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Dorade Base-plate Repair
Cathy and I removed our dorade boxes to refinish them. We discovered that the plywood base plates that they attach to were delaminating. They must not have been a marine grade plywood or at least not a good one. It did not appear to be an easy task to remove them and replace them with new ones. Our solution was to repair the old ones. First, we glued any of the delaminations that we could get at. Be sure to use a waterproof glue. We used Elmers Tite-Bond. To hold the delaminated places while the glue dried, we used bronze ring nails. Make certain that they are not longer than the plywood is thick! We got ours at Ace hardware. West Marine is another source. The rings give a better bite for the nail in the plywood. Once the glue was dry, we put the bronze nails in at about a one inch pattern. It looked kind of silly but should help keep the plywood together. If there were serious delamination or evidence of rot, I'd use "Git-Rot" in those areas at this point. Git-Rot is a two part mix resin like liquid that you mix up and squirt into holes that you have drilled into the rotted area. The Git-Rot flows into the rotted wood and hardens, making it strong again. You keep putting it in the holes until they stay full. We did not have to do this. The next step is to seal the wood against moisture and make it look a little better. Make sure the wood is dry and well sanded and clean before the next step. Mask the cabin top around the edges of the base plate with 3M blue masking tape. You can peel this off as soon as the resin kicks and stops running. We use West System epoxy. If you have some large voids in the plywood especially around the edges, get one of the filler mixes West sells like 403 to thicken the epoxy to a peanut butter consistency and force that in the voids and let it harden a bit before the next step. This stuff is like dust when you take it out of it's can so a paper dust mask would be good here along with the latex disposable gloves to make you look like an expert! The gloves sure solve the problem of cleaning up your hands later. Don't forget to mix the resin and hardener for about a minute before adding the filler to thicken it. Just keep adding the filler until you get a peanut butter consistency that won't run. Once the voids are full and you have sanded off any protruding filler you are ready to enclose the plywood in a resin cocoon to keep moisture out. Mix up some resin (stir about a minute to ensure good mixing) with the 205 hardener and coat the top and sides. We used disposable bristle brushes for this. The 205 hardener kicks pretty quickly, especially in hot weather, so your working time is limited with each batch. But it sets up pretty quickly so it runs less on the vertical edges. You can user the 206 hardener if you want more time. Be aware that when the mix kicks, the remainder in the cup will get HOT if there is enough volume that it can't get rid of the heat fast enough. Can be pretty impressive but fun to watch! We use clear plastic disposable drinking cups to mix the resin in. They will crumple with the heat and if there is enough in the cup, it will smoke and you must be careful where you set it. We just put some water in it to cool it down and set it on the concrete dock until it is disposed of. We used three coats before the edges were sealed. We did all three in one day so we didn't have to sand between coats or deal with the "blush" that develops after about 24 hours. We left a small strip of about 1/16 of an inch of the cabin top exposed between the tape and the base plate to let the epoxy seal the bottom of the base plate against water getting underneath. You could use a sealer but we used the epoxy since we were right there with it. Don't forget to do the inside of the cutout that carries the water out. The last step was to paint it with white paint to make it look like new. Be certain to sand lightly to give the paint a good surface to adhere to. We used slightly larger stainless screws when we put the dorade boxes back on to make sure they got a good bite. This may not be how a boat yard would do it but it workedfor us and should last for years. Return to Baba Maintenance Tips
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