Well, I tried to use PatM's method, and I screwed it up. Basically, I put way too much sinew on and did not fray it out as finely as I should have. This, combined with trying to squeeze excess glue out, resulted in a mess of sinew that was applied way too thick and was likely going to not be very uniform in nature at all. So, I pulled it all off shortly after I wrote the last post and went to bed agrivated.
I missed a key question to myself prior to starting this: what is the purpose of this sinew job? Ideally I want protection against the bow taking set and enhancement of performance. This bow is performing well, so I should have entered the project with the idea of erring on the light side, as it won't take much of a sinew layer to provide the benefits of raising the tension plane some and protecting the belly from set.
I do have it strung backwards in the photos. I added just a tad more reflex by shortening the string a touch.
I also make the mistake of wetting the sinew bundles and letting them dry before trying to rehydrate and saturate with glue for the backing job. Don't do this!
Saturday, I woke up and started processing out new backstrap sinew, and I took extra time to get plenty of bundles of varying lengths well processed. I took them to the bow and laid them out according to how I was going to put them down on the bow with a deliberate, thin, three layers in mind with an extra crown layer running down the center of the bow. I weighed each bundle to make sure each corresponding bundle was approximately the same amount as well as to come up with a total sinew weight used to back this bow for future reference.
During processing, I noticed three particular backstrap tendons were particularly greasy/oily, so after laying the bundles out in the order I was going to apply them, I got my glue mixed (2 cups of water and 6 packets of Knox) and prepared my double boiler.
I then filled one side of my sink with a very strong dawn and warm water solution with the faucet set to the other side. I took each bundle and washed them thoroughly in the dawn and warm water while working any tangles out of the frayed ends. After washing, I rinsed them thoroughly under warm running water while ringing them out and stretching them as much as possible...this stretched the bundles and aided in making sure they were clear of the dawn and oils the dawn took with it. I laid each bundle back where it came from and smoothed it out and left them very wet, as I did not want to have to deal with the pain of a wet bundle that had dried prior to going in the glue.
As soon as all the bundles were washed and flattened, I sized the back and sides of the bow again...probably didn't need to considering the previous job, but I did for good measure...and I started dipping for 20-30 seconds, wringing out all the excess glue (different than PatM's method) and laying down the first layer per usual. I spread each layer out per usual, and proceeded to apply three layers well overlapped and brick-patterned taking care to get the overlapping ends and bundles "smushed" together and melding. I used nearly all of the bundles I had prepared, but I did have some left over. The leftover is drying now, and I'll weigh it tomorrow and subtract it from the total weight of the bundles I had prepared to know exactly how much I put on the bow. I want to get some exact numbers with this job to try and dial in some exact numbers for future projects and for others to reference. If it turns out that I needed to add more sinew, Ill know what weight of dry sinew to prepare and apply next time...same goes for if I realize that I overdid the job and hit or passed a point of diminishing returns.
After I was done, I did apply one liberal coat of warm hide glue to the entire back to get into any areas where fresh sinew was being laid upon or beside already gelled sinew and maybe did not meld together as well as I wanted. I gave that a chance to start gelling, and I tightly applied co-ban wrap which is very elastic, easy to work with, breathable, and self adhereing. Once wrapped, I used a thin vase and rolled up and down the back with enough pressure to smoothe it out, but not so much to move stuff around. As I did this, I tried to keep in mind the crowned contour of the back. I did use PatM's method a bit at this point, as I took out the hairdryer and heated everything up until the coban started to absorb the excess glue I had slopped on at the end of the backing process.
Not wanting to pull any of the bundles or fibres up, I put the bow in my small bathroom with a window unit, and closed it in there. After an hour, I slowly started unwrapping the co-ban, because I was worried that I may have glued it to the back of the bow. As I unwrapped past the thinner layer toward the tip, it came free very nicely from the smooth sinew that had already dried fairly well. The next wrap revealed that the thicker areas were still wet, of course, as I progressed into the meat of the limbs, so I just wrapped it back up and stuck it back in the cool, dry bathroom. I'm going to leave it as is for 12 hours and remove the wrap early tomorrow morning and give her a look-see.
I am much, much happier with the amount I laid down this time, and I'm hoping my wrapping job did not displace any sinew and leave any exposed edge spots or wonky, off center high areas. Regardless, I'm optimistic. I did video this whole shebang from processing the sinew to washing it to laying it down to wrapping her up. I did this because all the videos and advice I seem to find on youtube and in TBB and on forums seem to live in the realm of the subjective. While I know this is an art and there is no set formula, knowing things like..."2 cups of water and 6 packets of knox gelatin produces resutlts that work perfectly for me" would be much better than "I put about yay amount of water and two or four packets of knox and stir it up till its about light brownish and the consistency of table syrup or a little thinner." It may not really matter, as some have hypothesized, but when you are new at something and doing it for the first time and not wanting to screw it up, it is helpful to have as much concrete, non-subjective info as possible...at least it seems to be helpful in that you can proceed with less doubt screwing with your mind as you go.
I'll take some pics of the unwrapping tomorrow, and once this is all done and I'm flinging flaming arrows with it, I'll try to edit the video into something watchable and get it posted up too.
Thanks for all the advice; hopefully I will find out that I put it to good use.
