

One thing is certain- The lesson is learned.

[Parnell]

Never said I'm going to quit!
I'm too hooked with bowmaking...what I meant is I'm sticking with stright flatbows for now (I have more luck and experience with them). It's pretty annoying to have a bow explode because of a grain runoff. That like the ABC of bow making and I'm scratching my head trying to figure out how I missed it.
BUT, since you guys encouraged me like you did, I'll just concentrat my searches in finding better boards. That board was given to me for free, so I guess it's sometimes better to pay for good stuff the get #$@%¤ stuff with no charge...

One thing is certain- The lesson is learned.

Amen.  Gotta ask yourself what your time involved will be worth. 

[mikekeswick]

Pyramid, longbow, recurve , reflexed, deflexed everything needs straight grain on a backing strip.
I too have learnt the hard way 
One tip when looking for a good enough board. Concentrate on flat sawn boards - they are way easier to 'read'.
If it is thick enough you get to cut the backings quarter sawn. If not - it doesn't matter anyway!

[arachnid]

Pyramid, longbow, recurve , reflexed, deflexed everything needs straight grain on a backing strip.
I too have learnt the hard way 
One tip when looking for a good enough board. Concentrate on flat sawn boards - they are way easier to 'read'.
If it is thick enough you get to cut the backings quarter sawn. If not - it doesn't matter anyway!

Nice tip. Thanks.
If the grain is straight on the outrr edge, is it certain that it'll be straight "inside" the board (when ripped)?

[mikekeswick]

Choosing boards is really about eyeballing them from all four sides. On a flat sawn board the 'flat' faces may look bad at first glance BUT the sides are then very easy to read. If the sides are straight lines you've got a good one. The flat sawn face unless from a PERFECT straight tree cut parallel to the surface will have a few islands etc.
It's hard to describe this sort of thing in words.....a picture speaks a thousand words and all that!
Maybe somebody else can describe what i'm trying to say better 

[arachnid]

I got it.
What I was wondering is- when I start ripping the board from the side, is it certain that as I go "deeper" ,to the width of the flat side, the grain will remain straight on the quarter sawn side?

[mikekeswick]

Look at all four sides and if there is runoff somewhere you will start to see v's on an edge. If all four sides show parallel lines the full length of the board with no v's on the edges then yes the grain will remain straight.