C30 Thru Hull Replacement

[Ken13531]

I am looking for instructions on how to replace the thru hulls in my1987 C30 MkII. Hull# 3946.I recently purchased the boat and for me it is my first big boat purchase.The surveyor made note that the plastic like Thru Hulls should be replaced as they are getting old and could break off as they become more brittle.I had looked at thru hulls in the Marine store and it looked to be a pretty simple task until I get to starting the job.It looks like there is simply a plastic flange which is then held in place by a big nut. This nut is then fibreglassed in place on the inside of the hull.Then there is what appears to be a plastic nipple threaded into this flange on one end with the other end of the nipple threading into the seacock valve.Does anyone out there have instructions on replacing with Bronze thru hulls and bronze valves? Photos would be great.I have looked at a couple of articles and links from this website but they still leave me wondering. I don't want to start cutting good fibreglass work out of my boat if it is not required.

 

[Richard4728]

Thru hulls

Ken,I have an 87' also,(#4308)I believe mine came with the Marelon Valves(black). Although I may be wrong, I haven't heard of these valves going brittle and IMHO going to bronze would be creating headaches for yourself. If necessary I would replace the existing with a Forespar Seacock(see link). Have you tried a little vegetable oil on the ball part of your existing valves? If the valve is bad, just spin the body off and replace it with a new one and you won't have to touch the thru-hull.Good luck!

 

[Trevor - SailboatOwners.c]

Marelon thru hulls

Hi Ken -I'm with Rich on this one; you shouldn't need to replace the "plastic" marelon valves just because they are from 1987. In any case, the thru hulls should not be glassed into the hull. However, they could be sealed with 5200 or similar permanent compouind which required literally breaking them out of the hull. This would destroy the thru hull but not damage any surrounding fiberglass. I'd take a close look at the valves and determine what, if anything, needs replacing before going after them with heavy equipment (believe me, you'll have plenty of other projects to do!).Have fun with your new boat!Trevor

 

[Tom S]

I agree totally with Richard

Are they "plastic" which in my mind are very very dangerous below the water line or are they "Marelon"? -- Which is close to indestructible as a through hull can get (Though I have heard the handles on the "sea-cocks" breaking on old models)Go back and ask that surveyor if he noted if they are Marelon or not? If he doesn't even know what Marelon is or never heard of it then might be ok.When I first bought my boat I wasn't sure I liked the "plastic thruhulls" but after owning the boat 5 years and learning more I am very happy to have Marelon. If I got a new boat I might specify Marelon. There is a lot of positives going for itMany Steel and Aluminum boats uses Marelon when they don't want to weld in a "Thru-Hull Pipe"

 

[Rob 1981 Cat 3019642]

Something to consider

Are all the thru-hulls plastic? If the above-the-waterline ones are plastic, OK. If the below-the-waterline ones are plastic, they should be replaced with bronze.Lots of guys here are happy with the Marelon valves, but I have replaced all old rusty cheap metal valves with the bronze type.(prev. owner used hardware store ones). Peace of mind. Whatever makes your boat float! See the link for the work I did on mine.PS How does one sail a C30 in Edmonton? Do you wax up the bottom of the keel and ski it over the frozen N Sask. River? I moved away from there because there was no water!

 

[Bob]

Why Replace Them?

I own a 1988 C-30 and have the same valves. Consider that Catalina would not use a cheap plastic thru hull valve on these models. Replacing all these valves (lets see, engine cooling intake, sanitary discharge, sink/cooler discharge, head flush intake, sink/head drain...did I forget any?). Replacing them takes time, effort and expense. You can call the Catalina factory and they will advise you what they used. If you bought a depth sounder or knot meter you will see that plastic thru hull fittings are used. For my money, I would put it in other improvements or upgrades on your 30. On the interior valves keep in mind one very critical rule for any vessel: DOUBLE CLAMP YOUR HOSES. And make sure they are stainless steel clamps. Replace any that are rusted. The Catalina 30's have been around for decades and they use premium hardwear and fittings on their vessels. Next time your aboard, locate every thru-hull (starting in the head access panel to the V-berth), check the clamps for tightness or rusting (replace immediately)and carefully open and close the valve several times to "exercise" them a bit. A thread was run on here last year on just how to lubricate these if the handles were tight. Opening and closing several times a year should be on your maintenance schedule. After all how often do you open or close the sink drains or the head flush intake? On most thru hulls a small "donut" made of wood is placed inside the vessel to anchor down the male end. If you use 3M 5200 adhesive consider them their for the life of the boat! The best insurance: double stainless clamps, and and a bag of wood thru-hull plugs. Now, take a look at the intake for the engine cooling and that little strainer thats clamped in-line. Thats a whole different topic!!RegardsBobBreezin IILake Lanier, GA