New bow from a newbie

[iangriffin]

Hi
I'm Ian from from bolton UK. I make laminated bows. I don't use any glass or carbon fibre. I only use ash, maple and white oak at present. My bows  are 64ins long, pyramid limbs. The limbs are made from 5 lams normally in the order of ash - maple - oak - maple - oak. The limbs are set into the handle with the top limb set at 4ins forward (reflex but not curved) and the bottom limb at 3ins. This makes the bow asymmetric, making its very smooth and fast. After tillering the limb tips have a slight (1 inch deflex ). I made this bow for myself. I like bows with 80- 100lbs draw weight at 28in draw length. I draw the bow with a ''getting into the bow method'' , commonly used by warbow users. The lams I cut from 60in x 4 x 2 ins and then sand them to size with a broad drum sander. Thereafter, everything is hand tools only. Its not pretty or graceful. It reminds me of a mini hand held balister. But it's very accurate and lets me use any weight of arrow between 400 - 900 grains. I prefer tonkin bamboo shafts. Being hollow they allow me vary the point weight as needed. Please comment (I have thick skin) . I'm having trouble posting pics. Will post them when I sort it out.   

[ajooter]

What is the draw weight on that particular bow?  I like the way you have reflexed the limbs in the handle.  That seems like a lot of weight for that configuration.

[Pat B]

The handle/limb configuration scares me, especially for a 80#-100# bow. At that weight a delamination could be very dangerous.
 Can we see you at full draw to see how it bends and an unbraced pic.

[WillS]

Are you familiar with Ian Sturgess? He's from Bolton also, and you won't find many who can make heavy laminated bows (and shoot them) as well as he can.  He's got an account on here under "Ian." (including the full stop) and should be able to help with various things. 

Your bow looks very unique - would have to see it at full draw to really get a good idea though.

[iangriffin]

Thanks for the questions, here are the answers:
Wills - I don't know Ian Sturgess, but I will certainly try and contact him asap. More pics will follow soon.
Pat -  B I have practised drawing and shooting this 50-60 times without incident, so far so good. I have also used the same limbs in a short flatbow without a problem. But, a long term test (6 months of regular shooting, approx 1300 arrows has not been done yet.)
ajooter - this bow draws at 80lbs at 28ins. Allow a bit of temperature. I should also mention that during tillering, my long string broke at 135lbs at 16ins. With no damage to the bow. But I had to change my underwear. Please, can someone tell me if there is an better way to answer questions.

[blackhawk]

Welcome to pa..

Not sure what to think of that handle configuration    Kinda scares me too to be honest...what kinda glue did ya use?

[sieddy]

Alright Ian great to see you on here and I look forward to seeing more of your bows. 80-100!?!  that's a right little rocket launcher! Big up Bolton!   

[medicinewheel]

Sorry, but I think this is too serious to not point it out clearly: If you intend shooting this bow, you will be endangered and so will be those standing around you!

As Pat says: this is a scary configuration. 
Even if the glue lines were perfect - which they are not - they would not have enough surface to hold together in the fadeouts and the handle layout will reduce that surface evenmore. Even for a light weight bow I would not consider this save. The square extra piece in the handle I hold for the most fragile part of the construction. Remember the limbs will work as levers on these glue surfaces - evenmore with the set back and the glue pockets in the voids will not hold up!

Why not laminates of one piece running trough the handle? With set back glued in? Even then the glued on handle block must have an invisible glue line! To achieve that I  would laminate thin strips to build up the riser.

I marked the spots that I consider dangerous:

[iangriffin]

Hi medicinewheel

Thanks for your input. Initially, I felt the same way as you. But I'm using newbie logic, which may be wrong. Thats why I'm here. This is the first of its kind, mistakes have been made. First mistake, rounding the limb edges before assembly. This produced some of the poor joints you rightly mentioned. The solution is assemble first. The other poor joints are newbie mistakes and will be fixed with more practise. Time will tell whether the other dangers you mentioned are justified. I use tb3 glue. I've seen it demonstrated on youtube, the wood on a joint breaks before the glue does. So broadly speaking, the glue welds the wood together. So in effect the handle becomes a solid piece. In my earlier reply post, I spoke about an incident when my tillering string broke. It seems to support my logic. Again my newbie logic may be wrong. As regards endangering other people. If the bow breaks, it will make a big bang, maybe snap in two. But I don't agree that it will shower everyone around me with shrapnel. But if my wood welding logic is wrong, who knows what will happen? But please, I value all input, it can only help me.

[WillS]

The glue may be stronger than the wood around it (most wood glues are) but it's the amount of bending that will make it break eventually.  If you put 135# onto the bow with a long string (and you said the string broke at 16") that's nowhere near the amount of bend that will happen at full draw.  It's not about the weight the glue join can withstand, it's the force against the two pieces sandwiching your limbs at full draw.  Every inch you increase the draw length by, the limbs will be trying harder to break free from those two back and belly pieces. 

It might be able to take 300lbs at 16", but that doesn't mean it will be able to take 50lbs at 30".  Exaggerated example, but hopefully you'll see my point.  You could take a really knotty, gnarly piece of English yew for instance and put it on a tiller without roughing it out much.  It would easily take 150lbs say if you pulled on it, but once it's down to 30" and bending really hard it's likely to explode at a knot because you're asking the wood to do too much.

[medicinewheel]

... I use tb3 glue. I've seen it demonstrated on youtube, the wood on a joint breaks before the glue does. So broadly speaking, the glue welds the wood together. So in effect the handle becomes a solid piece.

... As regards endangering other people. If the bow breaks, it will make a big bang, maybe snap in two. But I don't agree that it will shower everyone around me with shrapnel.
...

Not the glue itself but the (properly made) glue joint is stronger than the wood. Bows fail at glue pockets and for glueing surfaces being to small. No matter what glue is used.

We talk about a bow of a draw weight of 80 to 100", right!? It might not shower people with shrapnel but I believe if it comes apart it will do with zero warning, most likely the limbs will rip out from the handle block and snap back at you, or the guy next to you. Eventually.

[medicinewheel]

PS: Welcome to PA!

[PatM]

I don't think it's possible to design a bow better that will come apart at full draw unexpectedly. If you want to lift a large flat rock you stick a pry bar under it and bear down. That's essentially what you have going on here.

[iangriffin]

Hi medicinewheel
I explained  about my poor joints and thoroughly agree. As per my last post. Please define eventually. One of my bows is a grozer 50lbs bio-composite assyrian style. Its my second one of these. The first one blew the core near the fades after 10 months. So do you think it would help if I put in a couple oak pegs through the handle joints?

Hi PatM I don't quite understand your pry bar analogy. I would say its more like a fishing rod. Though not as bendy. The joints on heavy duty fishing rods are not even glued. Perhaps, I am barking up the wrong tree with this bow design. Please, don't think I'm smart ass newbie. I just need things to explained in words I can understand and see the logic. If someone would honestly tell me they've built something similar and it ended badly. I would drop the design in a trice.

[PatM]

 A fishing rod has what is called "hoop strength". You just have intersecting planes.