Here’s what I found. Hope it helps.
I decided to remove and rebed the tracks on the side decks of my ‘79 25+. The bolts appear to have been threaded into an aluminum plate about 1/4” thick, embedded in the sandwich layup. I was only able to remove about 2/3 of the 22 bolts holding the track down in each side. The rest of the bolts twisted off between the aluminum plate and the bolt head. I assume dissimilar metal corrosion. I was not able to drill out the stuck bolts, so I drilled new 1/4” holes offset a couple of inches rearward from the originals.
I found no wood in the core, so I did not drill-fill-redrill. I had to cut away sections of frp liner to get at the bottom of all the holes from the inside. I’ll figure out a repair and cosmetics for that later. The new setup is traditional through bolted, with all of the nuts exposed so if I do run into leaks again, it should be quick and easy to identify and remedy. I’m using polysulfide bedding for the first time. It’s messy and sticky. The first track required some cleanup. I found a procedure for the second track that is much cleaner but requires some prep.
The embedded aluminum plate was a surprise to me but must be old news to many of you. I decided to share in case someone else decides to take this on.
I decided to remove and rebed the tracks on the side decks of my ‘79 25+. The bolts appear to have been threaded into an aluminum plate about 1/4” thick, embedded in the sandwich layup. I was only able to remove about 2/3 of the 22 bolts holding the track down in each side. The rest of the bolts twisted off between the aluminum plate and the bolt head. I assume dissimilar metal corrosion. I was not able to drill out the stuck bolts, so I drilled new 1/4” holes offset a couple of inches rearward from the originals.
I found no wood in the core, so I did not drill-fill-redrill. I had to cut away sections of frp liner to get at the bottom of all the holes from the inside. I’ll figure out a repair and cosmetics for that later. The new setup is traditional through bolted, with all of the nuts exposed so if I do run into leaks again, it should be quick and easy to identify and remedy. I’m using polysulfide bedding for the first time. It’s messy and sticky. The first track required some cleanup. I found a procedure for the second track that is much cleaner but requires some prep.
The embedded aluminum plate was a surprise to me but must be old news to many of you. I decided to share in case someone else decides to take this on.