Keel Re-coating

[DougM]

I just finished grinding all of the original factory coating off the keel of my 323. It is now down to bare iron. The coating had started to blister and crack evidently as the result of an original keel manufacturing defect. Unfortunately, Beneteau would not acknowledge responsibility, and evidently the keel supplier went bankrupt..

What I found under the relatively good parts of the coating was minor oxidation in the pores of the iron casting which may not have been properly cleaned before the original coating was applied. Now my question is, other than wire brushing with a citric acid solution, is there a better way to get the oxidation out of the pores in the cast iron?
sand blasting is not an option here.

I am preparing to apply several coats of Interprotect 2000E and I want to be certain that it will bond properly



This is what the keel looked like last spring before launch, as I tried to get one more season out of it.

 

[Ron20324]

HI DOUG. I HAVE MY 2006 B323 up on the hard right now. In previous years I used the stuff that neutralizes the rust and stops further action. I thought I had some, but can't find it, so off to the hardware store for more. Thankfully(?) Andrea is raining on my boat all day, so I get a much-needed rest. Are you staying with the Gori porp/pitch? Ron

 

[Jackdaw]

I use the POR-15 system on my Iron Keels. Love this stuff.

http://www.por15.com/

 

[Gunni]

I use the POR-15 system on my Iron Keels. Love this stuff.

http://www.por15.com/

That stuff seems to be amazing, but I don't see where they list application for submerged marine use or compatibility with anti-fouling paint.

Definitely going to try the tank sealant in my old farm machinery.

 

[DougM]

I looked up that product, and It would be incompatible with the Interprotect 2000E.I need to get the iron super clean so that the 2000E will adhere properly. Cast iron is not good at holding any kind of finish if it's not free of oxidation.

 

[Beneteau 321]

One option would be to have keel sand blasted to bare meten then coat

 

[cymeyer]

I use VC17. Works great.

 

[DougM]

Keel is already down to bare iron, sand blasting was not an option. The bottom paint was not the problem, the substrate was detaching and blistering off the iron. The original question was whether anybody knew of a solution other than citric acid to clear the light oxidation out of the pores of the cast iron.

I agree that VC17 is good, I have always used it on this boat. However, it probably wouldn't protect bare iron let alone stick to it. The objective is to get a solid bond between the iron keel and the Interprotect2000E that is applied prior to coating with VC17.

 

[Captn TJ]

Interlux makes a primer for bare metal. Also the copper in bottom paint in direct contact with the cast iron will accelerate the corrosion process - so smart move using a barrier coat like 2000.

 

[DougM]

TJ, I used Primocon for a section repair on the keel bulb about 4 years ago. When I did strip the keel, that area had held up remarkably well. In fact that area was the most difficult to strip, that material was almost like a plasticizer. I had about 5 coats of it and that small area and it was a devil to get off with a rotary wire brush and 80 grit on a sander.

 

[py26129]

That stuff seems to be amazing, but I don't see where they list application for submerged marine use or compatibility with anti-fouling paint.

Definitely going to try the tank sealant in my old farm machinery.

I'll second Jackdaw's recommendation. I used POR15 on the cast iron keel of my PY26. It held up extremely well until I sold the boat, about 10 years. I would not hesitate to use it again.

One word of caution: Make sure you don't get any on your hands (unless you like the color). It will be there for a while

Cheers

Matt