Cutting down to the hull to install the backing plate for the sink sea cock on a CD25.

[brooksey4018]

The time has come to replace the gate valve seacocks with new Groco ball valve seacocks on my 1977 CD25! The sink seacock (pictured) is directly below the sink n the Portside under the salon bench. The current recess in the plastic skin is too small to take the Groco backing plate for the appropriate size greco seacock and the plastic skin is not a good surface to take the sealant.

Has anyone else tackled this job and if so, how have you overcome this problem?

I am thinking of cutting through the skin to be able to bond the backing plate directly to the hull. I am guessing the skin is not bonded to the hull and there is a small gap to allow me to cut the skin without cutting into the interior surface of the hull. Does anyone know what the construction of the interior skins were for these boats.

Any insight would be appreciated.

Thanks

[brooksey4018]

I ended of cutting a larger recess out. If anyone else is thinking of doing this at any point it's solid glass/resin under there. I did it with a Dremel, it was a bit tricky but did the job.

[Carl Thunberg]

Thanks for the follow-up. My former CD25 looked nothing like what your photo showed. Something must have changed between 1974 and 1977.

[brooksey4018]

Yes, I am learning that there are a lot of small differences between the years of manufacture.

Here is the Job finished.