For most of my Saltwater fishing I have used 5-turn Nail Knots. This has more bulk, mainly because the mono is thicker, but it a strong knot, rarely slips but is also relatively skinny. If you want to make it a bit slicker you can coat it in Aquasure or similar.
Here in the Malaysian Jungle however I ran into problems with the 5-turn nail knot and had a few slip - mostly on snags, or trying to entice fish out of them, with force, and I don’t wish for that to be my weak link. The weak link to my mind should be the fly knot, not the leader to fly line knot. I think that makes sense!
So about three years ago I tested the welded loops. In fact I was testing Snakehead Leaders to breaking point to see where they would break and with how much force - remember here in the jungle I generally point the rod straight at the fish and hang on. When testing I didn’t want to risk breaking my floating line and instead used an 8WT streamer line from SA - they had kindly sent me a couple for chasing Snakehead in the deeps. I had the hook embedded in a tree stump on one end of the line and on the other end of the line I had it wrapped around a set of luggage scales - or balances? - and was applying a big yank with the boat lodged up against another stump. That was how I discovered that the Streamer 8WT lines I had been sent had a 22/23lb core, which surprised me because I thought 8WTs were typically on 35lb core. Bruce later confirmed that for the sinking lines they need to use thinner diameter and hence weaker cores.
Anyway this also meant that the welded loops that come from factory are good enough to at least 23lbs! And Bruce later told me he had hung 25lb weights off them when he was testing them. *there is a link below where they have been tested to break or tear apart at between 20.5kg and 24.15kg!
You can reinforce the loops but it doesn’t appear necessary - BR uses two ten pound mono whippings for security, I use Danville’s 210 tying thread but only after the welded loops have started to come apart.
One of the questions I had recently, was what do I do when the line has no welded loops? And I do have lines that don’t - for example we make lines that don’t (but we will have them on the next ones). I use typically 6WT lines for Giant Gourami with braided leaders , so that has to be loop-to-looped. So here I do something very simple, and it takes only a few minutes and seems reasonably permanent.
Firstly I strip about 1 1/2 inches of coating off the line’s tip. Then I double this back over the fly line and whip with the 210 thread in three places and superglue the whippings. That has always been enough for me and it’s never slipped. I check it from time to time of course, especially after being “stumped” but it’s easy, straightforward and can be done quite easily on the water.
Bernd however does a much better job of it here, in a step by step:
There is a good discussion covering this and more from a few years back here:
[Graeme links to a test done by Steve O in the Aussie SW forum where he tested welded loops to breaking… “The factory loops tested between 20.5 kg low and 24.15 kg high, which is pretty darn good I thought. Interesting some broken on the main line and some the loop pulled apart at the fused glue joint without the line breaking as such. There was no discernible difference in breaking strain between those that pulled apart and those that broke in this sample size.”]
Here’s another similar method to Bernd’s from Viking Lars, way back from the early days of Sexyloops:
And here is a pervious page from me on knots with links to James’ Instron testing:
Hope you’re having a great day!