Seeking advice, corrosion mitigation.

[Kenatsea]

Ok, here goes.

I went to Mexico looking at a SV that is for sale. I did not buy it, but through the kindness of some cruisers down there I was connected with a boat that was not officially for sale but might be available.

And so 2 months on I now have a nice project boat to spend my time and $$$ on while learning the cruising/sailing life style.

I was attracted to this boat (classic plastic) due to the prior owner had already completed a ton of upgrades. One of the upgrades was a recent re-power with a 27 HP Yanmar. One of the complications I am working through is the prior owner died ~3.5 years ago and the boat has been in the water in a marina and has had some maintenance from the local maintenance company.

I'll be heading down in a couple of weeks to complete the possession process, complete inventory of items, schedule a haul out and official survey.
I know, you are suppose to survey the boat first...But the guy whom recommended the boat to me as a potential good buy was the surveyor and the guy whom has been maintaining the boat all along. So I feel fairly comfortable with this situation.

I'm sure in the future I'll have a lot of questions for the community but I'm trying to prioritize the work required so I'll start with just one question.

Corrosion, I am assuming the zinc's are either almost or are completely gone as around the thru-hulls I have pretty blue copper-sulfate type build up at the connection (threaded) points. Same with the heat exchanger!

So my question is,

1) What is the best way to remove the corrosion?
2) Can I expect permanent damage, if not what can be done to repair vs. replace many of theses points of corrosion?

That's all for now, I'll try to upload some pictures.

BTW, I would like to keep the name of the boat out of the conversation to protect the prior owners family's privacy.

Many thanks again to most of this community for positive comments and replies.

Ken (sorry, I'll work on getting the pictures at the correct angles)

[Kenatsea]

Added a couple more pic's. There is even a little on the new (low hours but ~5 years old) transmission (seen in the prior picture's) .

Thoughts/advice will be appreciated.

[Kenatsea]

Just giving this a bump, still looking for some advice...thx.

[markwesti]

Hi , congrats on the boat . We get that blue dust too . I just brush it off with a stiff nylon brush and then spray some corrosion inhibitor .

[a64pilot]

I am a big fan of Corrosion-X, there are many others but Corrosion-X works well and is very easy to clean off too.

[markwesti]

1+ for Corrosion-X that is what I have been using for some time . Although Ken's engine prolly doesn't need it , but when I get some orange type rust I wire toothbrush the spot and then put on a primer (Permatex) that bonds with the rust that's left . And I found out that Krylon Hammer Tone sliver is a nice match for Yanmar silver . Also back to the blue dust I get that on the end cap of the heat exchanger , It's not leaking I feel it , it's dry but that blue dust builds up it takes about 2 yrs. to get to the point where I clean it .

[Don C L]

So the photos look like it is all brand new, but you are concerned about the thru-hulls, right? They are bronze with some blue-green growth on the threads right? Are the thru-hulls bonded? Opening and closing ok? Personally, it sounds like I would not worry about it but I'd brush/clean it off. I've seen some pretty corroded-looking bronze that just unscrewed no problemo with some super penetrating oil (can't recall the name right now!). I'd be more concerned about a pink color if you dig into the metal a bit. If you are going to haul her out anyway, replacing thru-hulls is not too bad a job, if you have any concerns.

[Sailmonkey]

I see nothing in those photos that even hints at being concerning.

[Kenatsea]

Thanks for the feedback. I guess to root of my concern was seeing some evidence of the corrosion at each thru hull location throughout the boat as well around the engine/water connections.

I'll just clean it up, replace the zincs and monitor.

[Sailmonkey]

Originally Posted by Kenatsea

Thanks for the feedback. I guess to root of my concern was seeing some evidence of the corrosion at each thru hull location throughout the boat as well around the engine/water connections.



I'll just clean it up, replace the zincs and monitor.

FYI, the zinc anodes will not deter the internal discoloration of bronze fittings. The zinc works by being immersed in an electrolyte (seawater) and being more active than the meter that it is attached to.

[rbk]

If the thru hulls are bonded make sure the wiring is in good condition. If half are corroded or disconnected the remaining bonded ones will take the brunt. All or none with that. Some will push for none but a lot depends on where you're moored and how well the neighbours and harbor takes care of their elec systems.

[Cheechako]

Some green corrosion on bronze is no problem. Bronze forms cuprous oxide corrosion which protects it. Big hairy fuzzy corrosion would be a problem. The other thing is: are the thru hulls bonded with wires to the zinc and each other? some are, some aren't. ZIncs wont help the fittings if not bonded by wiring.
One thing I would plan on if I were you, is inspecting and repacking the shaft fitting. You say the boat sat for 3+ years in the water, what often happens is where the shaft goes thru the packing, the stagnant water sits in there and corrodes the shaft. Sometimes it will look like worms have eaten away at the surface of the shaft! If you pull the shaft, or even just disconnect and pull in or out a few inches to inspect, that would be a good thing. New packing on a corroded shaft will tear up the packing.
I have had this occur twice on boats that were sitting without use a long time. SO sort this out while you are out of the water!
Everything looks neat and tidy in those photos. The other thing to plan on is new fuel filters and what to do about cleaning the fuel that has sat that long. In Mexico, If you could find someone to pump and take the old fuel for free that would be a good thing. Not that expensive and often a problem once you get in the ocean. Well worth the cost as opposed to being dead in the water with gunk thoughout the system!

[Schooner Chandlery]

Congrats on the new boat! YEs--replacing the filters, impellers, and doing a quick clean up of existing corrosion will take you far. The bronze, if you wipe down any fuzzy stuff and like others said--make sure any pink doesn't go deep, you're likely all good. You can put a barrier on the bronze (like many of the compounds that mix wax and a bit of this-and-that) to help further corrosion there in the future as well. We've taken to painting bronze bits that go onto the engine and I wish we'd painted the bronze frame of the raw water filter as well. Again--good luck and congrats!

[JPA Cate]

You can actually work out ways to clean your own fuel, if you prefer to do that. It requires a lot of Jerry jugs, some spare fuel filters, and being able to pump out from your tanks, but is doable. If you prefer to "discard" the fuel, offer it to some Mexican who operates a fishing boat. If you can get at the inside of the tank, do what you can to clean it as thoroughly as possible, before re-fueling--there is likely to be years of grunge in there.

Ann

[Kenatsea]

Thanks for all of the tip's.

I'll be back down with the boat in a couple of weeks and will start on these projects.

Really appreciate the heads up on the prop shaft, did not think of that but a very good tip.

I'll definitely be sure to double check and service the fuel supply and filter system.

I have a lot to do before even casting off. It will be hard to keep my patience in check.