Rebedding the genoa tracks

After 20 years, particularly if you race a lot, sealants start to fail, allowing water to get into the core. So, for the last few years, I've been slowly going around the boat, rebedding all the hardware. Collectively, it's a big project, but spread over many years, it has not been very burdensome. It's certainly a lot easier than recoring!

This year's project was rebedding the genoa tracks. It's not a hard project, but there are a hell of a lot of bolts holding these things down — 78 of them, to be precise — so it can get pretty tedious. The entire project took four days for two of us, but this includes a wasted day trying to install a backing plate. More later.

Materials used


Remove the trim down below that covers the genoa track nuts. You may also have to remove some of the surrounding trim to gain access to the nuts.

Get a buddy to help you with removing the track. One person will need to be on the outside with the screwdriver, the other inside undoing the nuts.

While the track looks curved, once untensioned, it is actually straight. The bad news is that bending moment means the track pushes hard against all those bolts, making them hard to remove. Some judicious tapping from down below using a plastic or rubber mallet, while the guy above turns with the screwdriver, will help persuade them to come out. It also helps to physically bend the track to lesson the sideways pressure on the bolts.

So, now the good news: that same pressure also makes it easy to break the bond of the sealant. You may have to slip a putty knife under the track to persuade it to release, but it should come off relatively easily. Be careful and lift gently — you don't want to nick anything. Lay the track aside and get ready to spend the next 6 hours cleaning everything.

I mostly used plastic razors to remove the old caulk. Occasionally, a steel razor blade was useful, but be careful not to knick the gelcoat.

By pulling with one hand, and sawing away at the other, you can get the caulk to release in long strips. I didn't have an extra hand to take the picture, so you'll have to use your imagination.

Endless cleaning! The holes were particularly hard to clean. We ended up tearing green Scotch pads into long skinny strips, then using them like dental floss.

I found the products Release and Re-Mov-It were useful for removing the old caulk.

Be sure to scour the deck under the track.

Ream out the holes using a 5/16" drill bit.

Then countersink the holes.

Finally, ream out  the core between the top and bottom fiberglass skins. I use a bent piece of 1/8" stainless steel rod, but some prefer to use an old Allen wrench. Whatever you use, it should ream out about 1/4" beyond the hole.

In preparation for injecting epoxy into the holes, tape the bottoms with some duct tape.

Now, using a syringe, fill the holes with thickened epoxy to just below the surface. Wait 3 or 4 minutes for the bubbles to rise to the surface.

Using a cable tie or some other tool, poke the epoxy a bit, encouraging any bubbles to rise to the surface and pop. When you are done, fill the hole to the top.

After the epoxy has hardened, redrill all the holes. I found this portable drill guide to be very useful to not only get the holes straight, but also to prevent the drill bit from drifting on the uneven epoxy surface.

Time to get the track ready. Lay down a strip of butyl tape down the middle. I found the nominal 3/8" width of the Bed-It tape to be just perfect for this.

Using an awl or other sharp tool, make holes for each of the bolts.

Put a thin layer of butyl tape under the heads of each bolt.

Push the bolts through, then put another thin layer of tape where the bolts come through the track. This will fill the countersinked holes in the deck.

The track, ready to install.

One final wipe of acetone. As an experiment, we masked one of the tracks, thinking it would make it easier to remove the excess butyl tape. It didn't. Don't bother.

Press the track into place. Because the straight track must be bent into position, it's essential to have at least two people to do this. Start at one end and put the first few bolts into the holes just a few millimeters. Then work your way down the track, bending as you go. Wait until the very end before seating the bolts the rest of the way with a rubber hammer.

I torqued all the bolts down to about 15 foot-pounds, then waited overnight and did it again. It takes a while for the butyl tape to "flow" and get out of the way, so it's essential to do this in a two step process. Warmer weather can speed things up.

When you're done, clean up the tops of the bolts by using a little wad of butyl tape and "dabbing" at them. This can be amazingly effective. Remove the caulk on the sides of the tracks by using a small screwdriver. Again, warmer weather helps for this.

I originally wanted to add a G10 backing plate. Unfortunately, the extra thickness of the plate would require a longer bolt. The original bolts are 2" long. A 1/4" backing plate would require a 2¼" bolt. Unfortunately, I couldn't find any in 316 stainless, and a 2½" bolt would be too long and require new trim covers to be built. So, I settled for doubling up the fender washers: 2 per bolt.

While a backing plate would be nice, you still end up with something a lot stronger than the original because of the epoxy "donut".