Question on limb thickness...

[Setarip]

Hello Everyone,

I am in the middle of my second bow. (This was my first bow: http://www.primitivearcher.com/smf/index.php/topic,54681.0.html )
This new bow is from a Lowes maple board. The board itself is quite good and I measured the density at about .69 g/cm^3. Anyways, the type of bow I am working on is kind of a mix between a turkish style with spliced on siyahs, and a flat bow. I think.  The rough dimensions are 59" TTT, 7" non-bending riser, 1 15/16" wide limbs that are parallel up until about the last 4.5 inches for the siyah splices. The limbs began as 17/32" thick. The working limbs are approximately 15.5" long and are an even 1 15/16" wide the entire length.

 Yesterday I began tillering and noticed that this thing is HEAVY. I mean on the long string pulling it two inches would be over 40 pounds. I spent some time reducing thickness and bending the limbs evenly. Finally I gave up and went ahead and removed 1/16" of limb thickness.  Right now the limbs are 15/32" thick and still, they are quite heavy. I cant even get the bow into a low 1-2" brace at this point. I was not sure how thick to begin at, and on my first bow I came up way under the weight that I wanted so I made these pretty thick.

My hope is to finish this bow out at about 45-55 lbs and maybe reach a 27-28" draw (My actual draw is about 31-32" so it will be a short bow for me anyways). Do you guys have any rough estimates as to what the final limb thickness should be to get me near that weight?

[Setarip]

The WIP:

Please note: the splices came out pretty tight, it's hard to tell because of the epoxy I used(which is Smooth-on Mt-13)

[Knotty]

Is it backed with something?
If not, with such thickness it'll end up exploding on you , I think you'll end up with about 1/3 of your current thickness , my advice is to keep removing wood from one limb until you get it nicely bending at floor tiller and then replicate on the other, or just keep removing from both until you get a nice even bend at the poundage you'd like.

[Setarip]

It's not backed at all. Wow! 1/3? So you think a limb with a thickness of 3/16" would get me that weight? Seems awfully thin, but I don't know! 

[Del the cat]

If you want a 50# bow pull it to 50#
Don't mess about saying it pulls 2" at 40#.... you can't say that's heavy if you are aiming for 50!!! PULL IT TO 50#
50# on a long string is MUCH less stress than it will be when braced so you won't hurt it (unless the tiller is miles off).
Always pull to full weight unless you see the tiller is off.
If you don't do this you will end up under weight.
You don't  make a bow by numbers, you see how it bends.
Looking at the picture the limb seems to taper, and then go thick again (or even tapered the wrong way thinner near the grip!).
You need a consistent even thickness taper along the working limb. That's more important than actual thickness.... you look like you are heading towards all the bend being mid limb.
It looks like you are trying to make a pretty finished bow before you actually bend it!
Sorry if this sounds harsh, but I'm trying to save you from yourself.
Del

[Badger]

   Don't let the long string throw you off. If the long string is hanging down 16" and you pull 40# moving the limb about 2" then you are pulling about 40# at 16". Shorten up your string and do as Del suggested, pull the bow to 50#. At your length I suspect you will end up around 3/8" thick possibly 7/16 but no need to even measure thickness, you just tiller till it bends.

[DC]

You've done a great job so far, great splices. You seem to be falling into the impatience trap. A while ago I decided that the maximum I will take off between trips to the tree is 10-15 scrapes on either limb. This makes me look at it regularly. If I find myself wanting to push that I go have a coffee or something. Deciding that a whole bunch of limb should be removed at one go is asking for trouble. I've even come close to taking too much off just because I sharpened my scraper. You've heard it before,"Slow and easy!"

[Setarip]

Thanks for the replies guys.

@Del, no worries! I have thick skin. The taper looks reversed because I have the limb where the splice is intentionally thicker so it doesn't bend when drawn. I'll admit that the difference initially was not supposed to be so much, but I removed working limb material and have left the splices alone for now. It seems that I can remove a lot more from the splice joint and still keep it stiffer than the rest. I wouldn't say she's pretty yet, just have gone through and removed a lot of dead weight as I work along. Due to my lack of experience I assumed 40# after barely bending the limbs seemed like a lot of weight and would indicate a bow that was over 100# fully drawn. Lol. Thanks to you and Badger I know better now!

@Badger, thanks for the advice! I figured I'd ask for some opinions before I go and make a kids bow. :p

[Setarip]

DC, that's great advice. I definitely felt more rushed this morning since I won't get back to it until next week. Thankfully it seems I didn't go too crazy and removed too much material and still have some bow left! Hopefully I can make the desired weight.

[Knotty]

I just gotta wish you good luck with that man, and keep us posted and updated on your work, would really love to see the final result.