There's a hole in my belly!

[Philipp A]

HHB is all I use for my bows. I have not had functional issues with some cambium left on, but found it to be more difficult to get a good bow if it is a heavily crowned stave (could be my level of skill of course). I have now gone to larger trees where I only have a lightly crowned back. The bow stave in the picture does not appear to be heavily crowned, so I am thinking that you should still get a functional bow out of it despite the hole.
 
Any holes or larger knots I had, I have drilled and then scraped them out and filled them with wood filler or mixed my own sawdust and white glue and not had any issues. I was mostly lucky by having mine closer to the handle where I had more wood to work with and they didn't go through all the way.

Question for PatM: What has your experience been with HHB? Are you always taking all the cambium off? I find that the only time I can get it easily off is with a tree taken in the spring or early summer. Also you have frequently small ridges just below the cambium, do you touch them or do you also leave them intact. I personally don't touch them at all, I find it adds character and beauty to the bow and I have so far not getting tension failures as long as the bow was not too heavily crowned.

[PatM]

I make it look like it was peeled when the sap was running. Everything is left intact.

[mikekeswick]

You don't appear to have left extra width around where that knot is.  Not 'adding' the extra width a knot is taking up will lead to chrysalis. I know it can be hard sometimes as that knot doesn't show too obviously on the back but you need to rtealize that say that knot is 1/4 wide then you essentially have 1/4' narrow spot on your belly to take the compression. Plus the concensus on knots appears to be to leave them stiff (I don't wider is better than a thick spot on a limb) - again throwing more stress onto that spot. HHB is awesome in compression so hopefully it will be ok for you...

[PEARL DRUMS]

When I run into knots in HHB that don't go through, like so often they dont. I just leave them be and soak them with super glue until they wont accept anymore. Your back looks fine to me.

[Marc St Louis]

I do as Chris but I also leave the area a little stiff. 

As Pat says, the back will probably be okay as long as the bow is kept low stress.  You can help it out by using a shallow D section belly

I have left cambium on HHB many times.  If there's too much then it will pop a little as you tiller, very unnerving.  Once the bow is tillered out you can use some steel wool and lightly rub the back, it will snag any loose cambium and remove it.

[upstatenybowyer]

Great. Thanks everyone.

[bradsmith2010]

it would be very easy to rawhide back it,, if you are worried,,,
also keep in mind,, everyone keeps mentioning a low stress design,,  because of the hole, probably a good idea, maybe little less on the draw weight or draw length,,

[upstatenybowyer]

^ gotcha. It's an ALB, 68" ntn, which shouldn't put too much stress in any one particular place. I've got it tillered out a tad bit light for me, 45# @ 27" but I was going to toast the belly and that will probably add some weight.

[PatM]

  Toasting the belly will make the back situation more potentially iffy,

[upstatenybowyer]

I thought of that. Man, I'm really torn should I go for the beauty of a natural back, accept the lighter weight and a little more set, or do I heat treat some reflex in and rawhide back it? Pat, I'm wondering what you would do...

[Danzn Bar]

You know ....It's what "you" want to end up with.....
DBar

[PatM]

Even if it's a bang on the head. 

[bradsmith2010]

your at the "bowyers cross road",,,,,only you can decide,,
go for the more sure thing,, or risk it,,, to gain a bit of performance,, sometimes Better is the enemy of success,, but no guts no glory,, see you even have me confused,,,,,,

[upstatenybowyer]

^ AHHHHHHH!!!!!!

[osage outlaw]

I would finish that bow up and not think twice about the back.  That's just me though.  I scraped off the cambium layer on the white wood bows that I have made and never had a problem.  Do whatever you think is best.  It's your bow.