Has anyone used Flex Seal tape for a quick fix on your yak?
I carry duct tape and a small repair kit but was thinking to add Flex Seal tape to my repair kit.
I don’t kayak in fresh water so I’m hoping to find anyone that kayaks in salt water for their results good and bad.
Freya Hoffmeister uses it. Can’t get a better endorsement than that. Her February 17, 2019, report mentioned her partner scraping off the Flex tape to make a more permanent repair. http://freyahoffmeister.com/north-america/na-sec-1-north/sun-17-02-2019-day-326/
Sounds like good stuff, though I haven’t used it.
duct tape endorsement:
I’m very lazy about doing ‘proper’ repairs on my boats.
I’ve had a ‘duct tape’ repair on a Tahe Greenland T (below water line) holding for the past 5 years.
For trips, I’ll also carry a tape that can be applied when the surface is wet (eg, while underway (note: I’ve had sharks try to make that a necessity))
I forget what it’s called, google will find ‘underwater tape’.
@Mike.S - what is your kayak made of? Much different stickiness results are had with composite versus rotomolded kayaks
Many decades ago we gouged the bow keel of an ancient canoe badly on a rock in the middle of a 4 day paddle camping trip. It was an old wooden canoe that had been fiberglassed over where the canvas had once been. A big enough chunk was knocked out that we had to either stop and patch or dedicate one paddler to constantly bailing. Going through our sparse kit after we hauled ashore what we came up with to patch was chewing gum (Juicy Fruit, if I recall correctly) and a package of that peel and stick RipStop adhesive tape for plugging tears in your down sleeping bag. We chewed up big gobs of the gum and stuffed it into the yawning gap then laid two layers of the International Orange ripstop patch over it. We were thrilled to discover that the patch not only held but lasted through two more days, even of dragging over gravel bars. Anyone who has ever swigged a cold drink with a wad of chewing gum in their mouth knows that the stuff turns to a sort of stiff epoxy once it chills. We figured our jury-rigged patch could be peeled off once we got home and could execute a “proper” repair. Three years later we were still paddling that forest green canoe with the big orange nylon patch on it. In fact. I think its owner sold it to the next guy that way!
We carry a roll of flex tape in the kayak for the last two or three years. It’s worked “good” we haven’t had any leaks. 
I’ve got a roll of FlexTape that I carried in my Fathom. I wonder if it could be used as a keel guard on the composite kayak. Also thought about using helicopter tape for the same purpose. It comes off easier.
Helicopter tape is designed specifically to be resistant to sand and other lightweight debris that can be kicked up by the rotors. We tried it on a kayak and found that rocks, barnacles, oyster shells and such shredded it in pretty short order. Getting it off was not easy, as the adhesive is very aggressive and the residue is difficult to remove. I would never repeat this experiment!
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I have used flex seal on my roof. And a I have a roll one of its competitors sitting in my hallway for spring, when I can safely get up there and see what damage last month’s ice dam may have left behind. But if it works that well to seal, it also means that you have the devil of a time getting it off again and there will be some residue.
If it were one of my ancient plastic WW boats for banging around shallow rocky creeks in spring I would consider using it. But I think not on a composite boat unless I had no choice.
I checked on the customer reviews of Flex Tape and found more complaints about it not holding up to immersion or abrasion than I did praise for its performance in such conditions. Somebody on the inflatable and folding kayaks forums had asked about it and I was curious. I know for a fact it doesn’t adhere well to vinyl – the solvents for vinyl (which would be needed for an affective bond) are too volatile to survive as a tape adhesive.
There are rubberized strips that we folder fans use to patch or reinforce wear areas on our hulls that are applied with solvent glue. I suspect that would hold up better than Flex Tape, even on a poly kayak. If you’ve got a composite, use a patch with the same solvent adhesives as would have been used in the original material if it is fiberglass. If you’ve got a kevlar boat you probably are out of luck. I used to dissolve Kevlar fibers for solutions when I was a polymer chemistry lab tech and its solvent is fuming (130%) sulphuric acid…
The problem with polyethylene kayaks is getting anything to bond to them firmly. My understanding is that this is because they are chemically “low energy” plastics (you would probably know more about this than I do). Passing a flame over the surface apparently helps, but I recall that it depends on whether it’s it’s cross-linked polyethylene or not.
Fiberglass, Kevlar and carbon fiber composite kayaks don’t use solvent adhesives, they use two-part resin systems (polyester, vinylester or epoxy). The only difficulty with repairing Kevlar is that you can’t sand it to shape, as it becomes fuzzy. A sharp scraper eliminates that problem.
One thing that I’ve seen used as a universal patch is the “ice shield” material made for roofing. It apparently bonds to just about anything. I have a patch of it that I carry just in case.
I have some of the roofing tape which you may be referring to (Eternabond), which is a pretty amazing product – I used it to seal seams on a 1977 motorhome that I restored. It has an advantage over just about every other adhesive in that it can be applied underwater and still bond. The main drawback to it is that the thick layer of polymer “glue” on it sticks to EVERYTHING and the edges of the roll of tape want to adhere to anything that the roll is contained within. I peeled and cut some short pieces off the roll I have and folded them into waxed paper to put in my patch kit. I should get it out and see if it will release from the waxed paper. That’s some way sticky stuff. I had trouble getting it stuck to my skin when I was doing the RV project. And it is impossible to peel off if you lay it down wrong.
All true! That’s why it works.
I used flex seal tape to secure the internal wiring and steering tubing and it works almost too good. Trying to take it off when I made a mistake was tough. Only time will tell if it lasts through several seasons but from the looks and feel of it, it seems it will stay stuck for a looong time.
Since this thread was posted, I’ve used Flex tape on a gutter install this spring. When I removed the gutter last month (to keep it from filling with ice and snow), the Flex tape wasn’t difficult to remove but did leave a bit of a residue. Maybe because it was cold.
A couple weeks ago the county snowplow blade split my mailbox post in half and ripped the door off my mailbox. Snowplow driver returned with apologies, wood sections, screws and a drill and got the post reattached. Flex tape repaired the mailbox door. It looks a bit beat up, but has character.
The tape does work when you need it.