Bedding winch on teak
- Thread starter malyea
- Start date
I'm going to be replacing mine when it gets above ~0~ and was just planning on using clear silicone around each screw hole where it goes through the teak.
Think about use something like Plasteak for the base material. This will prevent you from having maintenance issues in the future.
I like the butyl tape. Much less messy than 4200 or silicone and won't adere so strongly that you can't get the winch off later.
Winch backing plates
For under the winch I might go with something like butyl tape-- it's one of the few applications in which it has merit. Think about the properties of butyl tape and then about what winches' loads are. These are technically incompatible.
I have made nice rubber gaskets for these in the past as well. Tension on the bolts compresses it to the point of holding back water.
The winch's load, mounted on the deck, is all in shear-- not pulling up, but ripping sideways, horizontally. Therefore I would not mess around with minor materials like Starboard for a backing plate. It won't adhere to the deck structure-- it's only good for tensile (pulling up) loads. Your winches are 40s; they're handling more of a load than mere washers should be expected to support. I would use the thickest piece of material that won't delaminate: prefabricated fiberglass board, like you can get from McMaster-Carr, G-10 (ditto), or even solid-core plywood well-saturated in epoxy (to keep it from crushing or delaminating). This should be bonded well to the underside of the deck-- I would use 5200 because its enormous strength resists shear loads (as well as tensile) very well.
When I install these, I drive one or two sheet-metal screws into the plate from the bottom, punching right out through the fiberglass deck (under where the hardware will go-- if you're tidy you'll locate these screws where the hardware's holes will be. Let the 5200 cure thoroughly before removing these screws, position the part and mark and drill holes down through the top. You want the plate to be well bonded to the deck, like a part of it. (Fill the screw holes with a little 5200-- you won't see it under the hardware.)
The goal, with shear loads, is to present as thick a strata against the shanks of the bolts so they have something to lean against. Mere cored deck may survive for a while, especially if you've overbored the holes, filled with epoxy and redrilled; but it's really not the best agent for shear loads. You don't want foam and thin fiberglass skin holding back machine screws in shear.
I apply most of my backing plates like this-- stanchion bases, mooring cleats, winches, rode chocks, genoa tracks, anything that can be subjected to a shear or rocking load. In the case of cleats and stanchion bases, these oversized backing plates, well bonded, make good anchor points for interior trim such as facia boards.
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For under the winch I might go with something like butyl tape-- it's one of the few applications in which it has merit. Think about the properties of butyl tape and then about what winches' loads are. These are technically incompatible.
I have made nice rubber gaskets for these in the past as well. Tension on the bolts compresses it to the point of holding back water.
The winch's load, mounted on the deck, is all in shear-- not pulling up, but ripping sideways, horizontally. Therefore I would not mess around with minor materials like Starboard for a backing plate. It won't adhere to the deck structure-- it's only good for tensile (pulling up) loads. Your winches are 40s; they're handling more of a load than mere washers should be expected to support. I would use the thickest piece of material that won't delaminate: prefabricated fiberglass board, like you can get from McMaster-Carr, G-10 (ditto), or even solid-core plywood well-saturated in epoxy (to keep it from crushing or delaminating). This should be bonded well to the underside of the deck-- I would use 5200 because its enormous strength resists shear loads (as well as tensile) very well.
When I install these, I drive one or two sheet-metal screws into the plate from the bottom, punching right out through the fiberglass deck (under where the hardware will go-- if you're tidy you'll locate these screws where the hardware's holes will be. Let the 5200 cure thoroughly before removing these screws, position the part and mark and drill holes down through the top. You want the plate to be well bonded to the deck, like a part of it. (Fill the screw holes with a little 5200-- you won't see it under the hardware.)
The goal, with shear loads, is to present as thick a strata against the shanks of the bolts so they have something to lean against. Mere cored deck may survive for a while, especially if you've overbored the holes, filled with epoxy and redrilled; but it's really not the best agent for shear loads. You don't want foam and thin fiberglass skin holding back machine screws in shear.
I apply most of my backing plates like this-- stanchion bases, mooring cleats, winches, rode chocks, genoa tracks, anything that can be subjected to a shear or rocking load. In the case of cleats and stanchion bases, these oversized backing plates, well bonded, make good anchor points for interior trim such as facia boards.
* * *