J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Keel Fairing

I decided to fair my keel this spring as it was prety rough. We took off old paint and filler down to the lead (not much there). I started building templates from the class association specifications and the first two I have built (station #1 and #2 both say I need to build up the leading edge by 1/2" to 3/4" and it appears it will be more down lower as the leading edge of the keel bends back a little between station #1 and #2. Has anyone done this and found that the leading edge shape is off by that much? Any suggestions?

Well it's work in progress on Rhapsody right now. This was done about 10 years ago by the previous owner with some subsequent keel repair for flaking glass, so it's not too far off. I did find the port side had more to be sanded down and a low spot on the stbd side needing filling. The leading edge wasn't too bad. Here are pictures taken 11 April 2007. I hope to finish on 13 April and start the bottom stripping for complete repaint with new barrier coat & VC Offshore.







Bill
Rhapsody #348

[This message has been edited by whk (edited 04-19-2007).]

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

One more thing...

On your templates, be sure to mark them at 10%, 20%, 30%, etc. from leading edge to trailing edge. When fairing, repeatedly transfer these marks to the keel with a Sharpie pen.

The reason is that you'll want to lay a batten or flexible straitedge across these points (i.e. Stations 1-5 at the 10% mark, same at the 20% mark, etc. - will effectively look like holding it from top to bottom) to ensure there are no "scallops" or low points between the stations at each fore/aft point as you fair to get to the new stations.

To help find the low spots, once the straightedge is in place, hold a shoplight up against the keep on one side of the straitedge... look towards the light from the other side of the straitedge. You'll quickly see where the low points are.

Hope this makes sense. Trying to explain this stuff in text is not the easiest!

- JBro

[This message has been edited by JBro (edited 04-13-2007).]

[This message has been edited by JBro (edited 04-13-2007).]

Thanks for the great tips and pictures. This is a big help