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Stretching out gaskets

Posted: Sat Apr 27, 2013 1:18 am
by maggiepowell
What can I use to stretch out the latex gaskets on my dry top? I thought I my try that option before selling it or trimming the gaskets. Any advice?

Re: Stretching out gaskets

Posted: Sat Apr 27, 2013 6:40 am
by Regud
Soup cans for the wrists and a coffee can for the neck.

Re: Stretching out gaskets

Posted: Sat Apr 27, 2013 7:26 am
by philllll
I use plenty of 303 to condition the latex... i think that's key.
and a football in the neck.

Re: Stretching out gaskets

Posted: Sat Apr 27, 2013 8:51 am
by okieboater
For what it is worth, I used to do the stretching routine but don't any more.

I am sure there are some folks with the back ground on what happens when materials are stretched or over stretched, but my memory is long gone on technical details from the north avenue trade school. (Hint for Eric to jump in here!)

My reasoning is latex has a certain amount of "stretch" built into the material.

If you exceed this built in limit, you will increase the probability of breaking instead of stretching.

So, I trim my gaskets to fit and use plenty of 303 as mentioned by phillll.

I don't like a fit so tight it cuts off blood circulation either. I can put up with a slight amount of leakage long as I can enjoy plenty of blood circulation for comfort and keeping from turning blue due to over-tight neck gaskets.

Having blown a neck gasket one morning (after a cold night on the middle fork) I like my gaskets to have plenty of stretch factor left even if cold.

Re: Stretching out gaskets

Posted: Sat Apr 27, 2013 9:12 am
by rugger
If you do decide to get a new drytop, I just got a Stolquist drytop w/ neoprene neck gasket (latex wrist) and I'm loving it!!!

Re: Stretching out gaskets

Posted: Sat Apr 27, 2013 11:16 am
by RomanLA
I read somewhere that you shouldn't stretch them for more than a couple of days and then trim them for the rest of the fit. I really wish you could trim wrist gaskets too. Mine are insanely tight right now!
okieboater wrote:Having blown a neck gasket one morning (after a cold night on the middle fork) I like my gaskets to have plenty of stretch factor left even if cold.
I blew a wrist gasket on the last full day of whitewater in the grand canyon. I braced into a big lateral and water went in one sleeve and all the way across and down the other! lol

Re: Stretching out gaskets

Posted: Sat Apr 27, 2013 12:25 pm
by okieboater
RomanLA

Man I trim a bunch off my Kokatat neck latex and wrist till I get a snug but not tight fit.

Only difference is on the wrists cut off between 1/16 and 1/8th inch width (closer to 1/8th for me) at a time. Latex Wrists are conical and a small cut goes a long way. So cut off a little bit at a time and check fit after each cut. Like I posted, I would rather have a few drops of water leaking thru as opposed to my hands going numb from lack of blood flow.

Re: Stretching out gaskets

Posted: Sat Apr 27, 2013 2:27 pm
by Eric Esche
OK Dave, Here I jump. Maybe farther than wanted.

Okieboater may not have been a Textiles major at Georgia Tech, but he got it right. Neat, VERY even trimming with sharp scissors is the preferred method for fitting a latex seal as opposed to stretching. Even the slightest burr or nick can develop into a split eventually. If you cut the latex seal treat it with Dupont 303 all over, but particularly on the cut edge. GO SLOWLY in trimming. You can not undo a cut in latex seals and it can get expensive replacing seals. I would recommend to cut away no more than 1/8" at a time, and then wear it with a hose nozzle on full stream from 2 foot away to see if it leaks in 2 minutes vs how tight it is for 20 minutes. There are special seal cutting scissors that are supposed to ensure a very precise square edged cut, but they are expensive, hard to find and order, and not worth it in my opinion unless you are a production facility with high volume government contracts. Most production facilities use Wiss textile hand scissors and throw them away rather than trying to resharpen them when dull as most areas do not have quality resharpening companies near by. Dull scissors are more dangerous than a dull knife (especially in some high speed textile operations).
Barber shears work well for trimming latex seals, but lubricate them with DuPont 303, not oil.

In plain English, without getting into polymer science, stretching will weaken the latex gasket shortening it's life, if not weakening it to failure. Older latex gaskets do not like to be stretched at all. They also do not like sunblock (except DuPont 303), bug repellents, UV exposure, sharp edges or objects, abrasives, detergents, oils, and heat. (Have seen folks destroy a latex gasket by warming it up with a hair dryer to stretch it thinking that they could soften it, and have known some raft guide seal installers whose latex seal replacements never seem to last long find out that warming the seal to accelerate the curing time of the adhesive was degradating the latex.- won a $200 bet when I proved that to his satisfaction. HE was installing them in a barn in winter due to the ventilation issues with the adhesives and his wife. He also had other problems with moisture, contamination, consistant solvent concentrations, aged improperly stored adhesives, etc)

The slickness provided by DuPont 303 can also make the gaskets easier to don and doff, particularly over long hair. IF you ever think you got sunblock or bug repellent on a seal, wash it ASAP with a very dilute mild detergent (Dawn or baby shampoo) and then retreat with DuPont 303. Particularly retreat with DuPont 303 before putting away for seasonal storage, and then in a cool dark place with the seals in their normal shape as much as possible. I hang my suits in the off season on wide dive suit hangers sucessfully. Only gaskets I have had to replace were on suits I bought used. (Thank you again Tim Muse for the excellent installation work) Have seen several horror stories first hand of folks who did not rinse and retreat their gear before storage, only to pull it out the next time and have all their gaskets dissolved into a tacky unuseable mess - reason I resisted getting a drysuit for so many years. Other mistakes I have seen destroy latex seals were folks thinking that 3in1 oil or teflon gun oil or spray would work for Dupont 303, because they did not have any. If you retreat your breathable fabric for water repellancy, keep the treatment away from the latex seals. You used to be able to find replacement seals that are made from a slightly thicker "commercial use" latex at OS Systems, but my opinion is still pending on if they are worth the extra cost. Tim did a great job installing them for me and they are lasting.

Other drysuit issue to remember is to use a good quality zipper wax stick on the zipper and not candle wax or sealing parafin. ( you can find this most easily at a dive shop that sells and services drysuits or on line.) Periodically wash the zipper with flowing water and a nail brush if it appears that you are getting dirt or grit like sand or clay. Too much wax can attract dirt and grit. I know folks who swear by beeswax for zippers, but it atracts dirt and grit worse than zipper wax.

If you help teach or practice rolls in a pool with a chemical system, rinse and retreat. Some pools are worse than others and it is far cheaper to rinse and retreat than replace. I have never had to worry about using chlorinated city water for rinsing as I have always been on a well with filtered UV treatment systems since I have had dry gear or wet gear, so I do not know for sure if this is an issue. Rule of thumb I was told in school was if you can smell it (chlorine or sulfur), you do not want to rinse with it.

Other technique for neck gaskets is a divers neck ring, not found as much anymore. It is a form of stretching in that a hard plastic hinged neck ring is inserted underneath the latex neck seal to reduce pressure on the throat and cervical discs until just before immersion, like for divers going out to sea on a dive boat already dressed in their non breathable dive suits. I tried one in desparation when I started having degenerative disc disease figuring it was not stretching the latex that much for that long, but it did not work for me. When I tried to use it on the river and wait until the last minute to slip it out, then I had problems getting a smooth unwrinkled neck seal fast enough and when I retreated my neck seal, it slipped out unplanned if I turned too much and then there was the hassles of getting out of my pogies to fix everything. Gave it to a friend who laughs and says it is great when he can remember to bring it.

YMMV and you can take this with as much windage as you like.

Eric Esche

edited once for spelling, which I consider fairly good for only having had 30 minutes sleep last night. Beginning to think I need to take up a second career as a weather forecaster with my knee and shoulder repairs, the DDD and arthritus. Rain gauge says we got 1.9 inches of rain last night and I have not had any alcohol or a pain killer in a week now, but planning on going sea kayaking on Monday.

Re: Stretching out gaskets

Posted: Sat Apr 27, 2013 3:06 pm
by okieboater
Now you know the difference between a IE and TE!

Well explained, one that Cowper would agree with.

dave

Re: Stretching out gaskets

Posted: Sat Apr 27, 2013 4:32 pm
by RomanLA
Eric Esche wrote:Other technique for neck gaskets is a divers neck ring, not found as much anymore. It is a form of stretching in that a hard plastic hinged neck ring is inserted underneath the latex neck seal to reduce pressure on the throat and cervical discs until just before immersion, like for divers going out to sea on a dive boat already dressed in their non breathable dive suits.
I remember paddling with someone that had a ring made out of tygon tube with something to join the ends together.

I bought some $20 fiskars seamstress scissors that I only use for trimming gaskets. Dave...I'm way too chicken to trim my wrist gaskets. The lack of rings spooks me.

From the Kokatat site...
The neck gasket on your Kokatat dry suit is designed to be trimmed (Kokatat wrist gaskets are not designed this way). The neck gasket should fit tightly without being too constricting. If stretching the gasket over a form does not increase the comfort, trim the gasket one ring at a time until it is comfortable but does not allow water in when you are swimming (see gasket trimming instructions). Consult your dealer or Kokatat customer service if you have any questions, and remember, cut once and test before cutting again!

Re: Stretching out gaskets

Posted: Sat Apr 27, 2013 5:13 pm
by maggiepowell
Wow, it's going to take me days to read and comprehend all this info. Right now, I've opted for the stretching method since I am not comfortable trimming just yet. But I don't think anything I am using for stretching is going to over-stretch them.

Thanks for all of the info though. Lots to learn about river gear, who knew?

Redwonder

Re: Stretching out gaskets

Posted: Mon Apr 29, 2013 4:33 am
by kayakmamma
rugger wrote:If you do decide to get a new drytop, I just got a Stolquist drytop w/ neoprene neck gasket (latex wrist) and I'm loving it!!!

I have bought two of these and like them but find them to only be SEMIDRY

Re: Stretching out gaskets

Posted: Mon Apr 29, 2013 6:33 pm
by rugger
Your neck just isn't big enough!! :poke2:

Re: Stretching out gaskets

Posted: Thu May 02, 2013 7:27 pm
by JB2012
Maggie,
Contact Painter Bob. He trimmed my brand new Kokatek (sp?) dry suit on a wood fence at High Bank, with a razor-knife,
two years ago. No problems!

JB