Thru hull backing plates

[britinusa]

While replacing the engine stop cable, I took a dozen plus pics from inside the the aft locker.
They show that each of the thru hulls have plywood backing plates  (more like washers ) about 1/4" thick. And they appear to be breaking down / drying out.

Most certainly they're original.

They're all above the water line.

Replace?

Paul

[Noah]

Maybe. Photos wiil not tell complete story. You need to poke around with an "implement" to check plywood wood intergrety. If good, then paint to seal. Otherwise....

[KWKloeber]

pics??

[britinusa]

Pics

[britinusa]

Another pic.

And link to album of them.
https://goo.gl/photos/jBeHGMD19HsqvceG9

Paul

[KWKloeber]

Paul,

I doubt you're in danger of sinking, but I see your concern.  If mine looked like that I'd probably put them on my A- or B+ list,

RC (maine sail) has an article on installing bronze thru hulls, but you might be able to glean some tips for yours. 

I would think that they would be an ideal application for G-10 (although a little pricey) but you could certainly use meranti ply and seal the faces with epoxy.

-ken

[Noah]

I believe you said all of those are above the waterline. Then my advice still stands: poke them with tool and check for soft wood. If ok, just paint. What does look somewhat shaky is rusty hose core wire and possibly the PVC elbow (but Ken will tell you if that's "bad" PVC).

[britinusa]

Thanks Ken, Noah.
The rusty one is my main concern too.

I followed Mainsail's process when I put the new thru hull for the A/C discharge. Made the backing plate from layers of glass cloth.

Will dig into it (no pun intended)

Paul

[KWKloeber]

good eye noah, I didn't zero in on the elbow.

If it's above WL, then, I suppose, "it's all good." 

But -- BIG <- that's a big "but", a great big beautiful but,  It's HUGE in fact.  Thru hulls are parallel thread.  A female NPT should not be used on a male parallel thread.  "Ever" - but since it's above WL, YBYC.

It is acceptable to thread a male NPT into a FEMALE parallel thread (noah -- such as that sink hose barb I sent.)  Just be very careful not to cross thread.

I presume those (some?) are cockpit scupper hoses?   They go out of sight, out of mine.  One of mine disintegrated and leaked at a most inopportune time, and contributed to a $400 diesel mechanic's bill (long "perfect storm" story), and a whole lot of headache and heartache and self *ss-kicking.


kk

I believe you said all of those are above the waterline. Then my advice still stands: poke them with tool and check for soft wood. If ok, just paint. What does look somewhat shaky is rusty hose core wire and possibly the PVC elbow (but Ken will tell you if that's "bad" PVC).

[Ron Hill]

Guys : I was told many years ago the reason for the plywood between the thru hull nut and the plywood was to act as a cushion between the curved hull and the flat surface of the nut.

It's somethin that needs to be checked at each haul out and re-splash.
 
From the pictures I'd say that these thru hulls needed to be rebidded awhile ago.

A thought