TUF LINE XP 50Lb - testing

[fava]

Hi all, i recently bought a 300yard spool of yellow TUF LINE XP braid from ebay.

i wanted to see the limit at which the braid fails.

First test:
-figure of 8 loop on both ends
-one end, was the bucket to put the 2.5 litre water bottles
-the other end was a screw driver holding the top loop.
-started loading the 2.5l water bottles in steps,
-the 50lb braid failed at 4 bottles, i.e 10kg

Second test:
-Uni knot at both ends,
-bottom uni knot holding the same bucket, (plastic grip part)
-top uni knot held around the screw driver (rubber grip handle)
-started loading the water bottles,
-after 5 of the 2.5litre water bottle(i.e. 12.5 kgs), i started loading using the 0.5 litre smaller ones.
-the braid failed at 15.5kg, but still at the uni knot.
(most probably it is still capable of withstanding more weights)
In this case, the braid failed at 70% of the breaking strength (50lb).

Could someone specify a better knot than the Uni knot?..
Other suggestions and comments are more than welcome.

Andrea