Hey Jibes,
It's hard to go wrong following the West Systems methods. You may go broke but no one at the marina will laugh at you.
I find that most products sold in the Marine market are a bit better suited for such purpose than the ones intended for general use. There are many exceptions to this and by and large you are paying for and expensive multi level distribution system and a very expensive retail outlet. Most of the time I'm happy to pay the higher price since no one at walmart will help me select the proper anchor for my boat and cruising grounds. But when it comes to the paint field I find the stories hard to swallow.
What you have heard:
Bondo absorbs water. Yes of course it does. ALL paint and composites absorb water. Even the West System.
Bondo is likely polyester based product with talc as a filler. Talc is not the culprit causing water absorption. Read below. Talc absorbs the least amount of water. Vinylesters are better than polyesters to retard (not eliminate water absorption.) Are they worth 10 times more?? I say no.
http://kreysler.com/information/spe...development_of_low_moisture_absorbing_smc.pdf
Bondo CAN NOT be used on wooden boats. I sure agree with that but we will see in a year or two how it does on a primed cast iron keel.
I do not feel I have anything to loose. It took me and hour to apply and fair the filler. I could care less if it pops out next week.
As for the iron keel: Jeanneau designed the boat. Later, it might have been O'day who changed the design to a lead keel with a deep bilge. I believe they also made a centerboard /shoal draft boat at that time. I have not seen one of them but I have a drawing of it in my owners manual. I have a fixed shoal draft. I have not seen a lead version of this.
I blasted the bottom with black slag from Mernards at $6.00 per bag after the soda @ many times that did not work. The black slag took it down to the iron. I primed it the same day. The Black slag took everything off the hull except for the Coal tar epoxy that someone applied when it was new. The boat has never had a blister despite being in the Caribbean most of it's life. The west system can not match this record of nearly 30 years without a blister.
So what should I put on for bottom paint? I'll have it in the water all next summer but from then on it will see water only a few weeks a year.