Neoprene Neck Seal

[lloydwatkin]

Right, my drysuit arrived this morning with a new neoprene neck seal fitted (and smelling nicely of glue ).

I've never used a neoprene neck seal before so was wondering how I 'work' it? Latex you plop on, look for kinks and done. The neoprene seal seems fairly loose. I've tucked the seal back on itself but it's still relatively easy to get my finger down the front of the seal.

Am I doing something wrong? (Fairly urgent as I'm diving this weekend ).

Cheers, Lloyd.

[Ant P]

Sounds like you are doing the right thing. Perhaps your neckseal is too loose. Only you will be able to tell that though - it all depends on what you mean by relatively easy to get your finger in.

Cheers, Ant

[wilbo]

Originally Posted by lloydwatkin

Right, my drysuit arrived this morning with a new neoprene neck seal fitted (and smelling nicely of glue ).

I've never used a neoprene neck seal before so was wondering how I 'work' it? Latex you plop on, look for kinks and done. The neoprene seal seems fairly loose. I've tucked the seal back on itself but it's still relatively easy to get my finger down the front of the seal.

Am I doing something wrong? (Fairly urgent as I'm diving this weekend ).

Cheers, Lloyd.

If the seal has been sized correctly then it will be fine. Don't forget that the air pressure under that flap of neoprene is what helps push the material against your neck..

just make sure you have a minimum of half an inch turned over inside.. an inch is better

[PapaBear]

I know when I had mine fitted it took some getting used to.

When you put it on you want to fold the smoothskin exterior back in on itself so it is touching your neck. I like to fold a good half or so in so that I have a lot of neoprene in contact with the skin to get a lot of seal.
Quick way to test it is to put your drysuit on and empty out the air from your dump (time to double up) and just check none is finding its way out through the neck.

Not the best but I hope it helps

[Woz]

My neo neck seal is so baggy you can stick a finger down the front without touching neoprene or skin. Still seals though. How? Not sure. Must be magic.

[lloydwatkin]

Originally Posted by wilbo

If the seal has been sized correctly then it will be fine. Don't forget that the air pressure under that flap of neoprene is what helps push the material against your neck..

just make sure you have a minimum of half an inch turned over inside.. an inch is better

I think on my initial trial I was folding way too much back down so the lower part of it was already flaring outwards (I used to wear latex as far down my neck as possible). Wearing it higher up and only holding back about an inch worked much better and the seal was much tighter. Head back it still seemed a little loose at the front but I think it'll hold.

Originally Posted by Ant P

Sounds like you are doing the right thing. Perhaps your neckseal is too loose. Only you will be able to tell that though - it all depends on what you mean by relatively easy to get your finger in.

It was pretty easy, effortless, but I think I've found the cause (see above).

Originally Posted by PapaBear

When you put it on you want to fold the smoothskin exterior back in on itself so it is touching your neck. I like to fold a good half or so in so that I have a lot of neoprene in contact with the skin to get a lot of seal.
Quick way to test it is to put your drysuit on and empty out the air from your dump (time to double up) and just check none is finding its way out through the neck.

Managed to self-don my drysuit just now (sweaty work!) and wore it further up my neck and folded less in on itself. Plumbed myself in quickly and hit the air with dump closed. Gave a good squeeze and nothing came out from the next seal, so I'm happy with it now.

Thanks for the info, Lloyd.

[nigelH]

Originally Posted by wilbo

Don't forget that the air pressure under that flap of neoprene is what helps push the material against your neck...

I keep hearing people say that but it's so obviously not true. No difference in pressure.

Neoprene seals work just like latex seals by the elasticity pulling them snug up against your skin. However the fold means you effectively have two rings with differing tensions. The outer one presses the inner neoprene into the depressions and softer parts of your neck improving the seal. Latex, having negligible thickness, cannot perform this trick. Neoprene tends to work best for those of a chubbier build where latex's point-to-point rubber band style would leak on the softer bits but on skinny runts like me it snaps tight over our 'outstanding' ligaments.

The real advantage of neoprene, if it suits you, is just what the OP described: a looser, more comfortable fit can be just as dry as a tight latex.

[wilbo]

Originally Posted by nigelH

I keep hearing people say that but it's so obviously not true. No difference in pressure.

Neoprene seals work just like latex seals by the elasticity pulling them snug up against your skin. However the fold means you effectively have two rings with differing tensions. The outer one presses the inner neoprene into the depressions and softer parts of your neck improving the seal. Latex, having negligible thickness, cannot perform this trick. Neoprene tends to work best for those of a chubbier build where latex's point-to-point rubber band style would leak on the softer bits but on skinny runts like me it snaps tight over our 'outstanding' ligaments.

The real advantage of neoprene, if it suits you, is just what the OP described: a looser, more comfortable fit can be just as dry as a tight latex.

How could I argue with a scientist..

You forgot the "and now for the science bit.." before your explanation..

[Woz]

Originally Posted by nigelH

I keep hearing people say that but it's so obviously not true. No difference in pressure.

Yes there is. Otherwise none of the air in your suit would migrate upwards. There is a small head between your dump valve and your neck of about 6", or the pressure at the bottom of a pint glass.

Assuming you drink pints. I had you more of a "half a mild" man.

[nigelH]

Originally Posted by Woz

Yes there is. Otherwise none of the air in your suit would migrate upwards. There is a small head between your dump valve and your neck of about 6", or the pressure at the bottom of a pint glass.

The front of my neck seal is normally below my dump valve and the back of my neck is above it.
Are you saying neoprene seals should leak if you go head down??

Anyhow you can't close a seal with pressure like that. The pressure at the open edge (skin to seal) is equal to the pressure across it. It is like arguing that a sheet of paper is pinned to my desk by the pressure of the air above it.

Assuming you drink pints. I had you more of a "half a mild" man.

Neither.
I've been on the wagon since 1968.