Builders' Forum Archives
Re: Filleting joints....
Posted by LeeG on Dec 15, 2007
I guess what I'm trying to say is that the glass on the interior and exterior can be the structural element and not a huge fillet. Once you apply glass it's the same as putting on a wet-out coat through glass onto dry Okoume. It's a stong bond.
IIRC the Arctic Hawk uses fillet for the structural element in the cockpit but for interior joints that are being glased you don't need fillets as wide as shown in this drawing.
The difference between a 3/4" wide fillet and a 2" wide fillet over 50' of joints is a LOT of goop, probably a pound. I did some back yard destructive testing with little fillets and glass, big fillets and no glass, little fillets and tape, etc. Without pre-wetting the wood the failures were all in the wood or junctures where glass ended next to bare wood. Where there were failures between fillet and wood the wood was all coming apart anyway with the adjacent veneer and intermediary ply lamination coming apart.
In other words for it to be an issue it would be in a catastrophic event where the kayak is crushed to pieces and the pieces would look a bit different between wetted and pre-wetted but not much. Which is more damage than what folks have experienced when the empty kayak flew off the roof rack at 60mph.
A tangent to give an example of how the issue is moot. One of the original demo Chesapeakes, the WR164 or double I forget which. Thick fillet in the stern, lots of goop. When the exterior was glassed the stern was sharp and the glass was thin with no more than one slightly sanded layer of 6oz covered in paint.
It fell to the floor 18" off the middle kayak rack onto the stern and cracked along the stern for about 8". The failure was on the outside and between the laminations, not the fillet/wood joint on the interior.
In Response to: Re: Filleting joints.... by LeeG on Dec 15, 2007