Preparation of iron keel for epoxy application

[RBilly]

I have an'83 O'Day 28 with an iron keel on Georgian Bay (fresh water).
I am going to strip the keel to bare metal and apply 2000/2001 before launch this season
to hopefully hold back rust. At present there is only mild rust after each season.

We have a product available at Canadian Tire called POR 15 Metal Prep. I have used Pettit's Metal Prep 6980 up to now but no Interlux epoxy before applying antifouling paint.
I am looking for a product to apply to the bare keel to seal it from moisture before applying Interlux 2000/2001, then antifouling.
Any suggestions of teqniques, products would be appreciated.

 

[dlochner]

What does Interlux recommend? It is generally best to stick with a single brand when applying barrier coats.

 

[Tom J]

I used West System epoxy to seal the iron keel on my O'Day 23. West Systems gave me list of products they approved to seal the iron before applying the epoxy.

 

[Charlie Jones s/v Tehani]

I tried the WEST stuff. It rusted. I have had excellent results with Interlux Interprotect 2000. 8 years and was great at last haulout. I sand blasted the cast iron keel.

 

[Davidasailor26]

+1 for just using the Interlux. Applied to the right number of coats it should seal out the moisture.

 

[Gunni]

It is important to prep and treat the surface in one step. Get the keel down to bare metal and give it a coat of Ospho to convert any remaining rust including micro-rust. Then begin your Interlux 2001 primer build up. You want 10 mil. Very important that you follow the coating sequence as this is an epoxy product, you want a chemical bond.
http://www.ospho.com/

 

[Harlan]

15 years ago (just looked it up - where did those years go??!!) I stripped my OD34 cast iron keel, coated with Interlux 2000, faired with WEST epoxy and thickeners, then more Interlux 2000, then Baltoplate and wet sanded. Nothing more than sanding the Baltoplate and repainting since. Boat is raced and bottom, keel included, is in excellent condition. I don't recall how many coats of Interlux but I'm guessing 4 to 6 before fairing and another 4 to 6 after. Immediate coating (within hours - not overnight) of stripping the cast iron was important. I stripped and coated in sections as the stripping took many hours. This system has held up great for me.

 

[isaksp00]

I used POR15 when I did my H23 iron keel. I did use their 2 part surface prep. The grey protective coat goes on pretty easily and is smooth. I have had some pockets of rust appear, maybe 2 or 3 inches across, used in fresh water only. Interlux looks like it may be more complex to apply (it is 2 part, right?) but seems to be more robust.

 

[dlochner]

Proper surface prep is essential for keeping an iron keel rust free. That and not hitting anything that would violate the coating and allow water to come in contact with the iron.

This video from SV Seeker youtube channel talks about issues protecting steel from corrosion. It is probably longer than is needed, but there is good information there.

Here's a link to the Interlux Tech Info for Interprotect 2000e. Follow the directions for Steel.
https://s3-eu-west-1.amazonaws.com/..._eng_usa_A4_20141215.pdf?mtime=20170914095537

 

[Mechone]

I used the 2000e every year on spots and like I said every year more rust . Last year por15 metal prep, then por 15 and then 4 coats of 2000e. I then added 2 anodes either side ( tear drop) ,hauled after season no rust. I read online of a fellow doing this and had gone 8 years no rust. I believe por15 metal prep is the same as ospho it converts the rust ,turns black

 

[isaksp00]

Mechone, I am thinking of grinding out my rusty spots and using Ospho, then Interlux on top. But not removing where the POR15 is sound. Did you find the Interlux adhered well to the POR15, and did you do any prep to the POR before applying Interlux?

 

[Mechone]

Mechone, I am thinking of grinding out my rusty spots and using Ospho, then Interlux on top. But not removing where the POR15 is sound. Did you find the Interlux adhered well to the POR15, and did you do any prep to the POR before applying Interlux?

The interlux 2000e went right over the por15 no problem ,on my last coat of 2000e while still tacky and painted on my interlux micron as someone told me it is hard to get micron to stick when 2000e is dry ,worked good

 

[Gunni]

Applying bottom paint ‘hotcoat’ on the last coat of the epoxy primer is good practice. Makes a strong chemical bond into the epoxy.

 

[isaksp00]

I wish I could lightly sandblast the keel to roughen the hard smooth surface of the POR, but maybe that isn't necessary. At least I don't have to worry about antifouling paint as all I get in our lake is some slimy gunk that the yard can blast off.

 

[Crazy Dave Condon]

Iron rusts. As a dealer I applied zinc chromate but now incorporated in other solutions is the case. It worked to prevent rust and then applied barrier coats. Never an issue after that