DaySailer.org Forum

I have seen this covered in bits and pieces in other threads.

I'd like to move the jib cleats to the CB trunk using harken 365 carbo blocks. They recommend attaching them with #10 screws. They don't specify machine or wood, but I would assume machine since they need to go through the Cam Cleat itself.

So I see it as I'm left with 2 options through Bolt or drill and tap.

Through bolting is stronger but how can I get up in the trunk w/o removing the CB? ( the boat is already careened in the backyard)

Drill and tap- I've never done it before I would assume use a standard drill and tap kit for 10X24 and drill down 3/8 -1/2 inch and tap it add a little 5200 and screw in the cleat?

My concern is strength and how to tap fiberglass, I'd rather put the work in now rather than deal with a major repair later

You can use #10 stainless steel sheet metal screws, as sold by marine supply companies. This is pretty much the standard of the industry on fiberglass boats. One of my cam cleats on top of my centerboard trunk loosened up after 35 years of use, so I waxed the screws and put a dab of epoxy down in the hull and they've been holding fine for 2 years now.

The trick with putting sheet metal screws in fiberglass is that the fiberglass has no give, or very little. So, you need to size the pilot hole for the screw somewhat looser than you would for wood or you'll break your screws off putting them in. Countersink the hole to keep the gelcoat from popping off before you drive the screw. I sometimes make a tap for sheet metal screws by grinding the threads on an extra screw to make self tapping threads.

An alternative is to create a bracket which can then be attached by through-bolting from side to side (instead of down). These bolts would go directly below the inside edge of the top part of the fiberglass of the CB, so they barely intrude into the CB trunk. The cleat itself is then bolted to the bracket.

Some people have made brackets from wood. I've had mine machined in SS at a local shop. The PO had made one from aluminum U channel (or it may have come with the boat originally).

Here's a picture of my setup.



In my case, the top of the CB trunk has an ugly glob of resin, that is hidden by the bracket. That makes me think, the boat originally came with a bracket of some kind. So for me, the bracket serves the additional purpose of hiding that.

My setup is similar to GreenLakes, only mine's a big chunk of wood (not sure what kind, actually)