Stewart-
I helped another owner do this a few years back on a J/30. A few comments/thoughts that might help...
For templates, use something ridgid. We used templates that had been CNC cut out of 3/16" aluminum. Very slick. Very accurate.
Once we had the centerline, and stations identified (a laser helps here), we "blocked" each template into place on one side of the keel (then repeated the following process on the other). If material removal was required, we did so first. If not, we used small blocks, hot-glued to the keel, to support the template in place. Also glued the template to the blocks. Where there was a gap, we filled with a fillet of epoxy+dense filler to create the new "high point" or guide for true dimension at that station. Cool trick: color this epoxy with a red pigment additive so that it's easier to see later when filling out low points (or sanding with a long board) with standard epoxy+filler.
Do this for each station. Once they cure, you should be able to use these new ridges - that represent the proper shape - as guides to drag new filler into place later.
We used a long straitedge to effectively take the filler required and "drag" perpendicular to the station guides. This allowed us to effectively float the filler evenly between each station to ensure precision and reduce excessive, random shaping later.
I hope this is making sense - wish I had pics to post.
Other thoughts...
- Where there's exposed lead, sand it and quickly apply a skim coat of resin so that the metal does not oxidize.
- Once you have your shaped/faired keel, barrier coat it well with Interlux product.
- Like anything, this project is 98% prep.
- We found that the keel was quite asymetrical (i.e. on the port side, it was very close. On the starboard side, the shape was almost as if the trailing thinkness was near the front and the front thickness was towards the back). Not surprisingly, we found that on the water impact was more predictable, even performance tack to tack afterwards.
That's about all I can think of for now. Post any questions you have and I'm happy to help answer them. However, I'm sure many folks on this board have much more experience at this than I do.
Cheers,
- JBro
