Metal Bilge Keels - rusting - how best to treat the rust ?

[Capt Popeye]

My Hardy has steel bilge keels, they are showing signs of rust as the Anti Foul wears away - so whats the best treatment to apply directly to the bare metal to stop the corrosion before applying metal primer please ?

Thinking of using Primacon Metal Primer as the primer

All suggestion most welcome

 

[Concerto]

Fertan is my choice on my iron keel. Then coat with 5 coats of Primacon before antifouling.
Fertan – Rust Convertor

 

[Capt Popeye]

Fertan is my choice on my iron keel. Then coat with 5 coats of Primacon before antifouling.
Fertan – Rust Convertor

Thank you Concerto much appreciated

 

[rogerthebodger]

Grit blast or needle descale the surface.

Paint with hydrochloric acid until ALL surface shows a uniform gray colour. Then wash down with fresh water and dry. Pint with phosphoric acid and allow to dry.

Paint with at least 2 coats of epoxy tar with no more than 48 hours between coats. More coats the better.

Then antifoul of your choice.

 

[neilf39]

Another vote for fertan.

 

[PabloPicasso]

yes. fertan. i find there are always rust spots no matter what I do each year. So just treat with fertan and anti-foul over the top

 

[rogerthebodger]

i find there are always rust spots no matter what I do each year.

Rust spots will always return unless you remove ALL rust.

That's way I use Hydrochloric acid to chemical clean the steel and phosphoric acid to convert any remaining rust which there should not be anyway. This also gives a protective layer until a proper protective coating is applied.

This was a rusty service on my steel boat that has been needle descaled and had Hydrochloric acid applied but is still not satisfactory as there is still black iron oxide.

This is the same section that has had further needle descaling and Hydrochloric acid applied. This is not ready for epoxy primer. If it was below the waterline I would use epoxy tar.