Keel protection

[Geno53]

Okay so I have the hull scraped and sanded down to the gelcoat and ready to apply my barrier coat and antifouling. But what do you do with the iron keel? Is it wise to sand down to bare metal if the existing paint is well adhered? There are a few rust spots but I guess i can fill and fare. By the way what do they mean by fare,(is the spelling correct).

After it is sanded and fared are you supposed to barrier coat it?

So many questions and so little time, the temps are slowly rising and I starting to feel the pressure.

[GordMay]

STEEL KEELS:

Before doing any work on a metal surface it must be free from corrosion, and it is essential to remove salt and contamination by high pressure (minimum 2500 psi) freshwater washing.
I always prefer to use coating systems* from a single manufacturer (*including cleaners, primers, & overcoats), and follow all directions meticulously.

JUST ANTI-FOULING:
Assuming the existing coating is sound and intact, and that you are overcoating with the same antifouling:
1. Wash the surface with soap and freshwater, remove any loose paint and allow to dry.
2. Apply two new coats of antifouling.

FAIRING, PRIMING, & ANTI_FOULING:
For areas where the coatings are damaged, filling, fairing, and priming may be necessary before application of primer and antifouling.

1. Shot blast or abrade (100-240 grade abrasive paper) to bright metal.

2. Remove dust and grit by brushing, vacuuming or using dry compressed air.

3. Wash with soap and freshwater.

4. Allow to dry.

5. Spot prime and fill where necessary using appropriate materials. I recommend about four coats of epoxy-paint, to a thickness of appox. 40 micron. Bare metal must be primed with Primer, immediately after surface preparation to avoid contamination and surface deterioration before coating, and to obtain maximum adhesion to the surface. Check surface temperature before coating as metal surfaces are prone to varying greatly from the ambient temperature.

6. Fair areas which have been filled, apply further coats of primer to encapsulate the filler.

7. Allow to dry fully before applying antifouling.

8. Start painting from tiecoat to appropriate manufacturer’s specification.

BTW: The term is "fairing", as in to make smooth and fair.

HTH,
Gord May

[BC Mike]

I have just done this on the Tanzer 22 that has an iron keel. I ground down to bare metal, squirted on metal ready and that makes the keel grey, washed off with water, let dry and painted with POR 15. The POR will dry when it is damp and raining or below zero. Wonderful stuff. It does not allow water to intrude and is smooth when it dries. So I painted the hull below the waterline with it. Then I used Everglas waterproof filler on the keel and to fix any divots in the hull. Sand and fill and sand and fill as required. More POR and then the bottom paint. Three different brands but they work. Biggest problem is getting the deck paint to dry at this time of year. The filler and POR are available at Lordco so do not get the marine upgrade in price. The above system has been working to good effect on my T8.5 for several years.
Michael

[Geno53]

Thanks everyone as usual all the info is good. Im glad i don't need to take the whole keel to bare metal I have enough work left to keep me busy to July. I think I took on to many projects at once some things could have waited until next year.

[Alan Wheeler]

Just to help concise some of the above comments, If the paint system that is on there is good and sound, don't remove it. If it is blistering and rust showing through, then yes you will have to take the keel to bare metal and start again.
Address any "spots" that are most likely chips, by taking to bare metal and follow the above advice prime.

The present coating is most likly an Epoxy. DO NOT paint this coating without first giving the entire surface a good sand to key it. Use an 80grit, don't sand it tooo hard, just abrade the surface to create a "key. Then you need to apply another coat of Epoxy or the product Mike has suggested. That coat of epoxy or what ever is over any primers and fillers and fairers and so on. It is what you anti-foul will adhere to. If you do not abbrade the surface, your new coats will fall off.

Caution, if any old anti-foul is still on the surface, then be very careful about sanding or grinding dry. Make sure you are well protected with a good dust mask and overalls with a hood. Wash hands.

[EngNate]

Tried that on some engine parts, that's some tough stuff. Stir patiently, never shake or the bubbles will never come out of it! Use plastic film when resealing the can, or you'll never get it open again.