how to fix a leaking problem

Hi folks, yes I know that the leaking problem has been treated in other posts. I read most of them but I preferred to open a new post thinking that maybe there could be new products in the market to repair the hull of our boats.

I have a very small hole in the hull, Since it is under the water line I get many many many gallons of water. The position of the hole, from what i read, is very common, it's were the mirage drive seats and maybe Hobie should do something to reinforce that small but delicate point.
It was invisible and I didnt noticed it when i was looking for it. i found it only filling the hull with water.

my qyestion for you is: how should you fix it? I know there is the (expensive) welding kit.
Considering its position and microscopic size maybe there are seals or products that could be used. any suggestion is welcomed
Giorgio

this is the link with the photo

https://drive.google.com/open?id=17cM5_f4d_uJdM-RXkFjCRIyV8Y5F-V79

If I'm understanding where the crack is, it's caused by flex-fatigue from pedaling. It looks microscopic but like flexes open when you pedal. I've heard mixed reports on fixing this crack. I don't have personal experience, but your likely best chance at a real fix would be to drill the end of the crack to reduce the stress concentration, cut the crack open a bit, use the welder to slowly fill it all in being sure to blend the new plastic with the old, and reinforce the area with embedded stainless steel mesh. Good luck!

Let us know how you make out.

Hi. thanx for the suggestion.
I talked with my dealer and he suggested me for such a small hole i could also use a glue named Stormsure
I will also order the welder plastic from hobie
i dont know if enlarging the hole drilling it could help. i should be afraid to increase the damage

Before you start any repair, is the boat still under warranty? If it's under 2 years old, Hobie should replace the hull no questions asked. If it under 5 or 6 years, they may be willing to work with you on a prorated replaced. That should be your first course of action. If your dealer won't investigate this for you, work with Hobie directly.

You say it's a microscopic crack, but you are getting gallons of water in. It looks small when just sitting there, but it's probably flexing open when you pedal and getting bigger with every stroke. You can try Stormsure, but know that there are very very few adhesives, glues or epoxies that will stick to the polyethylene the boat is made out of and I almost 100% certain that's not one of them. If you had a hole you needed to plug in a static area, it might work fine, but for a crack, I'd say you have less then a 1% chance of a permanent or even semi-permanent fix. It won't hurt to try, but keep your expectations low.

If you want to use glue, you need to find something specifically formulated for polyethylene. Something like this https://youtu.be/h-9yhanz5DE

As far as drilling a hole, do some research on crack drill stop you can start here : https://www.reddit.com/r/engineering/comments/6bdugb/how_does_stop_drilling_arrest_metal_crack/

Certainly don't go drilling holes and try to patch with Stormsure! You'll definitely want to be in a position to fill it in with welded plastic or a specially formulated product.

Good luck.

Hi.
my tandem was built in 2014 therefore it's out of warranty, moreover I bought it in another country (Switzerland) and probably should be difficult also to involve a dealer. I understand what you mean with drilling the crack in order to avoid that it keeps on "running" but maybe this apply only to the "linear" crack that is not my case. my "hole" is like a "spot" and was probably caused by a friend of mine who didnt use the mirage drive properly.
the reason why i got so much water is that, though small, it's under the waterline and i was many hours in the water
I agree that the first attempt with the glue could be unsuccesful and in fact i plan to go for stronger solutions. i exluded using the 3m 8010 because it's expansive since u have to buy also the accessories for it.
i ordered some sticks of red plastic from hobie that i will weld and i have also a friend who can put some fiberglass on that part.
honestly i am afraid of heating the plastic of the hull with the welder. what do you think about it?

Provided your plastic welding technique is good and proper, it is the best overall solution. The end result is not a filled crack, but a reflowing of plastic so that everything is a single unit, again. No crack. No fill. Just solid plastic.