Gasket stretching

I’m trying to stretch out a VERY tight fitting neck gasket on a new drytop. I have the gasket stretched around a one-gallon jug (approx 19" circumference). My neck size is 14.5"-15". How long should this take and do I run the risk of overstretching it if I leave it on the gallon jug too long?

I used that same technique. I left my gasket on the “jug” between paddles, and only removed it when I was ready to don the suit; and I did this for about a month. This gave the gasket enough time to relax, AND my brain time to get used to the confining feeling.

Differing opinions
from what I have read here and there some say to cut instead of stretch because stretching causes microscopic tears and weakens the gasket. I had a gasket that was so tight I had to stretch it for days just to try the suit on! The gasket got much thinner after stretching it. After finally stretching it enough to just get it over my head (still felt like I was choking to death), I had to order the next size up (for torso length) which came with a gasket that was a little too big! Why such a vast difference in gasket size between size M and L? I wonder what these companies are thinking. I only have a 13" neck and was shocked that the Med. gasket was so tight. I was afraid to cut mine for fear that I would not be able to return it once it was cut. I only needed to try the darn thing on! If you are sure that the suit fits otherwise, you may wish to cut, or call the manufacturer and see what they suggest. You need to cut one ring at a time to be sure you don’t cut to much. One drysuit manufacturer has a chart of neck size and how many rings to cut off (OSS I think).

I’ve thought about doing that …
… but the manufacturer (NRS) says cutting rings off the gaskets will void the warranty. But I agree about the sizing - the rest of the drytop fits perfectly and the wrist gaskets are fine. I’m afraid I’ll pass out from lack of blood flow to my brain if I leave the neck gasket as tight as it is. :^)

I have a young son who thinks the blood supply to my brain was totally cut off a long time ago but that’s a different thread …

Surely they can’t mean
voiding the warranty on the entire suit - must mean just the neck gasket. If you cut carefully with sharp scissors it should be fine as long as you don’t cut off too much or leave any nicks. I have heard that it is possible to tear the gasket if it is not cut well. I don’t know how often that would happen. Maybe others can chime in on that. My husband had to cut his gasket and it was fine. Really, though, what are these designers thinking when they make a gasket too tight for a 13" neck. Obviously, it has to be cut! Even with stretching for days over a 14" container it was way, way too tight. So, a manufacturer can make a product that has to be altered to fit and they won’t honor their warranty after you alter it? Something is not right there.

Good point, and I think …
… I mis-spoke. I believe you’re right - just the gasket warranty would be void, not the entire drytop.

I am a successful stretcher case, BUT
when I hear someone struggling with a very, very tight gasket, I just say, find the marker rings and trim it.

Regarding rumors about microscopic damage caused by stretching, does anyone REALLY believe that controlled stretching with a bottle only a little larger than my neck is going to cause damage WORSE than that which unavoidably occurs every time the gasket is stretched quite unevenly to get it over one’s head?? That cannot possibly be true.

What we really need is a system where the dealer sizes your neck and wrists in the store, and then the manufacturer makes your garment with gaskets precisely molded, trimmed, stretched, whatever, to your exact dimensions.

Trim it
It’s easy, it takes only a few minutes and your garment will be comfortable immediately. IMO, stretching is a waste of time and may do more harm than good. It DOES damage the seal.

Bogus argument

– Last Updated: Apr-20-08 7:39 PM EST –

If you trim a seal to fit properly, you stress it much less when putting the garment on. If you stretch it, you've already damaged it in the stretching process (you have to over-stress the material in order for it to stretch permanently), then you're stretching and stressing it more on top of that when you put it on. With a trimmed seal, you're stressing undamaged material; with a stretched seal, you're stressing material that's already damaged. Common sense will tell you which one is more likely to be problematic.

If you want to reduce the stress on a seal and make sure that it stretches evenly when you don the garment, simply powder the inside of the seal with talc and it will slip over your head in a heartbeat. When removing the garment, insert both hands into the seal and carefully "walk" it up and off your head. Make sure to be careful with your fingernails, rings, etc.

I thought we had agreed to disagree
on this point.

It should be obvious to anyone that repeated pulling of a gasket over a normal sized head is going to cause more damage than that caused by slipping in a 3 liter soda bottle and leaving it there.

And, since a 3 liter soda bottle is not much larger than my neck, it obviously is not going to damage the gasket more than my just wearing the gasket.

Now, trimming, I grant you, does not make a gasket more likely to be damaged by repeated pulling over ones head.

However, a trimmed gasket imposes force over a narrower area of my neck than does a pre-stretched gasket. I don’t like that. I prefer the feel of a carefully stretched gasket.

The contention of yours which I find both empirically and conceptually unsupportable is that controlled, measured prestretching somehow damages a gasket in a way that pulling that gasket repeatedly over the head does not.

It must gall you that some drysuit
suppliers are recommending stretching over trimming, at least for wrist gaskets.

bnystrom is right…
Trimming is better if you know how to cut a straight line…

Stretching simply prematurely wears out the latex. Think about it…

And when it comes time for replacement

Simply walk into a store that has different sizes on their shelf and try them on until you get one with a snug–not too tight–fit. You won’t need to stretch or cut.


You are both wrong. Your own neck,
and the process of donning and doffing a gasket, provide more stress to a gasket than controlled stretching. Think about it. Do you seriously think gaskets are not subjected to repeated and prolonged stress when used?? And we all know that, if one is lucky enough to buy a gasket that is close to a good fit in the first place, the first ten uses will stretch that gasket further, and make it more comfortable. Do you dispute this?!? Controlled stretching with a large soda bottle is simply a way to accomplish the same thing that normal use would do. Usually it will do that, without shortening the life of the gasket.

Trimming is its own reward. It is a quick way to get an acceptable result. But there is no reason to expect a trimmed gasket to last longer than a pre-stretched gasket.

Think about it. Or, don’t.

Like shoes
You can stretch a shoe somewhat if the fit is a bit tight. But you cannot stretch a size 9 into a size 11.

If the fit is just uncomfortable, stretching will work, and you can use a device or just wear it to break it in. If it is clearly the wrong size, you need to trim it to the point where is is just a bit uncomfortable, and then again you can use a device or just wear it to break it in.

If you have broken it in, and it is still too tight, just remove the rings one at a time. It doesn’t have to be uncomfortable to work.

And here’s another thought
I changed which brand gaskets I use several years ago, because the gaskets that both came with, and are sold as replacements for, my drysuit were blowing out, sometimes after 2 or 3 uses.

So, I bought one from NRS. Put it on the suit 2 years ago, and it’s still in great shape.

Except for one problem…I bought a large (My neck size is listed as a good fit in both medium and large on their sizing chart), and it was VERY comfortable. This past saturday, after being out a ways offshore, I dumped a bucket of fresh water over my head to rinse off. I still had my drysuit on. And water trickled down into the suit past the gasket – it had stretched out far enough on its own that it didn’t seal well anymore.

So now, I am sacrificing a perfectly good gasket and replacing it with a medium.

Cutting can get you in a world of hurt just the same if the gasket stretches too much after. It should be just slightly uncomfortable new, or it won’t stay tight enough.


Sorry G2D, but you’re just plain wrong
What you either don’t understand or refuse to acknowledge is that the only way to get latex to stretch permanently is to stress it past its yield point. That DAMAGES the latex, whether you want to admit it or not. Your “controlled stretching” concept is pure bunk. All you’re doing is prolonging the stress on the material until it eventually yields. The fact that the damage occurs over a period of weeks doesn’t change the fact that it’s still damage. That’s different than the short-term, albeit higher stresses that occur when donning or removing a garment. While it’s obviously possible to damage a latex seal if you’re careless, it can handle higher, short-term stresses just fine. Otherwise, seals would fail in short order after just a few uses.

I acknowledge that you have a valid point about contact area, but it’s not an issue for me - and probably not for most people - and IMO it’s not worth weeks of suffering with a too-tight neck seal for the minor benefit it may provide. It’s also not as if a trimmed seal has a tiny contact area. My own seals contact my neck for at least an inch all the way around.

As I’ve said before, do whatever you like on your own garments, but don’t make up nonsense to justify it or try to convince others that your method is somehow better for the seal.

I leave mine comfortably snug…

– Last Updated: Apr-23-08 7:40 AM EST –

...after trimming. That ensures that as the seal ages and loosens (due to the effects of UV, sunscreen, sweat, etc.), it will still seal properly. I find that seals typically only last 3 years if they're used much, regardless of what you do.

Your correct
that latex gaskets vary in the type of latex used and they seem to wear differently also. Glad to hear that you found a latex gasket that works better.

Sea Kayaker Magazine will have a do-it-yourself article, in their august issue, that will allow you to replace the latex gaskets with a neoprene gasket that seals just as well as latex and is much more comfortable. Hang in there.