Can you back on top of sinew

[DV of WI]

I made a osage s-bow and backed with sinew. Came out 40ish @ 28. I would like to add some weight, can I put a strip of bamboo or hickory on the back over the sinew?

[rainman]

Add more sinew, I don't think you can back over sinew.  How long has sinew been drying and how many layers of Sinew?  You could add a horn belly also.

[John Scifres]

I agree.  It seems to me that adding another layer of something to take over the tension work on the back would move the relatively heavy sinew into the neutral plane that does no work in the bow.  You might be able to get it to hold and you might be able to get the weight up but I'd bet you won't do much for the efficiency of the bow.  

That being said, I've never tried it so give it a shot and see what happens. Experimenting is fun.  Post pics and results.

[DV of WI]

The bow was dry heated for set the 3 layers of sinew added w/HG which pulled off as one piece after drying then after cleaning with acetone was reapplied with TBIII and held well. All this was done in early July. Bow has very good snap to 20-25 yards with 530ish grain arrow but loses cast after that. The bow is fine and does what it should but I geuss I would like to wear out my shoulders and elbows. Its just not the weight I was gearing for. I know just make a new bow.

[Mark Smeltzer]

The bow may gain weight over time if left in a dry place and if it does, seal it very well.  I have had sinew bows gain 5-10 lbs in low humidity conditions. Make sure it is completely dry! This could take months depending on the drying conditions. If not maybe piking the limb tips is an option, sinew lends itself to a shorter bow very well. To me a decent sinew bow should be less than 60" unless other variables come into play like a long draw or a non working handle and or tips.
Mark

Mark

[rainman]

You could also laminate a wood strips on to the belly, easier to do than horn.

[Pat B]

I added a belly slat(Argentine osage) to a cherry bark backed osage statiuc recurve that had fretted and was under weight. It was 47#@26" and after the belly slat I retillered it to 55#@26" and it shoots like a champ. It is my hunting bow for this year.