Catalina 27 - Old Through Hulls

[Whaler Jay]

I recently purchased a 1977 Catalina 27. I have been slowing making upgrades and getting her back in shape. The boat is out of the water. I have taken out the Atomic 4 and have brought it back to life. I have a new fuel tank and holding tank on the way. The hull and below and above the waterline are being painted. I have many other projects(electronics, sails and other cosmetics).

That’s just a bit of background for a question I think I already know the answer. The through hulls are all original, head intake and outflow, sink, and engine raw water intake. If the can remove the old ball and gate valves(and the through hull fittings/nipples don’t spin) can I replace them with Groco bronze marine ball valves? And leave the original through hull fittings, which are bronze.

I searched this topic and the major consensus was to replace them with proper through hull fittings. The boat was in the water when I bought it, but I certainly don’t want one or more to fail when I put the boat back in the water.
As I am sure you all know, the list of projects grows as does the expense with any “new” boat. As I type this post I know I should make the through hulls a priority. I just thought I would ask if anyone has updated the valves only and been satisfied with the results?

Sorry for the long post with a seemingly obvious answer, I want a safe boat and just wanted to get some opinions.

Thank you,
Jay

 

[Ajay73]

Jay, I own a 1980 C27 and have replaced all the through hulls. The job is really fairly easy to do. Cutting out the old nipples is the hardest part but is not that bad when you figure out the simplest way to do it. The original glassed-in nipples on my boat were very well bonded to the hull and would have lasted many, many years to come but I opted for the "right" way and removed the nipples, glassed in backing plates and installed flanged seacocks. The cost wasn't too bad but you are right in that upgrading an older boat does add up. If you have any questions as to the job of putting in new through hulls let me know.

 

[kito]

If your gate valves were like mine, you will have to cut them off. I could not turn mine no matter what I tried. I found an oscillating saw with a metal blade was the best choice and cut the thru hull fitting just below the valve. I am using a standard Groco thru hull, a nps thread tailpipe adapter with hose nipple. I need to find a ball valve still. The problem is the thru hull threads are nps thread and most ball valve are npt threads. I heard since it's not under high pressure that they can be used together with lots of tape. I rather not try it. If I had to do it again I would just get the correct thru hull and use the flanged ball valve instead.
Btw, if you don't have a oscillating saw, get one. You will find it the most useful tool during your project. I love mine.

 

[Whaler Jay]

Thank you for the replies, and you helped make my decision easier! I didn’t even think that the new ball valves might not be the same threads as the originals. I do have all the tools and it seems like the thing to do since I am being diligent with other aspects of the boat. So on your raw water intake for the engine you don’t use the through hull with the outside strainer(the scoop)? I think most of the through hulls I have seen use that use the flanged through hull do not have the scoop, maybe a hinged strainer?
Thank you,
Jay

 

[Stu Jackson]

Why External Strainers are a Bad Idea 101 (Maine Sail) http://forums.catalina.sailboatowners.com/showthread.php?t=124964

 

[dive7mmwet]

The thru hulls are not too bad to do I bought a grinder like thing that reciprocates less mess and one blade got it cut off in no time a bit of grinding (WET ) and we were ready to install a new one

 

[Whaler Jay]

Thanks for the replies and advice, I am going start taking the old ones out first thing in the morning.

 

[jrowan]

I think you know what a priority it is to remove those old gate valves which Catalina never should have installed in the first place. They can leak & fail at any time. I was under the impression that in the 1970's Catalina was just using standard household copper plumbing pipe & glassing it in directly through the hull during the glass lay up, & that these where not even proper thru hulls with flanges on the inside & outside of the hull penetration. You may be able to tap threads onto the existing copper pipe, but be careful as it gets thin & weakened by corrosion over time. Obviously this work is best done when the boat is out of the water, so if you have a problem you won't sink your boat. Good luck.