Wednesday, January 30, 2008

Cheek block assembly for the daggerboard case

Long days at work and a flu bug have slowed me down somewhat. I was all prepared for the port side daggerboard case lamination and bagging but found that I was short on peel ply and epoxy resin. So another visit to Noah's, which is literally a 5 minute drive from my workplace.

I had started using MAS epoxy resin on the outer float laminations because it has excellent moisture resistance and it was on sale. I've been getting good results so I'm still using it on the daggerboard and case. I also picked up some graphite powder for coating the inner case surfaces.

I also have the first bits of real hardware for my Raven. The cheek block and the anodized Al 6061 T6 mounting plate.


Anonymous said...

On the cheek block for the daggerboard - that design has been problematic for previous F-Boats. What happens is that the screws or the screw holes corrode and leaks develop. It might be worth replacing the fancy anodized mounting plate with G-10.

David Paule

GK said...

Really, ... even though my boat will be fresh water sailed, I find that really interesting. Ian Farrier does suggest the SS fasteners and the Al should be isolated with sealant and nylon washers but G10 does sound reasonable if it has the required strength properties.
Thanks David, I will consider.

Fram said...

For this reason I made the whole assembly from SS316. (a little heavier than Alu)

GK said...

Thats actually a good idea too, then there is no possibility of galvanic corrosion with the dissimilar metal types. Must be a fraction of a pound heavier - easy to calculate. If I remember correctly Al is about 1/3rd the density of steel.

It is interesting that with all the changes to the F-22 (to reduce metal) this assembly was not touched. This tells me that he thinks it is not possible.