Neck seal too tight?

[hfx]

I'm replacing a silicone neck seal and trying to figure out if the stock size is too tight. It feels pretty snug and does seem to be restricting some blood flow, leaves ring marks on my skin when I peel it back, but I can breathe ok.

The seal I'm replacing had 2 rings removed, but that was for the original owner. I dived it about 4-5 times before it failed catastropically and there were some mystery leaks, so I'm wondering if I should try the uncut version before trimming it. Or is this too tight and I should take it down a ring? Neck size is 15.5-16". Thanks for any insight!

 

[lexvil]

It looks to tight but I always dove them before trimming because one small mistake on silicone leads to catastrophic failure more often than not. I no longer use silicone neck seals since buying a waterproof neoprene neck seal, it the way to go in colder water. Don’t know if you went today but breakwater was 60 to 63° weird but it can happen.

 

[Zef]

The silicone neck and wrist seals come in 2 sizes, standard and small. Are you sure you neck seal is not the "small" size? My neck size is between 17.5 and 18 inches and I have not needed to cut my silicone neck seals down.

If you do decide to cut yours, as @lexvil mentioned, one small mistake can cause the seal to split. When I was dealing with latex seals as a whitewater kayaker, I had achieved very good results trimming my seals by clamping them between two 1-inch by 1/2-inch boards that were a couple feet long, and then using an ultra sharp scissors, cut along the board to get a straight, even cut without any nicks....the nicks cause a stress riser when the seal is stretched, which becomes the nexus for the seal to tear.

Double check what size you have first, though.

Good luck.

-Z

 

[hfx]

The silicone neck and wrist seals come in 2 sizes, standard and small. Are you sure you neck seal is not the "small" size? My neck size is between 17.5 and 18 inches and I have not needed to cut my silicone neck seals down.

If you do decide to cut yours, as @lexvil mentioned, one small mistake can cause the seal to split. When I was dealing with latex seals as a whitewater kayaker, I had achieved very good results trimming my seals by clamping them between two 1-inch by 1/2-inch boards that were a couple feet long, and then using an ultra sharp scissors, cut along the board to get a straight, even cut without any nicks....the nicks cause a stress riser when the seal is stretched, which becomes the nexus for the seal to tear.

Double check what size you have first, though.

Good luck.

-Z

It's the replacement seal that came with an ML size Waterproof suit, so I would think it's the regular size. Are they labeled somehow?

Edit: Unstretched, it's about 3.5" across, so a minimum neck size of 11" or so, suggesting it's the Regular size.

I'm not sure I follow your method, are you pressing it flat folded between two slats? I was going to gently stretch it over a plastic cylinder (like a Clorox wipes container) and cut it along the line with a new box cutter blade. Is that not a good idea?

 

[Zef]

It's the replacement seal that came with an ML size Waterproof suit, so I would think it's the regular size. Are they labeled somehow?

Edit: Unstretched, it's about 3.5" across, so a minimum neck size of 11" or so, suggesting it's the Regular size.

I'm not sure I follow your method, are you pressing it flat folded between two slats? I was going to gently stretch it over a plastic cylinder (like a Clorox wipes container) and cut it along the line with a new box cutter blade. Is that not a good idea?

Stretching over a container like you suggest will work, but you have to be extremely careful since the material is stretched and the creation of a stress riser can cause it to split while you are cutting it.

With my method, you lay the seal flat and sandwich it between two pieced of wood....then cut cleanly along the wood using it as a guide to keep your cut straight and clean...I suppose you could use a box cutter with a new blade to cut along the wood. The benefits are as follows:
1. You have a guide to run your cutting implement against
2. The wood protects the side of your seal you are not cutting from your sharp instrument so there is little to no chance of slipping and making an erroneous cut,
3. The seal is not under tension (stretched) so it is not going to spontaneously self-destruct. If you find you don't have the cleanest cut possible, you can unclamp and slide a bit more seal through and cut again, without fear of things going from zero to destructo in the blink of an eye.

Either way will get the job done.

Another suggestion is to stretch your seal onto a container that approximates the diameter of your neck...then leave it a few days. The seals tend to relax (stretch out?) a bit with use...so if you think your seal is the standard size and not the small size, then stretch for a few days and dive it if you can.

The worst thing that could go wrong is the pressure from the seal against your carotid artery could cause you to pass out. Put your suit on in your living room and wear it while sitting on the sofa (so you have a soft landing ) and see if your body can tolerate it without ill effect. If you can pass the living room test, then dive it a couple times. If it is still an issue, then cut it.

-Z

 

[hfx]

Stretching over a container like you suggest will work, but you have to be extremely careful since the material is stretched and the creation of a stress riser can cause it to split while you are cutting it.

With my method, you lay the seal flat and sandwich it between two pieced of wood....then cut cleanly along the wood using it as a guide to keep your cut straight and clean...I suppose you could use a box cutter with a new blade to cut along the wood. The benefits are as follows:
1. You have a guide to run your cutting implement against
2. The wood protects the side of your seal you are not cutting from your sharp instrument so there is little to no chance of slipping and making an erroneous cut,
3. The seal is not under tension (stretched) so it is not going to spontaneously self-destruct. If you find you don't have the cleanest cut possible, you can unclamp and slide a bit more seal through and cut again, without fear of things going from zero to destructo in the blink of an eye.

Either way will get the job done.

Another suggestion is to stretch your seal onto a container that approximates the diameter of your neck...then leave it a few days. The seals tend to relax (stretch out?) a bit with use...so if you think your seal is the standard size and not the small size, then stretch for a few days and dive it if you can.

The worst thing that could go wrong is the pressure from the seal against your carotid artery could cause you to pass out. Put your suit on in your living room and wear it while sitting on the sofa (so you have a soft landing ) and see if your body can tolerate it without ill effect. If you can pass the living room test, then dive it a couple times. If it is still an issue, then cut it.

-Z

Ok, thanks for clarifying that and all of the advice in general.

The only issue I can see with the wood method in my case is that the Waterproof seal is conical, so it forms an arc when folded flat. To get around that I'd have to stretch the sides which may defeat the purpose. Or is there some way to get around that with this method?

I did try to stretch it on a larger can around my neck size for a couple days, but it didn't seem to help. I've worn it for about an hour at a time without the suit - I never passed out but it didn't feel great, hence the ongoing dilemma. I've read elsewhere that your neck is compressed underwater so it may be more comfortable while diving.

At this point I might install it and try to dive it, not sure how else to go about this except cutting one ring down.

 

[Zef]

Ok, thanks for clarifying that and all of the advice in general.

The only issue I can see with the wood method in my case is that the Waterproof seal is conical, so it forms an arc when folded flat. To get around that I'd have to stretch the sides which may defeat the purpose. Or is there some way to get around that with this method?

I did try to stretch it on a larger can around my neck size for a couple days, but it didn't seem to help. I've worn it for about an hour at a time without the suit - I never passed out but it didn't feel great, hence the ongoing dilemma. I've read elsewhere that your neck is compressed underwater so it may be more comfortable while diving.

At this point I might install it and try to dive it, not sure how else to go about this except cutting one ring down.

I see from the picture in your first post that you have a Waterproof brand neck seal...they have that baffle in them that gives them a bit of a weird shape, I can see how this might be an issue with sandwiching the seal between the wood slats.

If you decide to cut a ring off with it stretched over an obeject/container, just don't stretch much for the cutting operation...you want it to maintain a good round shape when cutting but you want it under the least amount of stress possible to get the job done.

Oh, and use a new blade in your box cutter.

-Z