Line strength testing...

[gregorjim]

About ten years ago all the west coast beach fishermen were wondering about all the new Mono & flourocarbon lines on the market... I had purchased a new #30 pd scale with a plastic stopper to show the top weight when lifted..I started testing everyones lines ( about 3' each sample)..Using a vise to hold the scale, I attach one end to a duolock snap with a 100% Palomar knot...On the other end is wrappped about three rolls on a wood dowell...I would slowly pull till the line broke...I did this test at least six times to get a good average... You must remember to moisten ( saliva ) on the knot ,as it makes a tremendious difference in poundage tests...There are no sharp edges with this process while testing...You can test many knots & see the differences each one produces... Reg mono is stronger than Flourocarbon , but Flouro is more abrasive proof than mono....I also found the Triple surgeons knot to be 100% , rather than the blood knot which is only about 70%....This is all i use for making fly leaders now... I tend to use P- line which tested the strongest....BUT after using a Micrometer to test diameters of line , found that alot of strong lines were actually thicker than others, which justified why they tested higher than the smaller lines.. I still use P-line as it works for me...Remember Saliva first ...It works better than dry knots....Think i had way too much time in the off season...But It improved my lines , leaders & makes me more confident in my equiptment...Try it....Jim

[sprattoo]

This is similar to how I come up with a breaking point / lb test on my furled leaders.
Of course the fresh water lines are a lot less hassle, since the lb test is so much lower. I the end of a furl I have 3 loops, so I just multiply the breaking point x3, for my furling mono, or thread, or whatever.

I have found that some line actually break much higher than their ratings, some spot on, but only like one broke below the mfg lb test rating... and that was so close on each break, that it was negligible.
Who woulda known that everyone was being honest about their breaking points?

[gregorjim]

Spratto...Not sure what knot you're using for loops...You can check it with a scale....If you use perfection loops =70-80% as apposed to surgeons loop _ 100%...It makes a big difference same for tapering leaders..I also use the Palomar =100% for flies,,Or a Kreh loop 90 -100%...Remember Fluorocarbon is easier to break than mono , so improving with stronger knots.will help..Also did a test with braided loops on fly lines with the same scale system & the #50 test braids never broke..The fly line broke at 27-31pds each time...This was loops done with Three #10 mono ten wrap nail knots holding the loops on...Not with the shrink tube set-up...These failed almost every time .Always coat the nail knots with "Knot Sense " to protect them...
Just my 2 cents ? Jim

[zimno1]

excellent job. as scientific as it is the breaking point of knots attatched to fly line always perplexed me. i would only use a nail knot (always knot sense) but have all to do than to experiment like this. wtg jim are we gonna do a fly swap here?