Old bows

[Dennis La Varenne]

That's a fair enough comment.

For future reference, if you do have an inclination to go down that road, I have some Hickory lams here, 1/8" and 3/16" thick. I am happy to send you up a pair of 36inch lams so you can scarf joint them and put them through your tapering machine at 2 thou/inch taper or whatever you have in that regard then glue it onto the back of a wood stave using your normal gluing form, especially if it has some reflex. Putting taper in a backing lam will help to keep tip mass down.

Don't cook the glue to cure it. Just let it air cure so that the plastids in the wood aren't remodelled by heat. That will put the belly in tension and the back in compression which is the Dan Perry reflexing system. It will preload your limbs a good deal without bringing the wood under excessive compression and should give you a good bit more power.

Perry reflexing is usually done cold on a tillered bow so that the reverse bending keeps the original tiller. It is usually reverse bent up to 6 inches while the backing is applied. Most of that will come out, but it will still retain a goodly amount of reflex with all of the consequent performance benefits.

A Perry reflexed bow produces a bow which is reflexed at rest. When you brace it, the wood moves from a resting state of compressed back/tensioned belly through to a neutral state as the limbs move past straigth with zero stress on the back and belly to the normal tensioned back and compressed belly. That first part of the bend from reflex to straight stores additional energy in the limbs that a normal wood bow with string follow or even straight does not have. The end result is that a Perry reflexed bow with 1 1/2" of resting reflex stores the equivalent energy of a straight bow being drawn to 29 1/2", or compared to a bow with 2" of set, it will have around the equivalent of 4 1/2" of additional limb-stored energy.

If the reflexing is done under heat so the wood plastids are remodelled, the fibres are at rest in a different shape under no tension or compression. It will still perform better than a straight bow or a bow with some set, but not as well as a Perry reflexed bow where the wood fibres do not come under back tension and belly compression until the limbs have moved past straight - if that makes sense.

[bigbob]

thanks for all that info Dennis, I am cognizant of most of the info you presented but it read so much more germaine that even I could decipher the data involved. It will be very handy when i get the time to do another all wood bow. If i had a bit of seasoned Moso laying about I would be doing something now as I am just waiting on an order from US to do an order and it is at least 2 weeks away.

[Dennis La Varenne]

Yes, we've all got plenty to do. One thing about the heat treatment though is that it works with just about any kind of bow backing without hurting the glue joint. I found that out almost by accident. Most of the bows in my collection have all sorts of backings and from Hickory, fibre, sinew and clarified calfskin which is only thin rawhide and none of them were damaged by it which is good to know.

I am glad you could follow the process OK.

[bigbob]

I thought the heat might have loosened the backing glue, but that wouldn't matter in any case 'cause it would be a simple matter to glue back after the reflexed section had cooled and 'set'