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Seam Sealing Tape
The leading cause of death of rain gear is loose seam tape. 25 years ago I bought a 3-layer Goretex jacket and pants with bad tape and good fabric. I glued the tape down with contact cement and it stayed through 20 years of occasional use. But it was a laborious process. More recently I bought a second hand spray skirt (it came with a sea kayak) with bad seam.
I tried gluing the tape back down again. It worked, but was laborious. I tried Seamgrip from the outside; it worked, but doesn't look great. It tried several highly regarded SA tapes, even using tape primer. A waste of time. But iron-on seam tapes work great. Use a name brand.
The shoulder/back seam is iron-on, the armpit and side is glued.
I never really looked into it, because West Systems says it's useless. I'm only part way into this, and I feel like West Systems is about 70% right.
- Penetrating epoxies are 3-5 times weaker than conventional Epoxies. Weaker than Gorilla Glue and about the same as varnish.
- Penetrating epoxies are really slow to cure, like days. And they must be fully cured before over coating (they are not compatible green even within the same brand).
- Does not help the bond. Would you bond to varnish? I didn't think so.
- Not at all water tolerant, perhaps less than other epoxies. So much for rotten cores, which are surely damp.
- Adding acetone actually reduces effective penetration. When the acetone dries it pulls some of the epoxy back to the surface with it. The epoxy does not penetrate with the acetone. The acetone does not improve water tolerance. Don't add acetone ... ever.
On the other hand, there many be some uses.
- Varnish undercoat. But I have no evidence that it sticks better than or is more durable then thinned varnish.
- Sealing questionable edges after a hatch replacement. Bear in mind that it will delay the project another several days.
- Use slow cure epoxy instead. It will penetrate nearly as well, since it has time, and will be full strength, and will be compatible green within the same system.
But I'll know more in a few months. I'm going to be leaving samples to weather.