Catalina 34

General Activities => Main Message Board => Topic started by: ewengstrom on November 08, 2023, 07:59:42 AM

Title: Rebedding thru hulls
Post by: ewengstrom on November 08, 2023, 07:59:42 AM
The boat is on the hard and I'm actively beginning on below the waterline maintenance and repairs.
One project is to remove the thru hull just below the drain on the cooler. It is covered up by cabinet modifications and is now unusable, so I'm removing the thru hull and glassing it over.
I removed the ball valve and backed the nylon nut off to the top of the threads and gave it a tap with a rubber mallet.....and it just popped right out....heck, I could have just pushed it out of the hull with little effort, the sealant was just not holding on anymore.
It never leaked, but there wasn't much holding the water back either.
Given how easy it was to remove I decided to re-bed all of the other 5 thru hulls too.
Two more came out the same way, two were a bit more difficult and one required some real effort.
Sooooo....even if yours don't leak, if the sealant is anywhere near 35 years old, it should probably be on your to-do list upon your next haul out.
Title: Re: Rebedding thru hulls
Post by: AndyBC on November 08, 2023, 08:18:55 AM
Thanks for the heads up!  Interesting that they never leaked, but were so easy to remove.

Which thru hull was the most difficult to remove, the macerator?

Did you replace them all with new marelons?  4200 to seal?

Title: Re: Rebedding thru hulls
Post by: KWKloeber ‘84 C-30 #3573 on November 08, 2023, 08:53:37 AM
WOW. I suppose that might be the ultimate (35 yr) out of sight, out of mind!!
Title: Re: Rebedding thru hulls
Post by: ewengstrom on November 08, 2023, 04:06:16 PM
I am replacing all the thru hulls in the boat, these Marlon ones look just fine but after 35 years of use I believe they are inexpensive enough to warrant replacing them just for peace of mind.
I'll re-bed with 4200, I believe it's the correct sealant for this application.
All the ball valves operate well so the plan is to lube them and reinstall.

On another interesting detail I noticed,  look closely at the recessed area where the thru hulls reside...that's shiny gelcoat!!!! I'll be roughing these areas up to give the caulk something to grab onto, I'll also rough up the back side of the thru hulls for the same reason.
Title: Re: Rebedding thru hulls
Post by: Ron Hill on November 10, 2023, 02:31:55 PM
Eric : You did a good job, but if they weren't leaking and the nylon nut was snug - they weren't going anywhere!!

My thought
Title: Re: Rebedding thru hulls
Post by: ewengstrom on November 13, 2023, 05:05:26 AM
Ron,
You are correct, they were not leaking and might not have ever posed a problem...but if you'd seen how easily three of them popped out I would venture that you too would also take the time for the simple task of re-bedding them while the boat is already out of the water. I didn't mention it in my first thread, but one of them must have leaked along the way somewhere in the past, it had a tannish colored sticky sealant instead of the caulk as the other five had. So they can leak.....I believe.
Title: Re: Rebedding thru hulls
Post by: Ron Hill on November 13, 2023, 02:26:27 PM
Eric : Like I said "if the nylon nut was snug"!!  Your boat your choice.

Guys : With Erics experience, Just check to make sure that on thru hulls that are NOT leaking - check to make sure that the nylon nut is tight!!

A thought