Spin-off from the sinew backing question thread and two build alongs

[ssrhythm]

Left it wrapped overnight for ~ 12 hours.  Removing the co-ban wrap, the glue excess glue expressed and absorbed by the wrap when I put the hairdryer to it did actually glue to the back.  I used a lightly dampened sponge with warm water to lightly wet the wrap as I removed it, and it slipped right off.

The job looks amazing and smooth, and there will be no sanding required prior to applying tight bond 3 to help waterproof and hold down the snake skins used for camouflage and waterproofing. 

I re-wrapped with gauze to keep any critters from gnawing on it, and I’m hoping that this thickness will be perfect and will sufficiently dry/cure within 15-20 days.  I’ll check it with moisture meter in 14 days and proceed from there.

Total dry weight of backstrap sinew used was just a smidge over 3 ounces applied with a 1cup of water/3 packets of Knox gelatin glue.

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More pics:

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Last pics at this phase:

[bownarra]

There is no way 3 ozs/90 grammes will be dry in less than 3 weeks. Refer to what I said above about thickness/drying times..
It may look and feel dry on the surface but It is the sinew directly on the wood that takes the longest. The wood will also soak up the moisture in the glue. Pulling a sinew backed bow too early will result in you simply not getting the performance that you could've. If the bow is finish tillered without a fully cured backing you will have a bow that will gain weight over time.
If you apply sinew in thin layers you can dry it quickly. The Koreans used this method on their hornbows.

[ssrhythm]

I'm just hoping for the most optimistic outcome regarding curing time.  I've put way, way too much time and effort into this backing job, let alone the overall build, to screw this up with impatience.  This is a ridiculously dry climate, and I plan on getting this outdoors in the low humidity, low 90 temps, and constant wind after letting it dry under compression wrap for two weeks.  I will absolutely be using the moisture meter on the handle section where the thickness of the sinew is the greatest, and I won't start in on trying to bend it again until the reading there indicates it is sufficiently dry.  What should I be looking at on the moisture meter to ensure that it has dried and cured enough to start bending again?  Thanks again for the tips, advice, and guidance.

[ssrhythm]

Ok Bownarra...I've had it outside for the last three days from 1pm till 5pm when the relative hunidity dipped below 20%.  Average relative humidity during its outdoor time has been ~18%.  Reflex increased 3mm the first day out, 2mm yesterday, and < 1mm today.  I stuck two moisture meters into the sinew at the thickest area on the back of the handle and tried to bury the probes to the wood.  One meter has 8 wood modes, and it read 7.2%  to 10% as I flipped through the wood modes.  The other meter just measures "wood" or "bldg" and it measured 7.3%.  Clay Hayes suggested anything under 10% at the handle would be good to bend.  The bow has been wrapped tight with Coban this entire time, and the sinew is smooth and flat. 

So, tomorrow will be day 7 and its already below 10% at its thickest spot.  My 1.5 year old staves that are hanging in the garage will not read on the moisture meter even when I cut off an end and bury the probes as far as I can into the end grain, so they are at 5% or less.  Y'all think I should leave it unwrapped and let the next couple of afternoons with RH vlaues dipping to ~16% work on it a bit more, or should I take it out and put on the tightbond 3 when the RH  is at its lowest and just get on with it?

Thanks.

[ssrhythm]

Left the bow outside in 14% RH and 90 degree windy weather yesterday unwrapped.  The moisture meter reads 3.7% on building material mode at thickest sinew on handle, and it reads from NR to 8.1% in wood mode depending on the wood type chosen.  Bottom line is that in 8 days, the 3 oz (dry weight) of sinew is plenty dry, smooth, and looking good.  We are just now hitting the time when RH values outside are again droping below 18%, so I'm about to take it to the garage and sand the overlapping sinew off the sides and arrow shelf and neaten up any straggling pieces etc.  Going to apply a thin layer of TB3 to add moisture protection and to size the sinew for upcoming skin application.  Then, I'm going to start bending her.   I'm actually worried about the extremely low moisture content in the wood at this point.  If I can get the poundage down to where I want it and keep/improve the tiller without it exploding, this should be a very snappy and sweet hunting stick.  Posting this now, because I am actually pretty "terrified" about moving forward and experiencing a catastrauphic failure.  Regardless....here we go.

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Ok.  I’ve scraped it down to where the bend looks good to my eyes, the bow pulls 60# at 27”, and its Holding a hair more than 1/8” positive tiller at. 6 3/4” brace height.  I flung 30 or so shots at 15 yards with a variety of arrows with spines ranging from 51-55 to 70-73 in river cane as well as a few 65-70 sure wood Douglas fir arrows.  The best flying arrows are the 62 to 73 lb spined river cane, but they all flew fairly well and hit Where I was looking.  I finished up with 6 shots with the best 4 flying cane arrows, and the 15 yard group was tight enough for me to pull them all with one hand.  I figure I’ll lose a pound or two during sanding and finishing, so I’m calling it good at this point…it’s s bit heavier than I’m used to, but it was not uncomfortable to shoot, so I’ll work diligently to increase my strength and comfort level with this draw weight.

Below is the bow on the rack drawn to 60# at just shy of 27”.  Tape on the back (keeping my oil off the sized sinew) makes it look a little wonky, but this is as good as I can do at my current level of experience. 

The next pics will be when I have it finished.  I have the entire process on video, and when I figure out how to edit to make it watchable, I’ll post the link here.

Thanks for y’all’s help along the way.

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Ok, I'm putting this thread to bed...you are welcome .  I originally wanted to and thought I would progress throught this build much more quickly than I have, and I thought I'd likely be nearing completion of the second bow made from a stave with smaller growth rings and more prominent early wood in order to compare the whole "does a thick ring stave or thin ring stave make a better bow all other variables being equal."  Well, there's no way on earth, at least for me at this point, to come close to having all the other variables consistent enough to gain any relevent insight on that subject...so I'm not even going to try.  The next bow will become whatever it becomes based on what I think needs to happen as I progress through the build. 

That said, I am done with this bow build, and I am absolutely thrilled with how it turned out and with all the things I learned in the process.  I truly appreciate all of the advice and encouragement given along the way.  I realize that I might be asking questions with obvious answers or that may not even make sense at times to the experienced builders on here, and I lack the gift of brevity, so thanks again for any help given along the way.

I am going to post some pics and specs from the bow after 10-12 ish layers of truoil was applied in a new thread titled "Lil Eddy," but I will also post the true finished pics sometime this weekend, as I decided to apply a few layers of thinned Varathane Spar Urethane wiped on over the TruOil, and it is currently in the final 48 hours of the drying process now.

Thanks again.