Waterline?

[ebsail]

Yes - Making the holes oversized and filling them with epoxy and then redrilling is the correct method. So are the backing plates. I strongly suggest drilling the final bracket holes, one at a time, and inserting a bolt in the first hole before before drilling the second and so on. We found it difficult to hold the bracket in position due to its weight while marking the holes.
On my boat, we discovered that some of the old transom core was rotten while we were drilling the holes. So in additon to oversized holes and epoxy, we drilled rows of 3/8" holes into the transom about 2" apart from the inside, up to, but not through the exterior skin. Then we inserted short pieces 3/8" hardwood dowel , dipped in epoxy (you only have to dip the nose of the dowel, enough epoxy will scrape off while you're inserting to cement to the interior skin) and gently tapped it home. After curing for a day or so, we cut off the interior excess with a sharp chisel and a hammer. Result was a very stiff and, hopefuly strong transom, we think. Anyway we are showing no flex at all.

 

[Roy 845]

Good advice Brian. I'm prioritizing my repairs so when it comes time to put her in the water, April, I will have the absolutely necessary items complete and items on the B list can be done at the Marina. My goal is to have all the surface damage repaired and the bottom painted first then I'll get the electrical done. I can use unfinished repairs such as resealing all the deck penetrations etc on the Boat as an excuse to leave the house instead of mowing the lawn during the nice weather. I'm fortunate enough to have room in our repair shop at work that I can put her in Friday nights and do repairs on the weekend as long as I have her out before Monday morning. Yesterday afternoon I went to work on her after doing some maintenance on my Ford so by 4pm I was starting to do some hull repairs when my phone rang and I was summoned home to repair a broken shower faucet that was spraying. Today I was on my way to the shop to get going on her again and my middle daughter called that her car broke down, by 5pm I was done with that repair and all I could on the Boat was cover her back up and park her back outside.

 

[Roy 845]

Yes I found there is rot inside the Transom and I'm going to cut away a small section on the inside to see how easy or hard it will be. If it goes well maybe I'll get a larger piece of G-10 and epoxy it in there where the rotten wood was then use the 12" square piece I have now as a doubler. As I move my engine mount lower I also need to go more towards the centerline so I'm going to hang my Rudder temporarily to make sure they will not interfere with each other.

 

[Ritdog]

You have a plywood transom board inside? Oday 25 have a 30" "square" piece of 3/4" ply wood to stiffen the transom to prevent oil canning. It's usually poly'd down and usually rotten, and always a bitch to grind out. I would check that. The 12" square plate you mention doesn't seem quite big enough.
If you have a rotten plate in there you should take it out and replace it. I used three layers of 1/4" ply poly'd in, as the transom is curved, with a layer of mat between the layers ( heavy layer of deck putty on the wetted-out glass first!)
I would also check the king plank. I set 1.5" holes in all the layers first where there were through holes , epoxied the holes, layered it all up, then re-drilled the bolt holes for the mount and gudgeons.