surprising knot failure

I was fishing under the mangroves in Florida's Intercoastal waterway and I lost two quality fish to knot failure.  this was shocking to me as I have knot lost fish, and lures to knot failure in years.  I use palomer and trilene knots, I'm not sure which I had tied that failed.  but what was different this time than from past times is that I was using a 25 lb. fluorocarbon leader to lure connection.  I have zero experience with leader this heavy so I can only assume that this was the problem.  I did notice on the palomer that it didn't seem to sit right so I started using the trilene knot, but that didn't look quite the same either.   I have checked and double the knot tying technique and both were tied correctly. 
I'm asking those of you who tie heavy flouro or mono to lures what knot you use for no slip success.

The Trilene knot is by far the knot I use the most for terminal connections.  But what I've noticed with the Trilene knot with fluorocarbon is that it can slip.  This is especially true when I'm tying around something larger than the eye of a light-wire freshwater hook, such as around a split ring or large saltwater hook.  In these cases, I'll do an "improved Trilene knot", where I take the tag end and after bringing it through the two loops, bring it up and through the "third" loop just like you'd do with an improved clinch knot.  I haven't had this knot slip on me yet, and I've been using it for a few years now.

I can't speak for the palomar, as I rarely ever use it.

The San Diego is a great knot but is a bit bulky

I typically use the palomar exclusively for braid but I was taught  one tip on a long range boat.

Tip:  The two pieces of line that travel through the eye of a Hook, swivel, etc, MUST NOT CROSS each other. 

Always remember to use plenty of lubrication (spit) when you tighten and pull from the tag end not the main line. 

Hope this helps

PS last tip:  inspect your knots after you tie them.  If your not 100% confident, cut it off and tie again

 

When I'm lazy, I use palomar.  For most part with heavier line application, I tend to use san diego jam knot.

Gotta keep everything square and inline when snugging them up...I am a fan of the uni knot, From AK to CA to FL I've rarely been disappointed...usually only from my own fault (tying error). The SD Jam and Palomar are solid as well...I think a lot comes down to taking the time to tying one right and smooth.

Great replies here, thanks.
I agree.  I'm pretty sure it was the trilene that failed once and the palomer once.  Both should hold if tied properly but because of the heavy stiff line they were not.   After reviewing videos I realized that I was not careful enough to make sure the knots were laying correctly atop the eye of the lure. I've been practicing and found that using more line helped, as well as making sure none of the loops were caught alongside the eye rather than on top.
I never heard of the san diego knot but will you tube it and check it out.
thanks again.

Can't find the one I use?! I pass line threw hook. pull up, pinch together, pull tag end down into a loop and hold with main line, then tag end held out , swing bait around tag end 5 to 7 times, pass tag end up threw loop made on top (pinched in fingers with main line). Wet and pull down. Can break if not done right. I tug HARD on finished knot to test. if good, won't break or undo ever... Don't know what it's called....

I'll be damned, never knew it was called a San Diego knot! http://www.animatedknots.com/sandiegojam/#ScrollPoint It's the knot my grandfather taught me to tie (he lived in LA and loved to deep sea fish, makes sense.) I never even knew any other knot until I taught myself the Trilene (which is pretty close to the San Diego knot) and the Palomar.

My trick is, with the Palomar, I throw another half-hitch (or two) behind the knot just to keep the tag end from slipping, especially with braid.

Well, I tried that san diego knot and I better hope my palomers are tied properly because my old arthritic hands just refuse to do that 'reverse' thing. Hell I have enough trouble going forward..........LOL......Looks like a knot that can be counted on though, for you young'uns (under 60)  YeeeeHawwwwy'all

Fluorocarbon slips.  A lot.  Leaving a slightly longer tag end might help.  Or get a bottle of super glue and use the fly fishing trick of putting a drop in the knot...

I use to like the Trilene knot but stopped using it because it was slipping under heavy loads.  I switched over to the San Diego Jam Knot and like it a lot. 

The San Diego jam knot is my go to.  I will tie perfection loops for live bait, light line applications and fly fishing.  Spangler knot for stealth and heavy line applications.