How Long does Flex Tape Last?

If you’re familiar with the powerful adhesive tape known for its ability to seal leaking pipes, damaged roofs, and even boats sawed in half – then you might be wondering “how long does flex tape last?”

I previously put some of flex tape’s claims to the test using several real-life applications and was pleasantly surprised with the results. While the adhesive tape performed well in most of these tests – including during underwater use – it didn’t provide an answer as to how long flex tape lasts.

The manufacturer markets the product as a temporary fix for emergency repairs and states that it’s not meant to be a permanent fix. That said, I figured knowing how long flex tape lasts would be useful information for anyone planning to use it for repairs.

So, how long are we talking?

Flex tape works wonders when you need a quick fix around the house. Unlike duct tape or gorilla tape, Flex tape is specifically designed to be used in wet environments.

Due to its ability to seal and contain leaking water, there are all sorts of applications you could use it for including temporality patching leaking plumbing, sealing leaky pool inflatables, covering up cracks in outdoor lighting, and much more.

The limiting factor for flex seal seems to be its ability to withstand moisture for a prolonged period of time. In my previous testing, the only time I ran into leaks was while patching a PVC pipe from the exterior.

For this test, I figured the best method would be to repair a leak with flex tape and then see how long it held up.

Looking at some of the other flex tape tests online, it became clear that in many cases the tape was able to mostly repair a leak, but sometimes a trickle of water would manage to work its way through. That’s still quite impressive and would still make flex tape useful for emergency repairs, but less so for long-term repairs.

Bucket Test

The first test involved drilling a 1 ¾” sized in a bucket with a hole saw. I then applied flex tape to both sides of the hole, patching it from both the inside and outside.

Next, I filled the bucket up with water. No leaks formed right away, so I left the bucket alone and checked on it periodically over the next 24 hours.

testing flex tape with bucket

No leaks formed whatsoever, which as far as I’m concerned is a complete success. As the tape isn’t catered towards long-term repairs around water, this is more than adequate as a short-term repair.

PVC Test

Next up, I tested Flex Tape on a piece of 2 inch PVC pipe. I drilled several holes near the end of the pipe, applied flex tape to both sides of the pipe, and then filled it up with water.

drill and pvc pipe

The repair seemed to stop any water from leaking initially, so I left the pipe alone in a bowl and checked on it every once in a while.

The repair held back the water for the most part, but there was a small trickle that formed after some time. After 24 hours the pipe leaked a few tablespoons worth of water.

I’d still consider this a moderately successful test, as the repair mostly stopped the water from flowing, and performed much better than most other products I’m aware of.

Underwater Test

Lastly, I tested the incredible claim that flex tape can be used underwater. To do this I cut another hole in a 5-gallon bucket and carefully filled it with water while covering the hole with a thick piece of plastic.

Then I took my piece of flex tape and got it ready to deploy underwater. I released the piece of plastic holding back the water, let the water flow freely, and then promptly sealed the hole using the flex tape.

flex tape underwater bucket repair

To my surprise, the flex tape not only sealed the leak, but also appeared to do so without any trickles or drops forming. Like the previous tests, I left the bucket alone and checked on it over the next 24 hours.

The repair held up completely, with no leaks forming over this period. I was pretty stunned by this result, as I had expected at least a little bit of leaking to develop over time.

Denis Gardner

I've loved tinkering and fixing things for as long as I can remember. So, naturally, I gravitated towards DIY and home improvement when I bought my first home. Nowadays you can find me writing about my passions or messing around with my newest tool!

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