Weird Leak in kayak - Causes? Suggestion how to fix?

Tested my kayak  (Perception Pescador Pilot 12) for leaks with air inside and spray dish soap on the outside of yak to find bubbles... Two HUGE areas.

Any idea what caused this? Kinda looks like a manufacturing defect???  (But, the yak is at least a few years old and I bought it used.)

And, most important: What is the best way to fill those ... Spread a layer of epoxy over them?  What is the best marine epoxy for this?   How to get it way down those  [rod holder???] holes?

  Your best bet to fix that is to cap the entire hole.   

That doesn't look good. I'd be concerned about other thin spots in more critical locations in the hull.

Put some bright azz led lights inside in a darkish garage if at night and look at the plastic fir thin spots, they should be easy to see.

Put some bright azz led lights inside in a darkish garage if at night and look at the plastic fir thin spots, they should be easy to see.

+1 of course you might not like what you find.

On sealing, the best thing I've found to stick to polyethylene is a product called lexel. 

On sealing, the best thing I've found to stick to polyethylene is a product called lexel.

I had never heard of Lexel, just looked it up. Polyethylene is listed under this: "Lexel sticks to nearly everything and works on almost every project, but there are a few cautions you should take to ensure your seal." Their website does not say what needs to be done to get it to stick to HDPE, but it looks like Lexel is the way to go if it will stick. See the bottom of the page here:

https://www.sashco.com/products/lexel/

No suggestions about how to fix it, just that you take it very seriously

There were other factors I wont go into here but I brought a guy in whose yak is on the bottom of the Pacific somewhere along the Marin coast

Was a real eye opener watching it tilt upright and slide down into the deep green

He had had a leak at a scupper which had been fixed by a reputable shop, but apparently didn’t hold

Took around two hours to get him a short way to Muir

Hey everyone.. LOTS of good input. At least I'm thoroughly testing the thing. Filled the drain hole with a small tube to an air compressor regulating about 5 PSI  (very low... Spraying the hull entirely with soapy water to find EVERY leak.  Also looking for weaknesses. THANKS So far only those two plus a pop rivet.

SO very surprised no one has mentioned

"3M Marine Adhesive Sealant Fast Cure 5200 (06535) Permanent Bonding and Sealing for Boats and RVs Above and Below the Waterline Waterproof Repair, White)"

I kinda thought this or its sibling, 5200 (06500) were the gold standard?

From a 7 yr old answer on a Q&A forum. Not mine.

""#407-29-2015, 04:28 PM
So I shot an email to 3M regarding 5200 and HDPE. To my amazement someone actually called me. He recommended 3M 4693H for bonding HDPE to fiberglass or metal. Said it was water resistant and would seal like 5200 but is formulated to adhere to slippery plastics like polypropylene and polyethylene. Just thought I would pass that along.""

http://www.bbcboards.net/showthread.php?t=630129

West System 655-K Plastic Boat Repair Kit
I have used it for several projects.

Here is what sold me on it - they take a kayak, saw it two pieces, glue it back together and do crazy stunts in the kayak

I’ve used g-flex and another product called gator patch.   I also plastic weld kayaks.   The photos of damage on this kayak are perfect for g-flex or gator patch.   Not a good spot to plastic weld/use heat.   There is another hobo repair called an Idaho Patch.   You use construction window weatherstrip with the tacky tar base and aluminum shinny side and put it over holes heat with heat gun then layer it with gorilla tape and heat the gorilla tape to where it’s starts to crinkle.   Good to go.

West System 655-K Plastic Boat Repair Kit
I have used it for several projects.

Here is what sold me on it - they take a kayak, saw it two pieces, glue it back together and do crazy stunts in the kayak

That's pretty impressive. Next time I have a repair I'll remember G flex.

I've used G flex a few times. It's good stuff, and the propane torch/heat treating technique makes a difference. Having said that, my experience was that in a spot that flexes, even just a little, it'll eventually let loose. I think the reality is that nothing is going to permanently bond to polyethylene.