remove seamtape/neck gasket replacement

-- Last Updated: Apr-23-08 7:41 PM EST --

Tips? Techniques?

Need to replace neck gasket in a suit with a sewn in/seam taped neck gasket--over three seasons the stretching and various chemicals have resulted in many micro tears and the gasket being permenently stretched too much (Dry suit's not too dry anymore when playing upside down.). I'd like to convert to a Kokatat Aquaseal style attachment. I'd like to attach the new neck seal to the fabric and not the base of the existing neck neck gasket, so I need to have all of the gasket carefully removed. Otherwise, if I just cut the fabric at the base of the gasket, the gasket base/fabric will not be of the same circumference which causes all kinds of problems.

I would think that a medium iron would release the heat activated glue of the seam tape?

Tedious job but possible if patient
Go to Kokatat’s downloadable instructions and get the instructions for the neck gasket replacement.

Directions are there for both with and without the gasket replacement tool.

You will need a seam ripper to remove all the stitches prior to stripping off the old gasket.

It is slow and tedious but possible if you are patient.

My preference is to glue to the old gasket for the first replacement and then when it needs another, I send it in for Kokatat to do.


I would think that an iron
set at medium high would work well for removing the tape. Thats the setting I use to release the glue when I remove a latex gasket from a suit. To apply heat tape I set the iron to the high setting, so if it doesn’t want to release easily, just turn the iron up a little more. It’s a good idea to remove all of the the old gasket. I have heard stories about people that have had a new gasket separate from their suit because the old gasket ring fell apart. Removing old gaskets is a slow process, so give yourself some time. Aquaseal works great for adhering the new gasket, without any sewing or heat tape.

Heat gun.
Hair dryer isn’t quite enough, but a heat gun to warm up the gasket and gently pulling will release the old gasket. I’ve never glued to the base of the old gasket. It’s pretty easy to fully remove gaskets. I just cut the stitching as I go and pull the gasket away from the cloth while heating. Some of the thread will remain in the fabric and covered by the seam tape.

Thanks, guys.

– Last Updated: Apr-24-08 1:11 AM EST –

I called Rainy Pass Repair and found out that their seam tape 'iron' is set to 320 F. From what I could determine with a bit of research, most home irons are at 325F on the cotton setting. I tried 'wool' and that didn't do it--figured I'd inch my way up the thermometer. 'Cotton' worked well. Heat up and pull off a couple of inches of seam tape at a time being very careful to keep iron away from suit fabric as much as possible. Then carefully use a seam ripper to cut the stitching and finally separate the gasket from the suit. Rainy Pass uses 'Cotol' (probably McNett's 'Cotol-240') to get the remaining seam tape adhesive off the fabric. The new gasket (same man.) is one size larger and has a larger 'base' diameter, which gives me more suit fabric/latex gasket of the correct circumference to Aquaseal together and a little more 'play' room which is good. Kayak Academy's neck gasket tool (for Kokatat, but a nicer version than what Kokatat sells) should do the trick to get it all together and converted to a field fixable style like Kokatat. Did a new wrist gasket today with Kokatat's kit. Do the neck gasket tomorrow. Thanks again.

“Cotol” is just overpriced toluene
You can get a pint of toluene at a hardware store for less than the cost of the tiny bottle of Cotol.

Thank you! Another great tip.
Probably could’ve figured that out myself if I’d done a bit of research on it…oh well. Thanks, Brian.

Another tip for replacing neck gaskets…
If you want to do this, I would suggest contacting George Gronseth at Kayak Academy and purchasing his tool for it. His tool is for Kokatat, of course. (The suit I just did has a larger enough neck gasket ‘base’ size that I ended up making another tool for that particular gasket/suit combo out of 1/8" ABS sheet I has lying around. Worked great.)

However, the main point here is that the instructions that come with George’s tool are much better/more comprehensive than what Kokatat puts out and may save time/money/frustration. Ooe important aspect of learning how to do this stuff yourself is that these neck and wrist tools easily fit in a repair kit and in the boat, allowing repairs during trips if need be.

You can make the jigs yourself
Kokatat provides dimensions and you can easily make them from any reasonably rigid material. I chose 3/8" plywood, as I expected to use them many times (and have done so), but I know people who’ve used corrugated cardboard with success.

If anyone needs more instructions that Kokatat has on their site, I have a “Dry Suit Repair” album on Webshots with pics of the process at:

Frankly, I can’t ever imagine carrying the jigs, the number of clamps necessary to do the job right and the other supplies necessary for replacing a neck seal with me when I paddle. A bicycle tube patch kit and some duct tape for worst-case situations are all that’s necessary.

Gronseth’s kit is quite compact…
He’s found 10 very small but very strong clamps (probably 3" long by 1 1/4" wide) that are included in the kit. The jig itself (the one I made) is essentially just a 1/4" thick disk (with split halves attached) that will slide in almost anywhere. Very little extra bulk. Nothing wrong with your approach, however.

Interesting technique there, Brian.
Obviously it works well, but is much different technique that what Gronseth uses. The technique pictured uses many more clamps because both discs seem to be individually clamped and two discs vs. one disc and split halves. Very interesting…

Disks, rings and clamps
The small disk that Kokatat recommends is probably not necessary, or at least it could be made thinner and lighter than mine. All it really does is provide some shape to the new seal and it never gets clamped. A piece of cardboard, thin plastic or similar material would do the job just fine.

It would be a pretty simple matter to split the ring, but considering that it’s an inch smaller in diameter than the large disk, there’s nothing to be gained by doing so. The two pieces of a split ring would be more difficult to handle and clamp evenly, so there are good reasons to stick with a one-piece ring.

The reason for the number of clamps is that dry suits tend to be pretty lumpy and they they don’t like to stay round, so it sometimes takes numerous clamps to hold the suit in position on the disk. Having too few would be a problem. Notice that the clamps shown holding the suit to the disk are small (3"), like the ones George uses.

Realistically, the number (16) and size (6" & 9") of the clamps pictured in the next to last photo is overkill. I have a lot of them from other projects, so I used them, but 8 would probably have been enough. However, the larger clamps provide MUCH more clamping pressure than the 3" clamps and for that reason alone, I prefer them. Considering that these are available for around a buck apiece, it’s no hardship to purchase enough to do the job right.

Very different tools and techniques–
Check out:

I included a crude description to try and communicate the technique.

Actually, it’s nearly identical

– Last Updated: Apr-30-08 1:31 PM EST –

The technique is essentially the same, except that with the method I've been using you install the neck seal on the ring before joining the suit and seal. While I haven't tried it the other way, it seems to me that the ring provides much better control of the otherwise floppy gluing flange on the neck seal.

BTW, if you cover the ring and disk with clear packing tape, it works as a very effective "release agent".

That’s a good tip re the packing tape…
Wrapping the split halves with packing taped would speed the process, especially if doing this in the field. (Using the Cotol-240 can speed the entire set time of the Aquaseal to only 2 hours, so you can concievably have a fairly quick repair while in the field.)

It’s actually quite easy to position the gasket on the disc/fabric/Aquaseal using a larger yogurt container (or something similar–I used some tupperware) positioned through the gasket opening as a handle. But you really don’t even need that if you’re careful. Aquaseal seems very forgiving if the gasket needs to be moved around a bit. Just lay it on the Aquaseal carefully, move it if necessary to position and clamp it down with the splits and wait to cure.

If you want to accelerate the process…

– Last Updated: May-01-08 1:00 PM EST –

...use OS Systems' glue instead of Aquaseal. It dries in a matter of a few minutes and you use it like contact cement. Apply to both sides (two coats), allow to dry, then join the seal to the suit. I clamp it securely for a few hours, but realistically, it would probably be safe to use almost immediately as long as you rub the new flange down good and tight. That would make field repairs more practical.

Like contact cement, the glue doesn't allow for easy repositioning (so you'll want to use the ring method to hold the new seal), but if need be, you can heat the area and it will allow the parts to move. You also use heat when you want to remove a seal attached with their glue.

The technique you’re using makes…
…sense, especially with that ‘contact cement’ like glue. Two ways to skin a cat.

After the Aquaseal has cured, I remove the split rings and disc (very carefully becasue the fabric or old gasket edge can be pulled away a bit from the new gasket if the split rings aren’t properly coated with release agent) and then put a bead of Aquaseal all the way around at this point. Just keeps this area from starting to ‘delaminate’ and protects the edge of the fabric or old gasket where your head goes through every time you use the suit.