Thread: The 1985 Skeeter SF-175 will need a transom repair

Since my previous work cured by yesterday afternoon, I started cutting out some cardboard pieces to use to measure out a rough area of the transom between the inner and outer skins. When I finished and put marks onto the first round of transom templates, I realized that I had some really hard wood still in the transom in the upper corners. I went ahead and traced out the first guess of the shape to more cardboard so that I can start fitting to the transom to confirm my coosa board allocation.



After some work with the cardboard, review with a boroscope to understand interference areas, and redo in one case, I understand the basic shape and how it relates to a big piece of coosa from Rojo's scraps as well as another piece that I ended up ordering online. The good news is that it helps confirm square and volumetric area so that I can see how many more gallons of West System 105 Epoxy Resin, 209 Extra Slow Hardener, and 406 Colloidal Silica that I need to order.



I'm probably going to be doing more sanding inside the transom skins the rest of the afternoon to get the cavity closer the the coast's 1.5" thickness plus 2 pieces of 1708 fiberglass mat that I'm installing. After that, I'll cut another cardboard template (or more) with the purpose of figuring out the best way to work with the opening before I even think about touching the coosa board and fiberglass.

While I have the area that is accessible sanded with 24-grit sanding discs, deep in the cavity needed a little redneck engineering to smooth out and really get the last bit of wood sanded out of the fiberglass to open the cavity enough without having to reduce the new core's thickness and make room for 2 layers of 1708 biaxial fiberglass as well as let the new assembly stick to the actual fiberglass and not wood fragments. Just for what I had around the house in a scrap pile, I found a piece of wood fence plank that I was able to staple sandpaper to it and sand away.



I still have a good bit of sanding to do deeper into the cavities, although the areas near the opening are improving.

Sometimes it's bit by bit, however you are gettin' 'er done, and that's what is important. This type work, if done right won't get done overnight. It's coming along nicely and something you'll be proud of.

I felt like you were a detail guy like me, now I know it.

Yes, as an engineer, I’m into the details; however, I do have my moments when they irk me—it least there are tolerance ranges. This sanding was going to be required, regardless, and I can still see some wood fibers without the aid of a boroscope. The little bit of wood stock to the fiberglass was the only dry wood in that transom. It would be a different story if all that was left was the old fiberglass skin and the only material to thin was the coosa.

Originally Posted by jjue1979

Yes, as an engineer, I’m into the details; however, I do have my moments when they irk me—it least there are tolerance ranges. This sanding was going to be required, regardless, and I can still see some wood fibers without the aid of a boroscope. The little bit of wood stock to the fiberglass was the only dry wood in that transom. It would be a different story if all that was left was the old fiberglass skin and the only material to thin was the coosa.

Now that you are into the transom well what is your opinion of the guys who use a chainsaw to dig out rotten wood in a transom from the top, mix a catalyzed transom repair, pourable, polyester based not epoxy, dump that stuff in, let it cure, then hang twin 300's off the back and run 100 miles offshore with it?

Originally Posted by Rojo

Now that you are into the transom well what is your opinion of the guys who use a chainsaw to dig out rotten wood in a transom from the top, mix a catalyzed transom repair, pourable, polyester based not epoxy, dump that stuff in, let it cure, then hang twin 300's off the back and run 100 miles offshore with it?

Seeing the condition of my transom wood, I doubt that they got out all of the core wood, especially since none of them show a sanding process to get a good bond. For all that we know, they still have wet wood hanging on for dear life before they start pouring--at least the wood that I'm sanding on is dry and will still make a decent bond if I miss a spot. Also, one of the reasons that I ultimately went this route was for a little weight reduction for future upgrades--all of the poured transom kits are heavier than going back to marine-grade plywood, and Coosa BW26 is lighter than marine-grade plywood. My boat needed a good digging and fiberglass work, and if I had gone the pourable route, I'd still have rotten knee braces, a rotten transverse brace, and probably a lot of chemical mess in the bilge storage area seeing all the holes that I didn't make (and I did make some during the digging). Some of them may have been to let the wood "breathe," although some of them were also from sloppy work.

I decided to see how well a squirt bottle of Unhesive actually works to clean up some 5200 that I had sealing off my transducer block. Per the instructions, I spray, let sit for 20 minutes, and then I should peel the adhesive off. After some experimentation, I ended up soaking in a little, spray a little more, and then use a blade to scrap it off.

->

While waiting, I decided to play around with a new cutout template to see how many pieces of transom core are required. I tried a different pattern of 4 pieces, which I could tell wasn't going to work, although I did see that I could actually do this in 3 pieces, as long as the center isn't more than 24" wide.



Since my wife is working, I've had to work on chores that allowed me to work in and out of the house some, since the kids will just play on electronic devices if I don't keep an eye on them. When she gets home from work later this afternoon, maybe I'll get into the mood to put on my PPE and do some sanding uninterrupted.