Transom Rot

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Transom Rot

Postby nickc » Fri Jan 06, 2023 2:35 pm

https://photos.app.goo.gl/HojLKRxQ7Dtko87b8

The above link is a video of what I am describing. I went to roll my DSII out of the garage to pressure wash it before completing some gelcoat repairs and I noticed some water dripping out of a crack near the top of the transom. I drilled a few inspection holes and sure enough the wood inside is wet and mushy, but the transom doesn’t feel week or soft from the outside. Is this something I need to address right now or is this something I can leave for the moment and deal with next season? Or, is this something that means the boat is dead? I really hope that’s not the case.
Thanks,
Nick
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Re: Transom Rot

Postby Vanalien » Wed Feb 01, 2023 12:41 pm

I discovered the same condition in my DS2 two or three years ago when mounting a swim ladder. I had capsized the boat at the end of my first season owning the boat, 2017, and didn’t get the bilge pumped out until a week or two later, and the bilge was completely filled. I don’t know if that is when the transom got waterlogged, or if it might have been from before I owned it, but the wood near the top of the transom was wet enough to squeeze out drops of water from the sawdust emerging from the 1/4 inch holes I was drilling at least 2 years later.

I don’t detect any weakness, and in fact had partly the rudder gudgeons (with the rear cleats?) to pull the boat off the trailer a couple of times after that to careen it and do work on the bottom. The transom is strong. I have been sailing it since, including using an electric trolling motor on the transom, and don’t see a problem.

I am curious what others think of this, whether I am being stupid and have just been lucky, or if they agree it’s nothing to worry about. I sail on a small lake, so I am never more than a 1/4 mile from shore.
Steve
"Nellie Ruth" - 1985 DS2 Anniversary Edition #12819
Little Canada, MN
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Re: Transom Rot

Postby nickc » Wed Feb 01, 2023 1:49 pm

Thank you for taking the time to respond Vanalien! I am completely new so my thinking could be flawed but here are my thoughts. Firstly, my boat has the motor mount that lifts up and down attached through the stern. When I apply force to the mount the transom flexes much more than I would like it to. I plan to use my DSII as a daysailer on local lakes and as a camping-sailor on several lakes across the state that have boat-in campgrounds that are only accessible from the water. Our lakes here in Kentucky are all man made with dams which means generally they are narrow but very long so while you may never be more than several hundred yards from shore you may be miles from your trailer or the nearest marina. I plan on mounting a 3-5hp outboard on my boat so that if the wind dies and I am on the other end of the lake I have a means of getting back to the boat ramp in a reasonable amount of time without needing to rely on someone else being kind enough to give me a tow. I don’t feel comfortable clamping 40-60 pounds on my transom with it in the condition it’s in. Another worry I have is that if I don’t fix the transom there is a chance that the rudder gudgeons could rip out. Loosing a rudder or having an outboard go to the bottom would be a very expensive problem to have, more expensive than replacing the transom. Another factor that weighed into my decision to make the repair is that I have very little to no experience with boat repairs. Part of my goal with this boat is to learn enough so that in a few years I can get an older coastal cruiser and fix it up to my standards. There is a forum user here who has also made this repair and he did a great job of posting videos of the process on facebook, so anyone else who would like to make this repair won’t be completely going about it blindly. Ultimately I decided to undertake this repair to boost my piece of mind from a safety standpoint and to get some hands on learning about fiberglass repairs.
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Re: Transom Rot

Postby GreenLake » Wed Feb 01, 2023 8:54 pm

Just a note on two of the items mentioned.

For motor, I'd look for something more in the 2HP range. That should be plenty for the DS unless you are battling strong winds or currents. (For wind, it's the extra resistance, for currents, any extra bit of speed counts). If you seriously need something affordable and light on the transom, you could get a trolling motor, with the batteries kept in the cuddy (needs really hefty gauge wires, but you won't find anything as cheap with as good a fore-aft weight balance). The fancy electric motors probably don't have the range to return "the long way", but throwing in an extra lead-acid battery for a trolling motor is an affordable proposition.

For gudgeons. An intermediate work-around repair for the gudgeons would be to drill them out, use an L hook bent from wire to remove a disk of rotted wood, fill with a mix of chopped fiberglass and epoxy and then drill a new hole for the bolt. The little disk of fiberglass you create in the void will maintain the distance between the two hulls, no matter how much you load your rudder and that will allow the two skins to be strong enough to take the rudder loads.

Leaving the wood permanently wet does eventually create a risk for frost damage, if that's a concern where you are located.
~ green ~ lake ~ ~
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Re: Transom Rot

Postby nickc » Wed Feb 01, 2023 11:42 pm

I realize that only 2-3 hp is required, but I plan on buying a used motor so I have a range because I am going to go with whatever the most affordable option I can find that is no more than 5hp. The only hard limit I have is no more than 5 because anything more than 5 is very excessive for sure. I have a trolling motor but i have decided to go with a gas outboard because it can be refueled on the lake, once a trolling motor dies you’re just out of luck. Some of our lakes are 30+ miles from one end to the other, most notable Lake Cumberland and the Kentucky Lake/Lake Barkley chain. There are marinas every few miles though so with a gas engine you could stop and refuel along the way if you needed to motor back asap. I would like to go on the larger end of the 2-5 up range because of speed. I am a pretty busy person and I would like to have the capability to get back to the ramp pretty quickly in case i am short on time or something comes up, a trolling motor would be very slow and that could cause problems in certain situations. I would like to use the boat for camping trips and this is really where the ability to refuel a gas engine on the water would really come in handy for weekend trips where I need to make it back to the dock in time to be ready for school on monday morning.

Freezing is an issue here too. I am also somewhat meticulous so I cannot stand to know that something is messed up and just leave it that way, so I want to make the repair and have a transom that is good as new.
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Re: Transom Rot

Postby GreenLake » Thu Feb 02, 2023 3:48 pm

There are a lot of interesting variables that make finding an optimal solution a challenging issue.

There's price and range, operating costs and maintenance, and weight on transom.

For a sailboat, weight on transom is an important consideration, not just for structural reasons. Small sailboats are sensitive to any added weight, but specifically to weight on the transom. The latter affects the fore/aft balance in a negative way. A stern-heavy boat will squat and drag the transom through the water slowing you down. While you are sailing, the power you have available is limited. This matters most in the medium speed range, where you are sailing slower than the hull speed.

I've taken measurements with a small motor powering the boat at a bit over 3 knots. In that speed range, moving your seating position from the rear half of the cockpit to up at the cuddy can make a difference of almost .5 knots. Weight on the motor bracket is further back, so the effective lever arm is longer. That's why it pays to really keep the motor weight low.

When using a motor that's sufficiently strong, you may be able to reach hull speed even without good fore/aft balance. And when you are approaching hull speed, the overall resistance increases so rapidly with speed, that adding a small amount of resistance requires only a little bit of the total power required, so you may not observe the difference when motoring, but you would under sail.

I'm not sure what size motor would be required to get a DS up on plane. I suspect it's well above the range you were considering. That means, even with a motor, you are limited by hull speed, which (theoretically) is 5.4 knots for the DS. A 30 mile lake would take you nearly 6 hours to traverse, while sailing you might take up to 10 hours. (An average speed of 3 knots sounds low, but isn't uncommon for a point-to-point average, as you rarely have ideal winds the entire day). Half a knot better sailing speed would save you over an hour.

A smaller, lighter motor would not affect the sailing characteristics as adversely as a heavier one, but given that you are limited by hull speed, it might not be all that much slower.
~ green ~ lake ~ ~
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Re: Transom Rot

Postby nickc » Thu Feb 02, 2023 6:02 pm

All of that makes sense, but you’re working under the assumption that the motor will be left on the transom when not in use. I would likely leave the motor in the cuddy until I needed it to keep it out of the way. That would put the motor near the midline of the boat and negate most balancing issues. Again, for me it really boils down to what I can find on the used market for a good price. My main decision so far is that I won’t be using a trolling motor due to range constraints.
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Re: Transom Rot

Postby GreenLake » Fri Feb 03, 2023 2:43 am

Sounds like you have a plan; I like it. The cuddy is a good place to put any extra weight.

I'm curious to learn how all of this is going to work out for you and as ever, am looking forward to reading about your local waters and how they shape up for sailing.
~ green ~ lake ~ ~
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