Where the
world gathers for metal finishing
Q&As since 1989


-----

Seaside steel sculpture in serious situation

We have a seaside sculpture which is made of weather resistant steel, but is corroding. What can I do to treat the steel in order to prevent further corrosion?

Maurice Kelly
- Brighton, England
2003

---

2003

Dear Maurice,

Assuming you want your statue to continue to look like steel. Then a couple of options like painting it or having it galvanized are ruled out.

Your best bet is Cathodic Protection (do a search on this). Corrosion is a electrical circuit, at the moment it's going one way and your steel is corroding. You can drive it the other way, but that takes an external power supply (DC), or you can bury a more active metal (zinc, magnesium) near by and wire that up to your statue. The more active metal will corrode and protect the steel (eventually you'll need to replace the zinc or whatever you used). The chandlers in your area should be able to help you out, the same method is used to protect steel hulled yachts.

Ian Brooke
university - Glasgow, Scotland

---

Here in the USA we have a product called "Ospho [affil links]" I think the main ingredient is phosphoric acid, it will stop rust for years and will not hurt most painted surfaces.

Bill Mashburn
- Hermiston, Oregon
2003

---

Maurice,

What Ian says makes eminent sense ... even for outboard engines (on fibreglass boats) one has or should have some 'sacrificial' anodes for the salt chuck (i.e., seawater).

Maybe after putting in the (accessible!) anodes and after cleaning the steel, maybe a coat of a clear u.v. inhibited lacquer coating might also help.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).
2003