I've recently bought myself a Dagger Mamba and found that it was leaking like I've forgotten to put my sprayskirt on.... After taking the boat apart I was puzzled to find what I believe is a design flaw from Dagger.

In stead of writing the entire story here, take a look at my blog entry (students club in Norway): OSI Elvepadling Blogspot

Have anyone else experienced this on their Dagger boats? Hope it's not just me thinking adding two threaded parts on one screw is clearly not a good thing.

I wouldn't call it a flaw so much a a choice. There are other manufacturers who mount their seat the same way and they run into the same problem. It's because the seat moves a little bit from side to side. The best solution is to use minicel foam and support the sides of the kayak seat so that it does not move as much. That will slow the process down. You have also come up with a good fix.

Other boat makers mount their seats from the side, but I would still recommend using foam to fill any spaces between the seat and the side of teh boat. The screws might not be in danger of pulling through the boat, but ALL seats move a little bit. Stopping your seat from moving will help reduce stress on all mounting hardware.

Good point - I'll pad the seat at the same time!

One thing though; the boat was brand new and I guess the folks mounting it does not jump around inside the boat. Also, when comparing both sides the threaded washer on the damaged side was actually curved after the hull - the other was still flat.

the problem with making things out of plastic is that each boat comes out slightly different, and each seat is ever so slightly different (less with thermoformed seats). So not everything matches perfectly. Probably the reason you discovered one bolt that was bent.

The mounting points are high stress points and something will eventually bend. Working for DragoRossi I know that the decision to mount the seats from the side and on rails is (partly) because the rail will flex but it won't matter as much as if a screw were to flex. Still have to put foam on the side of the seat though. (just a different solution, time will tell if it's better)

As far as the top-mounted seats, I have seen a few people take them out in a new boat, and put a large plastic washer under the head of the bolt to make a reenforcement area so that it's stronger. It's a bit like your idea on your blog, just easier to do when the boat is new.

I read your article. Interesting. Just by looking at this picture:



There is a small black washer (rubber) underneath the washer that sits under the head of the set screw. It looks to me that the bolt was over tightened. Perhaps, and I repeat, perhaps when Dagger assembles their boats they would use pneumatic or electric screw drivers etc to speed up their assembly line. (like most assembly lines in other industries) It is possible that whoever tightened this screw way over tightened it. With a pneumatic driver it is pretty easy to do that and given a fast rotation of the screw itself and the washer, it would have heated up during that process and hence and black residue still evident and also the recess which it has created from heat (maybe just a tiny bit) and of course the mechanical damage created from them over tightening it.

Of course this is only speculation on my behalf.

(As a side note I should add that Wave Sport and Dagger are made by the same company (Confluence) and I had 2 Big EZ's crack in that exact position. My situation was different and it cracked due to another reason. The reason being that once you sit in the boat, the distance between the bottom of the seat and the mounting plate was LESS than the distance from the bottom (inside) of the hull to the mounting position. This caused the seat to effectively HANG off of the actual hull of the kayak and therefore induce a major stress concentration on that area. First boat cracked after about 8 months and the second under 3 months. Both times the boats were replaced, free of charge, no hassles.)

I can only guess that it was an assembly error and they should replace it. Or repair it but not as good a option. Let me know what happens. I'm surprised they have ignored you this far. Maybe mail them this link and yours too as bad press for any manufacturer will make them think twice before shaking you off.

Just my thoughts from working in manufacturing environments and seeing similar things happen.

Good luck