What do you all think of "Flex Seal"

[tjandoverguy]

ihave a 98 hunter it leaked around almost flat window cleaned and used silicone one coat stopped leak i have coated all intrusions

[atlroofman]

Originally Posted by Rohan

If you haven't seen the ads, Flex seal is basically a group of products that claim to provide a flexible, water tight seal, applicable with a spray can, tape, or caulk type gun. https://www.flexsealproducts.com/

I have seen a lot of these commercials, including where this guy makes a functioning boat out of the product, but normally I don't pay that much attention to TV.

There are many other sealants on the market. But the commercial claims it even hardens UNDER WATER, and that got my attention. That is a big deal, and something that I could have really used in the past. (previously, the only product I knew of that would fix a leak underwater was this stuff for swimming pools and it was actually two different types of paste that you had to mix together just prior to applying). So using Flex Tape, for example, you could theoretically patch a small leak on your boat, or use the Flex glue or Flex Shot to repair through hull seals, even if they are underwater.

So I bought some flex glue. At the moment, I don't really have anything critical to use it on so I made a small test, deliberately as difficult as possible. I filled a bucket with cold water. Then put two pieces of very smooth plastic under the water and glued them together. I really didn't think this would work, but I felt a grip on it right away. The product says it takes 24-48 hours to fully cure (underwater might be different, I don't know). But about 12 hours later I checked it, and they were holding together pretty strongly. That's amazing!! I have never seen anything do that before.

On the other hand, not all reviews are positive. The most common complaint on web sites seem to be that the stuff requires a special type of caulk gun and is sometimes too difficult to push out of the tube (apparently it has a shelf life of 24 months and older product apparently is very thick and more difficult to apply than when it is fresh)

Have any of you tried this? What do you all think of its potential?

Opened my commercial roofing co in 1987, I have used litterly everything that stops water. The family of products they are reffuring to are elastomerics.
Only use solvent base elastomerics ! never any water based.
Things we use that stick and hold through water are Geocell in a tube or can (thick liquid) , Eternal Bond reinforced tape, And for out of the water uses always use the Eternal Bond primer. You can use closed cell fabric with the Geocell liquid to give it tinseil strength enough to bridge voids. They are all available at your local commercial roofing supply wherehouse and can be sold to the public.

[dduresky]

My hypalon dinghy had a 2 inch tear. after 3 unsuccessful repair attempts costing about$150 i was about to give up. Tried Flex Seal. Two years later... no leaks. YMMV but I love the stuff

[sanibel sailor]

Originally Posted by billdre

So I have one specific use for the Flex Seal spray that has worked well.
At the aft end of my encapsulated keel where it curves into the hull there was a small crack which dripped water after the boat was hauled in the fall. I had it examined and the fiberglass guy says it was an easy fix. He grinds it back to solid underlay and rebuilds the curve. Next fall it's cracked again and dripping until Spring.
This crack doesn't reach the interior of the hull. No leaks inside at all. So I conclude that the issue is the boat gets fixed when it resting on the keel then when they lift it to launch me it opens up again. So the part that attacked me to "Flex Seal" is the flex part. Five years ago I removed all the bottom paint from the area, sanded it and followed the instructions on the can. Several layers over time. Next Spring no leak. It lasted two years then I did it again. Worked again. Next summer it will probably be due.
It's obviously a very specific minor problem. But it keeps the sea water from getting up into the underlying fiberglass or whatever else might be affected. So I like it.

does it keep water out or keep it in?

I used a quart of the white liquid stuff to paint some black foam rubber mats used as cockpit cushions so they will be cool enough to sit on. Seems OK with very limited use so far.

[Clamdigger]

Originally Posted by Minggat

I bought a roll of the tape. Last week I tried to get some off the roll. Good thing I didn’t NEED it

I gave up. More important things to do. But now I know that I should expect a problem.

Yeah, the tape rolls have a clear 'liner' that pulls away from the adhesive side as one tries to 'unroll it' Which means the companies that sell it figure anyone using their product will have 3 hands

[Clamdigger]

Originally Posted by jmschmidt

One product which features a large animal in it commercials is junk. The glue, once open, turns hard within a couple of weeks or so and the tape fails as soon as any appreciable amount of water comes in contact with it.

Don't be shy here, if it's a 'Gorilla Glue' product, then mention the name! You are giving your opinion as a paying customer. Nothing wrong with pointing out a products defects, some companies actually respond to consumer comments.

[CaptTom]

Originally Posted by dduresky

My hypalon dinghy had a 2 inch tear. after 3 unsuccessful repair attempts costing about$150 i was about to give up. Tried Flex Seal. Two years later... no leaks. YMMV but I love the stuff

Very interesting! Did you apply a patch using Flex Seal as the adhesive, instead of the expensive 2-part stuff? Seems like a good option for emergency repairs when the "correct" adhesive isn't available. Especially if it works better than that stuff and costs less.

I'm wondering if a light coating along the seams might finally kill that very slow leak I have from my dinghy's starboard tube. Mine is PVC, so not sure if it'll work the same though.

[MV Wanderlust]

My aluminum wet/dry vacuum canister developed a small leak. It gets repeated exposure to fresh and salt water. I used a can of the spray Flex Seal to coat the inside of the canister and have had no leaks in a year and a half. A buddy here in the marina insists he used some of the 4" tape to seal a small leak in a coolant hose while underway on a trip. It sealed it so well that he has yet to get around to replacing the hose and that was almost four years ago. I've seen the hose and the tape wrap but I can't attest to the length of time it has been there.

[billdre]

Originally Posted by sanibel sailor

does it keep water out or keep it in?

I used a quart of the white liquid stuff to paint some black foam rubber mats used as cockpit cushions so they will be cool enough to sit on. Seems OK with very limited use so far.

No water to keep in. It's dry by the time I apply the Flex Seal in the Spring before launch.

[dduresky]

Originally Posted by CaptTom

Very interesting! Did you apply a patch using Flex Seal as the adhesive, instead of the expensive 2-part stuff? Seems like a good option for emergency repairs when the "correct" adhesive isn't available. Especially if it works better than that stuff and costs less.

I'm wondering if a light coating along the seams might finally kill that very slow leak I have from my dinghy's starboard tube. Mine is PVC, so not sure if it'll work the same though.

I brushed it on over one of the 2 part patches. It was a last ditch effort and not very pretty but hell... 2 years old and holding

[BVLew]

I used the tape to fix a tear in a Porta-bote. Worked fine for the few months while I still had the dinghy. Haven't heard back from the guy I sold it to (was switching to a hard dinghy anyway).

[Chotu]

I have tried it in part of my construction of windows on my bridge deck. As an extra barrier to leakage.

It’s been baking in Florida sun and getting rained on almost daily.

Looking forward to seeing how it held up in a few months when I return

[witzgall]

For underwater repairs, West System Six10 cures under water.

Chris

[taxwizz]

Originally Posted by Minggat

I bought a roll of the tape. Last week I tried to get some off the roll. Good thing I didn’t NEED it

I gave up. More important things to do. But now I know that I should expect a problem.

But...You have proved that it sticks to itself pretty well.

[raclapp]

Used it repeatedly as tape and as spray paint. Works great on kids old canoe. Fiberglass + gelcoat weren't issues. Kids beat the heck out of that canoe. Used tape on floor, worked great for sealing some cracks and for a light anti skid over bottom of ribs.