Windlass replacement

[awsmits]

On my “new to me” boat, a 1989 Sea Ray 440, I am replacing the windlass, which has a much larger footprint than the one I plan to install new. Meaning, I’ll likely need to cover the old windlass holes with some material, and drill new mounting holes for my new windlass. What should that material be, and how should I best attach it to the existing fiberglass deck? Thanks.

[pesarsten]

I would suggest using either HDPE 1/2 sheet between the new windlass and the deck or a piece of G10 Big enough to cover the old holes.

How Much of a crown does the deck have where the windlass mounts. A piece of teak an inch thick could be shaped with a plane to match the deck crown.

[awsmits]

Thanks for the material recommendation. Not much if any crown to the deck. Would you bolt it down, use adhesive, or both?

[chris mac]

I had this same problem when we replaced ours. The new unit also sat lower so I also had to raise it.
Starboard worked very well! Well over 100 nights on anchor since, and no issues

Edit,
We just through bolted. I thought about adhesive, but didn't feel it would add any strength in our situation

[pesarsten]

Without question bolt it down. The windlass will usually include the bolts for securing to the deck. I also suggest adding a layer of 3/4 marine ply that has been wrapped in glass and coated with epoxy before securing it under the deck where the windlass will mount. I used cabosil to thicken the epoxy to adhere to the underside ofthedeck.Call it a backing plate.

[Fortytwo]

No marine ply... all G10. If you have to redo the deck with G10... do it.

Adhesive is not for strength when you through bolt, it’s for anti water egress.

[chowdan]

Adhesive is for strength, that's the purpose of an adhesive!

Sealant is for anti water egress.

Don't use plywood, DO NOT use HDPE regardless of what anyone says, that stuff has no use as a backing plate or topping plate. It compresses easily and turns to a goo under compressive loads and allows things to shift.

Do use G10 or just grind the holes if they are large and layup glass to fair it smooth and re-drill your holes

Originally Posted by Fortytwo

No marine ply... all G10. If you have to redo the deck with G10... do it.

Adhesive is not for strength when you through bolt, it’s for anti water egress.

Here's the system I built to install a windlass not on the anchor locker lid. Solid GRP with 1708, hand laid at a 55% resin to glass ratio.

[Fortytwo]

You are correct in the correct application, but, what I meant is don’t depend on adhesive for backing.

[chrisr]

we did exactly this recently. covered the hole with 10mm carbon fibre sheet through bolted to the deck, and then cut the new access.

strong as can be, light, easy to work...and looks cool too.

cheers,

[motion30]

I had this exact situation I used a half inch aluminum plate on the outside and a quarter inch aluminum plate on the inside. Maybe Overkill but the chance of failure would be catastrophic

[steve77]

We replaced our windlass a few weeks ago. I used one inch thick teak on deck as a spacer and one-half inch thick G10 under the deck as a backing plate. I am not a fan of HDPE for the spacer for the reasons Chowdan has already given.

When selecting your backing plate material, remember that it will get wet from water coming down the hawsepipe. G10 is perfect for this application.

As far as whether to bolt it down or use adhesive - check your installation instructions. I will be shocked if it says to do anything other than through bolt the windlass with sealant to prevent leaks. Our Muir windlass had the bolts in the box.

Best of luck with your project.

Steve