DRAGONFLY Trimarans User Forum

Hi,

I'm looking for some advice on structural issues we're having with a wing.

We have a DF800SW, last year we suffered damage to the outboard end of the port forward wing when we hit a wave. It was professionally repaired, but the cracking came back fairly soon after re-launching post repair.

I have all reasons to believe the damage was repaired properly. The repairer is experienced and has very good reviews.

Where the damage has occurred seems an obvious weak spot, (see photo attached) it is between the stainless bracket and the aluminium strip. Plus this is where there is a cut out for the waterstay.

So i am wondering has this happened to anyone else?

I also wonder whether this stainless bracket was ever extended by Quorning, or has been extended by anyone themselves, to overcome this weak spot? The same bracket on a local 920 does extend over the waterstay cut out, and the DF800 manual shows sketches where the stainless bracket does also overlap the waterstay cutout. Could this be a design iteration?


Any help will be greatly appreciated.
Thanks
Sam



Photos:
Our damage
https://imgur.com/Mk1LJqZ
https://imgur.com/ftE1YhE

Sketch from DF800 manual
https://imgur.com/e9m0KKN

Larger bracket on a DF920
https://imgur.com/BP1DVGl

That is a known weak point on all older DF. When the boat is heeling the ama's "turning table" is pushing towrds this weak point and it breaks down.

I suggest you to remove the stainless steel part and weld an extension there as is shown on DF920 photo.

Not a big task.

Hi Mika,

Thank you for the advice, we will likely go this way and extend the stainless bracket.

I have a local DF920 to use as inspiration, but do you know whether anyone else has made this modification to a DF800 before? To avoid us re-inventing the wheel?

Many thanks
Sam

Mika Harju wrote:That is a known weak point on all older DF. When the boat is heeling the ama's "turning table" is pushing towrds this weak point and it breaks down.

I suggest you to remove the stainless steel part and weld an extension there as is shown on DF920 photo.

Not a big task.

Hi Mika
Could you make such an extended/reinforced stainless steel part for DF800 SW ?
Best regards Thomas