NP336 wrote:
I need to replace my thru hull and sea clock that’s located under the galley sink. I’ve have greased the ball fitting for the last 3 years since I’ve owned the boat, and it’s a bit better, but it’s still very stiff.
I want to replace to meet ABYC standards, that has a triangular base and a backing plate.
Here’s my questions..
1.) My existing seacock is not bonded. Can this be done with a new one? What do you bond to ?
2.) I think the galley sink thru hull is one and a half inches but not sure.
3.) Should I go with bronze or Marlon?
I’m leaning towards bronze but not sure which type/brand /model is the suited for this thru hull.
Thanks in advance for any and all feedback, advice, & comments.
Nick,
S/V Angela Mia
#336
Lake Superior.
Well, Tartan did not originally install it to current ABYC standards and I do not know precisely what is required in the latest regs. I am not sure why you would need to follow them for this. I would use the instructions in Nigel Calder's maintenance book. ABYC specs change fairly frequently. One thing is that you cannot use any wood or porous material for a backing plate as Tartan did. Tartan used (at least on my hull #373 Groco flush mount through hull fittings with marine ball valves on them--also I believe a no no in current ABYC--but most of the lobster boats ignore this and pass inspection and have a great deal more electrical abuse than your boat. I have replaced all of mine with essentially the same thing, but used a piece of laminate for a backing plate. The Groco Flush through hull fittings are a bitch to remove. You can try to turn them out with a special step wrench from the outside (you will need to expose the whole outside of the fitting which is likely buried under layers of paint and maybe some glass if you have flush mounted ones. I did not try to "save" the hole for the through hull. I ended up drilling the suckers out, refilling and glassing over the holes and starting all over again to make it all new and clean--and I made all except the sink drain larger (I think it was 1" ID) It is a big job. I would not recommend merely replacing the ball valve if that is the arrangement you have and putting it on the old through hull fitting. The through hull fittings are a weak point and corrode. I had a pinhole leak in one of mine that bugged me for a year til I found it under the sink. This led me to replace them all.
Using marine ball valves like Tartan did is probably not ABYC approved, but I think it is the right way to do it in this particular boat. They may look like the valves you see in Home Depot THEY ARE NOT. You need the marine type they sell at Defender and Hamiltons. The other challenge is that the pipe thread on the through hull fitting (male) is slightly different than the female on the ball valve. I think it will work, but I took mine to a machine shop and had them adjusted to perfectly mate--it can be done with a tiny amount of rethreading the through hull fitting in a couple minutes--this may have changed and the threads may now match, but check them and do not just force them on. If someone has installed the old lever valve through hull fittings with the three bolts through the outside, I pity you and I cannot help you. These are probably what ABYC wants and I think they are ridiculous overkill and create an opportunity for more leaks. I probably have pictures somewhere if you get stuck. I can coach you through the process if you want to do what I did.
You can use your own judgement on bonding. Nigel Calder has gone back and forth over the years about the bonding and no bonding. The original Tartans had some of the through hulls bonded and some not. Some say bonding accelerates corrosion. The heavy copper wire in the bottom of the boat is most likely just to direct a lightning strike from the mast step to your engine and prop to minimize what it takes out elsewhere---in my boat they had tagged this to a keel bolt and the strut, but this was not really for bonding purposes. I have owned my boat for 28 years and sailed a lot (lived on it for a couple years) and never had an issue that I thought bonding would help. But maybe I was just lucky. I think it is good to look at ABYC requirements (if you can figure which ones apply to your boat) but you also need to use your head to do what makes sense. Nigel Calders maintenance book is generally my go to, but he has recently gone over the edge with some of his stuff. I guess he needs to write articles to keep food on the table.
Let me know if you want some pictures. Removing the old through hull fittings was the worst part. I would consider doing more than one at a time. Maybe all of them. When the boat is out of the wather and you have all the tools there, I would not wait until they leak. Don't use 5200.
Ray Durkee