Am I tying this knot correctly? Am I using the right line?

[SaltyFrog]

However tight I pull these they always comes loose after a few dives.

I'm using cave lines but it feels to me it's too smooth?

Should I use other kind of line? Or different type of knot?
Or maybe I should just switch to a zip tie.. Any downside to that?

Thanks!

 

[tbone1004]

righ tline, wrong knot, and not finished properly. This is GUE's take, I do mine a little different in terms of how it starts, but they are all finished the same way

 

[Divin'Papaw]

It tie a square knot on each side. I also burn the ends and also put a good dab of waterproof superglue on the knot and let it cure fully. It sets in the knot extremely well. I've never had one come undone and I have some that are years old and see regular use.

 

[lowwall]

Knot is definitely wrong. Not enough loops and I think you have a granny instead of a square knot.

Here's another video:

And another:

I've always used the first method. The difference between the two is Simply Scuba ties a square knot on both sides. I've never had one come undone, but I think I'll retie at least my lights that way for redundancy.

 

[uncfnp]

A bit of heresy!

Hose Clip Retainer

 

[Divin'Papaw]

A bit of heresy!

Hose Clip Retainer

Not heresy as this isn't the DIR forum. I HAVE tried those and hated them. I prefer old skool cave line. I have a few I should put up for sale! I know some people love them. To each their own.

 

[tursiops]

A bit of heresy!

Hose Clip Retainer

These are fine on hoses. But on a light -- like the OP is doing -- I prefer a proper tie and knot.

 

[Marie13]

A bit of heresy!

Hose Clip Retainer

I've used those, but I also tie bolt snaps on with thin bungee. It's never failed me. Cave line never worked after many tries so I just stayed with what worked.

 

[SaltyFrog]

The problem on lack of loops is because the hole on the light is too small.
It only allows for 1 thread.

 

[SaltyFrog]

It tie a square knot on each side. I also burn the ends and also put a good dab of waterproof superglue on the knot and let it cure fully. It sets in the knot extremely well. I've never had one come undone and I have some that are years old and see regular use.

Questions..

Which glue do you use?

And if you superglue it, then it's ok to use Zip tie?
I thought the reason to use line is because it's cut-able in an emergency. Are glued knots also cut-able?

Thanks!