How thick is my hull?

[Jim Walsh]

When I installed my refrigeration system last fall it required replacing my existing galley sink drain seacock and through-hull. The system included a ball valve (yeah, yeah, I know it’s a downgrade from a Spartan seacock) and a through-hull which is a heat exchanger since my unit is water cooled. The existing seacock and through-hull were removed as one unit by using a hole saw to drill up through the through-hull flange from beneath the hull. The new hole was slightly larger in diameter than the original.
Yesterday I heated the seacock with a torch and used a pipe wrench (comically large, like the ones the Three Stooges would use on each other’s noses) to finally separate the seacock from the remainder of the through-hull.
I though someone might be interested in the thickness of the hull so I’ve included a photo with a ruler held against it. The hull is 3/8” thick and the backing plate is 5/8” thick. You will note that the backing plate is made from a scrap piece of bulkhead which has a teak veneer on both sides. It was in perfect shape with no voids or evidence of water penetration. The section of hull was also in perfect shape with no indication of dry spots or voids. It’s always reassuring to see evidence of a well built structure.
The seacock was also in perfect working order after 35 years of service. I’ll clean it up, grease it, and reassemble it.

[Typhoon4Fun]

Thanks for posting! I have a thread up about trying to decide whether to overhaul my seacock backing plates. Helpful to see that it is indeed possible that they are as sound as they appear to be after all these years.

[fmueller]

So Jim ... that thin black band ... is that super heated igneous rock dust from when the asteroid struck the Yucatan and all the dinosaurs died ??

[Jim Walsh]

It’s primordial ooze. Cape Dory’s premier through-hull bedding compound.