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Previous Reversing accident ... Check your bolts sailor!

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Re: Previous Reversing accident ... Check your bolts sailor!

Postby yukonbob » Wed Nov 21, 2018 1:42 pm

Whoops! Guess i should check in more frequently!?! :o I see its been sorted out more or less, didn't mean to set of a firestorm lol. I skimmed through the replies and it is possible that the bolts were all sealed properly and one was loosened somehow and allow water to penetrate around the bolt and from the pictures it appears not all the way but mainly around the bolt head. Also to add to "Additional info from same site.
Crevice corrosion is only likely to be a problem in stagnant solutions where a build-up of chlorides can occur. The severity of crevice corrosion is very dependent on the geometry of the crevice; the narrower (around 25 micro-metres) and deeper the crevice, the more severe the corrosion. Crevices typically occur between nuts and washers or around the thread of a screw or the shank of a bolt."
as the crevice is created it allows more water further in along the bolt (for instance) then the water stagnates and the process continues until it fails or enters the hull (extreme).

Here is a good article on marine corrosion. About half way down is crevice corrosion, see the similarities in the bolt pic there and the one poster here?
https://www.boatus.com/seaworthy/magazine/2015/july/marine-corrosion-101.asp
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Re: Previous Reversing accident ... Check your bolts sailor!

Postby yukonbob » Wed Nov 21, 2018 1:53 pm

One more with a little more technical data :) Replace SS bolts every few years. keep water out (this is absolutely key), and don't forget to use an isolator between dissimilar metals and similar metals like permatex or tefgel especially SS on SS nuts bolts etc.
https://sassda.co.za/stainless-steel-and-corrosion/
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Re: Previous Reversing accident ... Check your bolts sailor!

Postby yukonbob » Wed Nov 21, 2018 2:07 pm

Neo wrote:That's interesting Ray and I don't really know either way but I do know that swing mooring (in Australia) do not allow SS Chains. From what I understand if the chain lies in the mud it corrodes ... Is mud more or less Oxygen? :|


Just re-read this. SS for mooring is bad, whether chain, swivel etc as SS can a) develop micro cracks and b) catastrophically fail (sudden and without warning) where galvanized chain and fitting do corrode from the outside at a faster pace they are less prone to catastrophic failure and will wear, elongate over time (hence the need for regular inspection)Google SS anchor swivel failures; It is highly recommended to avoid these. To sum it up SS is brittle and hard to weld (Chain welds on every link), galv mild steel is not so much.

The mud thing...depending on what the content of the mud is you can create a galvanic cell if the mud contains the right mixture. There are several locations on the Alaskan and BC coast that do this, only real drawback is your ground tackle turns black (where it is in the mud) and stays that way for a month or more. In theory it could corrode your ground tackle much worse but the concentrations I imagine would have to be much higher.
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Re: Previous Reversing accident ... Check your bolts sailor!

Postby Neo » Wed Nov 21, 2018 4:28 pm

yukonbob wrote:To sum it up SS is brittle and hard to weld (Chain welds on every link), galv mild steel is not so much.

I keep hearing this but when I weld with my little TIG welder SS is my favorite metal... Get the current right and you can make it flow like solder on a soldering iron :)

Thanks for all the info Yukonbob :wink:
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Re: Previous Reversing accident ... Check your bolts sailor!

Postby slugbug » Thu Nov 22, 2018 10:17 am

Just wondering should I use galvanized chain for the anchor? I currently use about 10 feet of it with 200 feet of rode, should I use more chain? I mostly sail on lakes and rivers but intend to do sailing in salt water in the next few years. I do not have anti fouling any recommendations on what to apply? Thanks
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Re: Previous Reversing accident ... Check your bolts sailor!

Postby yukonbob » Thu Nov 22, 2018 3:26 pm

Yes to galv chain and bottom paint only if you really plan on leaving in for more than a week (unless you’re in a high growth area a week maybe too long) I had good luck with interlix fg bottomkote on the Mac. If you do plan on doing it I would recommend a barrier coat (epoxy with additive) unless you want to sand all the paint off in the future.
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Re: Previous Reversing accident ... Check your bolts sailor!

Postby slugbug » Fri Nov 23, 2018 11:28 pm

Yukon Bob Thanks for the reply RE: chain, I will stay with that. I have never used bottom paint cause I'm in fresh water. I did have a problem with zebra muscles last year in Lake Michigan and they were very hard to remove. Would bottom paint prevent that?
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Re: Previous Reversing accident ... Check your bolts sailor!

Postby yukonbob » Sun Nov 25, 2018 1:13 pm

Yes it will help but it’s also not a set and forget item. You’ll still have to clean but it can be done with a pressure washer rather than a scraper. Real problem with muscles/barnacles etc, it they can break through the gel coat into the laminate and cause real problems.
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Re: Previous Reversing accident ... Check your bolts sailor!

Postby Ixneigh » Fri Nov 30, 2018 7:59 am

Stainless corrosion is a fact of life in sea water.
For what its worth, I have a bunch of zinks on the outboard bracket. I see a white haze on all my steering gear metal. The zinks are protecting all the metal back there by feeding hungry stainless some free electrons.
Use the best stainless you can for critical stuff. I intend to beef up the lower Gudeon, increase the fiberglass thickness there, and use larger bolts, at some point. I will order those bolts from someplace online that sells high grade SS.
SS is a no no for any anchor hardware except on boats that never cruise. You don't want to sit on SS tackle for weeks, or months. Good grade galvy stuff is best.

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Re: Previous Reversing accident ... Check your bolts sailor!

Postby Neo » Fri Nov 30, 2018 1:41 pm

Ixneigh wrote:I have a bunch of zinks on the outboard bracket. I see a white haze on all my steering gear metal. The zinks are protecting all the metal back there by feeding hungry stainless some free electrons.

That's additional ones to the regular ones that are on the OB?... If so can you post up a photo?
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Re: Previous Reversing accident ... Check your bolts sailor!

Postby yukonbob » Fri Nov 30, 2018 8:16 pm

Watch over zincing. There are consequences in doing this. The white powder on the SS is a sign of over protection but on Macs the consequences are somewhat minimal due to no metal thru hulls, wood coring (transom only) and trailerable boats not normally having a true alblative high copper bottom paint. More isn’t always better
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Re: Previous Reversing accident ... Check your bolts sailor!

Postby Ixneigh » Thu Dec 06, 2018 8:32 am

What are the negatives?

FWIW I always use outboard motor antifouling on the whole transom to keep copper away from the outboard
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Re: Previous Reversing accident ... Check your bolts sailor!

Postby yukonbob » Thu Dec 06, 2018 4:25 pm

Ixneigh wrote:What are the negatives?

FWIW I always use outboard motor antifouling on the whole transom to keep copper away from the outboard


Too much protection can result in caustic attack to wood, a loss of anti-fouling paint or other underwater coatings on metal fittings, caustic corrosion on aluminum boats, and the embrittlement of high strength steel. Again over protection consequences on Macs are minimal.
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