I noticed recently that when trying to get snags free, knowing I would probably be breaking line (using my hands to pull, not the rod/reel), that the fluoro side of my double uni leader knot was breaking. In the past, it was the lure/snap that would break off. Not often, considering I rarely snag so bad that I have to break the line, but recently I've been bank fishing and casting in/around trees where my lure gets wrapped around a branch and there's no way I can do anything but break/cut it.
Now, I didn't test the breaking strength when I got the line. I'm using Sunline Sniper FC, 3 months old, 10lb and 14lb, as a leader, paired with 15lb PowerPro and 40lb Super8SlickV2, respectively. I had no issues with breakage before. But now that I've had multiple breakoffs at my leader knot, I'm becoming concerned.
So, today I tested something. I have some 10lb weights that have a hole in the middle, so I have some paracord tied through there with a loop that I can hook onto. I tied a big VMC snap onto one end of the line and put a glove on my hand, wrapped line around it, and gently pulled up. With all knots, I used a Palomar knot, wetted decently with saliva before pulling the snap through the loop, and wetted decently again before pulling tight. Here are the results:
14lb Sniper + 20lb weight: broke before getting the weight into the air, probably 2/3 of the total weight, no surprise
14lb Sniper + 10lb weight: broke before getting the weight into the air, at/inside the Palomar knot
14lb Sniper + 10lb weight: broke before getting the weight into the air, at/inside the Palomar knot again
14lb Sniper + 10lb weight + more saliva and slower/more deliberate knot: got all 10lbs into the air and held it there steady for 20-30 sec, then started pulling up hard on it to add more downward force, caused it to break at/inside the Palomar knot after that
10lb Sniper + 10lb weight: broke before getting the weight into the air, probably 1/2 the total weight. WOW was this upsetting.
I didn't try any more with the 10lb Sniper as I was pretty annoyed at this point. It is possible I would have gotten it into the air but I doubt it.
So, my question is, what's the deal? This fluoro is only 3 months old. It's been kept out of sunlight as much as possible (in a bag 95% of the time). The ONLY thing I can think of, is that, on a canoe trip in June, I had both spools in their plastic boxes inside a canvas(?) pouch on the side of my backpack. This canvas pouch has a zipper and but no ventilation holes. The backpack sat on the floor of the canoe which basically always had a small amount of water in it. My backpack bottom was almost always wet to some degree.
Is it possible that excessive wetness and possibly mild heat (mid-70s) caused the line to weaken significantly? The line was in the plastic box it comes in, so it's not like it was sitting in tons of water, but the pouch it was in was wet a fair amount of time and didn't dry out quickly, so it was probably humid inside the pouch. Could this really cause the line to weaken so significantly?
Needless to say, I feel like I can't trust the line anymore, so I bought some more, and will be keeping it in a hard plastic container away from water, air, and sunlight. But I would still like to know what the heck happened.