another core question

[stuckinthemud]

Hi Guys,

took the pup through the woods this morning and found an extensive copse of silver birch with many the right size for cores (saplings about 10-15cm diameter); am planning on returning there with a saw over Christmas.  Karpowicz suggests using green wood, soaked and boiled and bent to shape and left to season.  What is confusing me is whether you just strip the bark and cleave/plane to thickness and have a D-profile lath like a self bow, leaving the outer rings intact, or, if you use a section from nearer the heart of the stave and planer-thickness a rectangular-section lath, or is either approach OK? - I am planning on using hollow section horn, if that makes a difference? Thanks for your patience!
Andrew

[EdwardS]

Rectangular laths.  I have so many I don't know what to do, this is a good idea.  If you have questions about Karpowicz's intent, the pictures normally show what you need to know.

[mikekeswick]

Yes leave the outer fibers intact. Make the tip area 17mm thick, step down to 15mm at the tip bend as that helps to control it better than same thickness everywhere. 15mm is good for the rest of the lathe.
I wouldn't use silver birch though. You can experiment with lighter core woods later but for the first few bows use proven wood or else you are heading for headaches! I would strongly suggest you follow the advice in Adam's book to the letter! The birch he mentions is yellow birch - Betula alleghaniensis, silver birch is Betula pendula.
The easiest route to a good core is to make it 5 five piece. Look for pregrown recurves. Most Hawthorns have something suitable. Ash is another good candidate where branches come off the trunk. Then you only need to make one bend in the lathe, the kasan eye bend. As this is over a greater radius than the tip it isn't quite so problematic as a 3 piece core with the extreme tip bend and kasan eye bend in one lathe. You can even use kiln dried maple for this if the grain is good enough....but of course green wood is much better.

[stuckinthemud]

Thanks Edwards, the pictures in Karpowicz' book seem to show both, which is why I am so confused.  Thanks Mike, I wondered if it was yellow or silver birch, I have collected the components for a five piece and am starting prepping them, hence the question.  Sinew is arriving end of Jan, hoping to get the horn about the same time. Might start a single thread as I go along so I can keep all my numpty questions in one place 

[stuckinthemud]

Well, its done, three sets of horn winging their way to Wales Lots of numpty questions will, no doubt, be asked over the coming months, think I'll post them here, keep em all together

[stuckinthemud]

Right, the horn has arrived (ulp!) so, what do you guys think is the best way into horn bow making?  Also, I could make a 1 piece, a 3 piece or a 5 piece core  but if go with a 1 piece then that is 1 less self-bow I can make  - which way would you go?

[mikekeswick]

First process your horn and get the strips done. Then you will know what you have to work with.
The easiest cores to make are 5 piece if you are going to make a Turkish bow.
There are of course many designs to try but why not go with a Turkish bow as you already have Adam's book (?). The way to succeed is to follow every step exactly as he says, when you start thinking oh I could just do it this /that way instead...stop make a cup of tea and go back to following exactly what he says!
It took me two attempts to learn this.....that book is pure gold and has everything you need to know in it.

[stuckinthemud]

Hi Mike,
I think the main reasons for not necessarily doing a Turkish as a first horn bow is that they appear to me to be more of a technical challenge, and more time-consuming, than something like a Magyar.  Equally, my main interest is in target rather than flight archery so a bow designed for medium weight arrows over a shorter range might be more suited to my requirements, as would a medium weight bow - I can pull 50# but can't get much beyond that at the moment. I am really struggling with Adam's descriptions of the differences between target, flight and war-bows, I have read and re-read the sections in his book and cannot get my head around it, so, while a Turkish is definitely one of my targets for this batch of horn, it might be better as horn bow number two or three?  Having said all that, processing the horn then deciding makes perfect sense and, anyway, I ALWAYS over-think things!
Happy New Year,
Andrew