Thru-Hull Fittings

[Charlie]

I have researched a little bit and found that there isn't really a European standard for the thread on a thru-hull fitting. My new to me boat is a 2006. Some of the seacocks are frozen and I need to replace them. I am trying to decide whether to replace the skin fittings or not. What I am thinking of doing is sanding off any paint on the mushroom heads and inspecting to make sure that they are bronze and not brass. Any discoloration will lead me to replace all of them. Even the 3" monster that is used to empty the holding tank. This will be quite expensive so I want to make sure I do it right. A method that appeals to me is to use G10 as a backing plate and instead of drilling through the hull for the bolts would be to place studs in the backing plates.

Does anyone have any idea of how to tell whether the threads in the skin fittings are NPST or BSPP?

Thanks in advance.

[Chotu]

if you end up needing them…

i have at least one Groco thru hull and Seacock if you’d like it/them. i’ll get you the exact models. For you? Free.

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