So I just checked my scale on a gallon of water. Store bought, may not be exactly a gallon and the thin plastic bottle doesn't add much compared to the water- so it should be close but probably not exact. The interwebs said it should weigh ~8.34 lbs and my scale called it 8.61 lbs- not perfect but not very far off and probably within the slop from the store fill and container.Huh, maybe I should check my scale. It's been through a few drops and a couple of bow building blowups, but I've never had reason to question it, or check / calibrate it.I'll complicate issues more. I picked up a new luggage scale today and took some readings on my bands at 31".
.5 BSB white 27-18 , 6' active length------12.25#
.5 SSblack 27-18 , 6" active length-------13.75#
So aside from a small sigh of relief over the bow I am currently working on, but I'm puzzled over our different numbers. And actually, the sigh over the current bow project is significant- after a few spectacular blowups with a hickory backed maple laminate I learned a few things and have one I am optimistic coming along. Hoping that what I am trying to make around 45 lbs won't come in at 31!
I wonder what could be causing the difference. The Simpleshot 0.5 I tested is nearly a year old, always stored in the dark but mostly at room temp (a couple months in a fridge at my office but half or more of the time at ambient temp in my garage, but always in the dark). And while it isn't a great check, my feeling from drawing all 4 brands of latex is that the scale got the relative weights right even if the absolute numbers are off.
But I think this is the strength of a forum like this- I appreciate hearing about the difference in our measurements and hope that figuring out the explanation for it will be enlightening.
I will recheck my numbers on the bands I tested later today or tomorrow to make sure I didn't have a silly mistake in how I measured.