anchor rust

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M

mark

Has anyone had the edges of their anchor rust. Our 35lb. CQR anchor is rusting along the edges, and I am wondering what can be done? Thanks, Mark
 
Dec 5, 2004
121
- - San Leon, TX
two things...

First thing you can do(and the most expensive) is to look around a larger city for a metal shop that does hot dip galvanizing and have it re-dipped. Second thing is go to a good paint store that deals in machinery and truck/trailer paints and by the spray on galvanizing(95% if I remember), it will run about $8 a spray can, put on 3-4 coats, should last a season of light useage. A can should do 10-12 coats, depending upon size of anchor. There is really no need to spray over good existing galvanizing so a can might last longer. ...and yes you should do this. g'Luk
 
Jun 2, 2004
1,438
Oday 25 pittsburgh
Zinc...

Your anchor was originally galvanized. This was to protect the steel anchor from galvanic reaction. The problem is the galvanization originally on the anchor has worked itself out. The reason the anchor was galvanized in the first place was the zinc protected the steel because the zinc is a less noble metal than steel. In simple words, the zinc dissolved instead of the steel. You might try installing a zinc on your anchor. This could be a small outboard motor type of zinc. 3/4"x2" zinc can be installed by drilling, tapping threads and installing with stainless screws to the anchor. The reason things are protected by zincs is because steel rusts, and aluminum corrodes. This is mostly due to galvanic reaction. A battery works in the same way because ions move from one pole to the other on a battery. Salt water is an extremely suitable medium for galvanic reaction to occur. Thus you want sacrificial metal ( metal that will corrode and fail first) to protect your important metals on your boat. It is the same with your anchor. The zinc (galvanizaton)will be attacked before your steel anchor as proved by the failure of the galvanization that was initially applied to your anchor. I would install a zinc on your anchor. $2.00 for the zinc verses $100 + for the anchor. You can spray the anchor with cold galv. protectant(available at most diy stores) but I don't know how good this would work. If after installing a zinc, the rusting persists, find someone to hot dip galvanize it. This should still be less than purchaing a new anchor. Just about every yellow page should have someone that does this. If not call a place to someone that does plating and they should be able to tell you where to look. r.w.landau
 
Jun 4, 2004
629
Sailboat - 48N x 89W
1, 2, 3

1. A light sanding to remove any loose rust (there won’t be any). 2. Paint liberally with Phosphoric Acid (“Ospho”). 3. Burry the anchor in sand (go cruising). :) Gord
 
Jun 1, 2004
227
Beneteau 393 Newport
The key is

how often do you use the anchor? If you use it daily, the rust will be scoured off when setting it in the bottom, where it won't rust. If you don't use it regularly, put it in the locker where you won't see the rust. In either case, the anchor will last for many years with the edge rust with no ill effects Jim :)
 
Mar 18, 2005
84
- - Panama City, FL
Rusty anchor

I carry my 20# Danforth in a bracket on the stern pulpit, and decided one day that it would look a bit better painted white, which I did with a spray-on (something) chromate, commonly used for priming galvanized surfaces. Two coats resulted in a thick, slick, bright white finish with a surprise bonus: it came up from the bottom of SF Bay without a speck of the silty clay that previously added several pounds to the (manual) effort of getting it aboard. That was about ten years ago, and it is just now looking like it could use a touch up. One other note: the phosphoric acid mentioned above kills existing rust, but it serves only as a primer and will not inhibit future rust. Follow with a good topcoat 24 hrs. later.
 
S

Shorty

Ancient Danforth

My brother gave me an ancient cast Danforth retrieved from a shed behind his house. A little rusty, so I looked into hot dip galvanizing. Minimum charge etc $160. So that one, at least around me, is not worthwhile. Maybe I'll try the spray.
 
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