Adding midship cleats - to pot or not?

Sep 1, 2019
ComPac Sun Cat On the Delaware
My Com Pac Sun Cat came with three cleats (a single bow and two stern) - I'd like to add two midship cleats to make tying up with springlines easier. I've done some searching on the web and the overwhelming consensus is to use backing plates rather than washers.

I've been in touch with Com Pac (an aside: they are great to deal with and always respond quickly to inquiries) who tell me that they don believe a backing plate is necessary. The reasoning is that two outboard bolts will go through the deck and the hull flange, where it is pretty thick and that they think the deck is strong enough for the loads from the two inboard bolts. The Sun Cat owners manual states the Com Pac uses a foam core (a "micro-balloon resin mixture") that the factory claims is far more resistant to water damage than balsa or ply.

I think that backing plates are cheap insurance and plan on using them even if the factory doesn't. Using butyl tape around the fasteners is a given, and I initially planned on using silcone sealant to complete the installation. This would be in line with what the factory does.

From what I can determine, potting the holes with epoxy falls into the recommended but not essential category. It requires a considerable amount of extra work, along with the purchase of a Dremel tool and some tips. Is the added effort worthwhile?
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Feb 8, 2014
Columbia 36 Muskegon
I'd do it. Not that much more work but definitely more time. Need a day or at least several hours for the epoxy to kick before you can redrill the holes.
Jan 19, 2010
Hunter 26 Charleston
:plus: on no silicone...

Also.... my understanding of prefilling holes with epoxy and redrilling is to protect the wood core from rot. Since you don't have a wood core... why bother?
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Likes: Brian S
Aug 12, 2018
Hunter 26 Carter Lake, Colorado
Another reason to epoxy/drill is to provide better compression resistance.

And even foam cores should generally be protected from water intrusion. That water could end up who knows where.

Mr Fox

Aug 31, 2017
Marshall 22 Portland, ME
Anytime you drill through a cored deck you should seal the exposed core with epoxy; crucial for wood, still needed for foam. The manual states the foam is more resistant than wood to water damage, it doesn’t say impervious to. Repairing saturated core is very very expensive, spend the little extra time to do the job correctly the first time. An old Allen wrench or bent nail in a drill works great, no dremel needed.

Butyl tape is awesome for sealing deck hardware, easy as pie to work with. Polysulfide is an excellent choice as well (life caulk for instance). While an excellent (sometimes only) choice for certain applications, marine (never household) silicone is tricky on deck hardware- fast cure times can make it messy and it interferes with paint and varnish.

100% right call on the backing plate, not even a question.
Dec 30, 2020
com pac eclipse sunset, louisiana
What is the opinion about midship cleats? New guy waiting on my eclipse.
Should I have it added?
Feb 8, 2014
Columbia 36 Muskegon
Maybe the most important cleats on the boat. Not so much for securing to the dock, but for maneuvering to or from the dock. When approaching the dock, put line ashore from the mid cleat. Then power ahead at minimum speed on that line with the rudder turned away from the dock, the boat will snug up to the dock and stay as long as the engine stays running. (Hang a couple fenders on that side first.) Gives you all time in the world to make up the rest of the lines. No yelling, running around, or Chinese fire drills. Do the same thing when leaving. And as stated above spring lines are much easier led to mid cleats.
I'm a commercial Captain, running passenger vessels in the 65 foot range. We couldn't do what we do without mid cleats. We typically will come up to the dock, discharge passengers, load another bunch, and depart, all with only making up that one line. We only make up the bow and stern lines when we're done for the day or will be tied up for an extended period.
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