voyager35
Well-Known Member
I am currently in the middle of renovating a Kelly 42 cat . I found the mast step was very wet inside and was starting to show some signs of compression so i cut the top skin of expecting to find the step was constructed out of layers of marine ply. The total thickness of the step is 75mm.
What i found was the bottom layer was a single sheet of 15 mm ply but the other three layers were in 50 mm wide strips encased in a high density filler that had a 10-15 mm wide vertical fillet going the full depth between each of the ply strips. There was also a fairly thick layer 5-7 mm deep of filler between each layer of ply.
My initial reaction was that the yard that built the boat had used ply scraps to build up the mast step, but when i thought about it began to wounder if it had been constructed this way to stop the ply compressing as the mast step must be under huge compression and as it spans the top of the centre board casing is only supported in a small area.
Your thoughts /knowledge on this would be appreciated
What i found was the bottom layer was a single sheet of 15 mm ply but the other three layers were in 50 mm wide strips encased in a high density filler that had a 10-15 mm wide vertical fillet going the full depth between each of the ply strips. There was also a fairly thick layer 5-7 mm deep of filler between each layer of ply.
My initial reaction was that the yard that built the boat had used ply scraps to build up the mast step, but when i thought about it began to wounder if it had been constructed this way to stop the ply compressing as the mast step must be under huge compression and as it spans the top of the centre board casing is only supported in a small area.
Your thoughts /knowledge on this would be appreciated