Sinewed bow

[DC]

I'm about to take the next step in bowyery.(sp--word?) I want to get something straight. I make the bow and tiller it out to about 20". Then I reflex it and apply the sinew. Then I put it back on the tree and finish tiller as usual? I guess what I'm unsure of is if there is any difference in tillering a sinewed bow and a self bow?

[Pat B]

The tillering is the same. It is possible that the tiller will not change if the sinew is applied evenly on each limb and both limbs but the weight will increase. Realistically expect to have to at least freshen up the tiller.
 When I build a sinew backed bow I tiller it out partually, estimate my ultimate draw weight at my draw length then add the sinew. This way you have a limited amount of weight you have to reduce and you should be able to get the tiller right while reducing the weight. Be sure the tiller is right before you add the sinew.

[bradsmith2010]

i have found that the sinew bow responds a bit different to wood removal,, so going slowly is advisable,,

[Danzn Bar]

i have found that the sinew bow responds a bit different to wood removal,, so going slowly is advisable,,

Yep happened on my last one
DBar

[PEARL DRUMS]

I would suggest getting the bow heat shaped and lined right up, then tillered out to 18-20" max, then apply sinew with a slight reverse brace.  Brad and Bill are right on. Exercise the bow more than usual between scrapings. 

[mikekeswick]

You only get those 'problems' IF the sinew isn't totally dry. 1mm sinew = 2 weeks, 2mm - 4weeks, 3mm - 9weeks, 4mm - 16weeks.

[Danzn Bar]

You only get those 'problems' IF the sinew isn't totally dry. 1mm sinew = 2 weeks, 2mm - 4weeks, 3mm - 9weeks, 4mm - 16weeks.

At what  RH?

[simson]

Good advice above!
Be sure to get the sinew on in an homogen thick layer. If not, one way is to fill up with new sinew (+ waiting and reverse brace), or tiller also on the back (before you touch the belly)

[Stick Bender]

With reflexed sinew bows it's easy to miss your target weight you really need to get the sinew working to show it's true colors I try to bring the bow to brace about 20 lb. above my target weight the last one I was working on had about 7 in. of reflex it took 100 lb of weight to get the limbs neutral and after sweating for 2 hrs at neutral  it only took 70 lb to neutral I think it depends on the amount of sinew you use also. After trying different cure times from 1 month to 10 weeks I agree with Mikes method of cure as much as I hate to weight for cure !

[DC]

The bow is a static recurve. How far into the non bending part should I take the sinew? I had to kerf the recurve and I like the look of the dark insert. Does the sinew have to wrap over the side much? I'd rather not cover the insert unless it's needed.

[PatM]

Just feather the sinew into the center of the curved portion. The sinew does not need to wrap around the sides nor should it need circular wrapping at the extremities.

[DC]

Thanks Pat. The bow has a high crown, are you of the school of thought that says concentrate the sinew on the top of the crown and just barely bring it out to the edge?

[PatM]

Yes but I still  like complete coverage even if thin at the edges.

[JW_Halverson]

If in doubt as to whether your sinew is cured, wait. 

[bradsmith2010]

i have done some pretty fast cures,, cause I have a problem with patience sometime,, the bows did gain weight, but performed well,,,, that being said, there is no doubt waiting longer could be better most the time,,