Seacock size, Bavaria 38 Holiday (2000)

[Twhitt]

Hi, just got a 38 Holiday, and all the seacocks are seized open, so need replacing. Anybody know the correct size fitting, have heard they are 3/4 in.

Looking to replace through hull fittings and valves with potentially 'Trudesign' fittings from the SVB website.

I don't have immediate access to boat as it is currently in South of France, and I want to get parts before going back out.

Thanks

[Lyra]

At least on my B36/2004 all through-hulls and seacocks are 3/4" except holding tank outlet - 1-1/2"

[Nigel]

My boat has two sizes: ¾" and 1½" BSP. This being the bore diameter, across the threads measures about ¼" more.

[Symphony]

The Tru Design are made to BSP sizes, so 3/4" for inlets and waste water drains and 1 1/2" for toilet outlet. Suggest you replace the whole assemblies with either DZR metal ones of Tru Design. Easiest way is to grind off the outer flange of the skin fitting and push the assemblies in from the outside. Trying to dismantle them in situ is often extremely difficult.

[Twhitt]

Am thinking to use a cone drill on the through hull fittings, then replace through hull and seacocks with Trudesign fittings.

Looking at photos of current fittings, the valves are straight onto through hull fitting, but thinking of adding back plates, epoxied in between the inside hull and through hull nut for added strength?

[Lyra]

I replaced the heads throughulls and seacocks last year and added a backing plate - I used GROCO parts.
You can take a look at here - http://www.sylyra.com/seacocks_e.php

Removing the old ones was not complicated, even doing it without assiatance. I used a "throughull wrence" (or whatever you call this instrument for throughulls that has several "steps" to fit each diameter) from the outside while a wrench held the nut inside (it is a tight space so the handle was somehow jammed ad did not turn). 

[Symphony]

Am thinking to use a cone drill on the through hull fittings, then replace through hull and seacocks with Trudesign fittings.

Looking at photos of current fittings, the valves are straight onto through hull fitting, but thinking of adding back plates, epoxied in between the inside hull and through hull nut for added strength?

Yes, the cone drill will do the job.

No need for any backing plate as the hull is solid around the fittings. There is no strain on the fittings at all, so why would you want backing plates? On some boats they are needed because the hull is curved at that point, but think you will find on your boat it is flattened to provide a sound landing for the lock nut.