Centre cleat installation

[N44rag]

Hi all

Is anyone able to give me some guidance on how to go about installing a centre cleat on my B31, year 2000 model?

The deck has the raised moulding for the cleats and I have sourced the new ones from SVB24.

I have read on the forum that the area is prepared for installation with a backing plate, but I’m not clear whether I have to simply drill through the deck and through the plate fitting a back nut and washer, or try and tap a thread into the backplate.

Also I’ve seen elsewhere that some people drill a bigger hole than the bolt in the deck, fill the area with epoxy, then re-drill through again.

Any guidance would be a great help.

[SYJetzt]

First you have to find access to the inner side of the deck where the cleat is mounted, usually hidden  in lockers . Once found, it is straight forward. If you have a backing plate already laminated to the deck, simply drill holes and fix the cleat with back nuts and washer.

[Yngmar]

The whole point of a backing plate laminated into the deck is that you do not need access from the inside. You drill a hole, cut a thread into the thick aluminium backing plate and insert the bolts into that. That's how the winches and rope clutches were mounted on our 40 Ocean (even though there was access from the inside). The mooring cleats had proper backing plates on the inside and access slots in the furniture for them. No idea what the B31 from 2000 has.

[N44rag]

Thanks both for your replies.

It seems both options (bolt through or thread) are possible as long as the backing plate has been moulded into the deck.

I will take a look behind the furniture and go from there.

I assume a straightforward Sikaflex seal is all that is needed between the cleat and deck without the need for any resin work?

[symphony2]

no need to dismantle the interior if the plate is moulded it. It almost certainly will be as the mid cleats were optional and the deck moulding common. Check with something like this screwfix.com/p/magnusson-3-in-1-material-detector/3062x Butyl tapes is commonly used for sealing although you can use Sikaflex if that is what you have.

[N44rag]

Ok thanks, I’ve just checked the holes in the cleat and it seems an M8 bolt will do the trick, just need to establish the length now.

Always nerve racking drilling holes in boats!

[SYJetzt]

Always nerve racking drilling holes in boats!

You're not going to drill them below the waterline, are you?

[N44rag]

Started with fixing two pad eyes today while waiting for the delivery of the correct size tapping drill for fixing the midship cleats.

Pleased to say that I found the aluminium plates that are moulded into the deck under the pad eyes as well and was able to tap a 6mm thread into those for the machine bolts. I would not have been able to get a back nut on those bolts without stripping out the joinery cupboards, so very pleased to have found the plates.