Help - Mirage Adventure Leak Repair

Yes, that’s the dreaded drivewell crack, though it doesn’t seem to have extended down past the ledge. I had two AI’s, a 2008 and 2010, replaced under warranty because of it. Hobie fixed it in the 2011+ models. The large amount of water you are getting in is probably due to it flexing and opening up when you power down on the Miragedrive.
I think the flexing is what makes it so hard to repair as anything you weld/epoxy is likely to crack.
That’s why I suggested the VHB. It remains flexible, though on that ledge there may not be enough surface area for it to stick.
Another way of leak testing is to use an airbed inflator when the hull is on the water. You can put the hose into the bung hole, seal anround it with an rag and pressurise the hull. Any leaks will show as bubbles. That was the method I used to discover a cracked rear scupper tube.
Maybe try the welding/epoxy and then add a layer of VHB over it all both internally and externally?

Do you think there is any way to get a plastic welder in there?

I had an accident (hit a navigation buoy) a while back where I ripped the ball holding the aka brace out of my hull, bought a cheap PE welder iron from Amazon, it came with PE filler and so I just welded the fitting back in, it might be possible to close the crack with a similar welder.

https://www.amazon.com/dp/B0C9JK7W7M?re ... tails&th=1

I would definitely try a weld on that after drilling small holes at the crack ends.

One problem people have with welds is poor adhesion where the plastic material flows onto cooler material and does not bond well. I have had this happen. Now I heat the area with a heat gun right before each individual weld and have much better success.

Peter

If the crack is where I think it is, ( under where the front of the mirage drive sits). That is a high stress area, and even on a new keyak if you put the kayak in a pool, have someone start pedaling with the nose of the kayak up against the edge of the pool. Then stick your hand under that area as they are pedeling, you can actually feel how much that area flexes. Even on the newer hulls with the brass insert inside.
Typically no amount of welding can stand up to that force. One of our hulls got so bad, that we made a little V bracket from aluminum that spread that force over a wider area. We just bent up some aluminum stock so the front of the mirage tang sat on that, then the aluminum followed up the wall, ( on the inside of the mirage pocket), then two long flat areas that we screwed to the floor in the kayak. We then tested in the pool again, and the hull flexing went away.
We were then able to weld the crack with the hobie welder. Because we solved the stress issue, the weld held up just fine, ( didn’t get any worse, ( as they normally do). We also did the silicone trick on the inside, as I outlined earlier.
It never leaked again after that.
We attacked the root cause of the problem, not the resultant problem, ( that’s important).
Just welding it is like putting lipstick on a pig, ( doesn’t solve the root cause), which was a bad design to begin with.
Hope this helps
FE

Edit:
We did very long distance offshore kayaking with our many Tandem Island kayaks, and had our mirage drives upgraded with Eclipse fins, ( require double the pedaling force). That was the only way we could get the hulls to survive offshore, in sometimes pretty harsh conditions in open ocean. Our TI’s were heavily modified for offshore use.
Just to be clear.