thompsondockside.com

Interior shot of hull at transom - keel butt. Is the beam-wise doubler along the bottom of the transom original? (That second doubler from the keel to the first starboard stringer definitely is a repair.) Notice also how the aft two ribs on the starboard side don't line up. The bilge paint (instead of varnish) is definitely non-original.

Replacing the transom (from my newbie perspective) seems simple enough once the new one is fabricated - just brace the sides, unscrew the old transom, and screw the new one in place. And rib replacement - remove the decking, steam the oak, and slip it down the inside of the hull and fasten.

But if you have to deal with transom, ribs, and keel (and don't want to build a custom strongback) how do you attack the problem in easier steps?

1967 Off-Shore Cabin Cruiser model 2090

George

George,

It would also be advatagous to know if this is a Peshtigo or Cortland built boat, as they did some things differently.

What you are looking at are the Keelson and Sister Keelsons. The keelson is the center piece and the outer two are the sister keelsons.

I would first look at what all needs to be replaced. I think you will find you have rot on the ribs under the keelson, just from looking t the picture. Keelson and sister keelsons will need to be replaced. These are best replaced with one continueous piece of new wood for each piece. I have seen people use wider lumber then original for these items and if the rot is not to bad on the ribs cut them back a little and tie them into the wider lumber.
If I recall correctly on peshtigo boats the ribs are inleted into the keelson and the keelsons go over the top of the ribs. Andeas could tell you exactly.

If the hull bottom and strakes have rot at the transom you can move the new transom forward to good wood shortening the boat slightly. If you did this you could build the new transon inside the hull and cut off the portion of the hull flush with the new transom.

Let's here from some of you guys that have tackled this problem.

Good Luck,

Phill

What the heck is a "doubler"?

He indicates the boat is a 1967 Off-Shore Cabin Cruiser model 2090. That is a Peshtigo built boat. Cortland no longer made wooden boats in 1967 and they dropped any reference to the Off-Shore model name circa 1962-63.

Andreas

George.
Just as a help tip. If you scroll back thru the restoration threads you will see one marked "Nomemclature"
It was posted on Nov. 2, 2010
Click on this and print up the pics that Andreas drew. It gives you the correct terms to use for the parts of the boat that you are discribing in your posts. This will make it easier for everyone to help when you have a question.
This is a great site with lots of great folks that have experience working on Thompson's
Good luck and keep us posted on your project.
Karl.

OK, thank you for the reference, Karl. Keel and sister keelsons I got. What I was talking about was the plywood attached along the bottom interior of the transom. Because it was painted white along with the bottom, maybe it wasn't as obvious from the picture as I thought. So I posted another copy of the picture with some lines drawn emphasizing the outline of that full width board that's about five inches high along the bottom of the transom. There's also an additional second "doubler" board added to starboard of the keel running to the [what's the correct term for the beams running fore / aft parallel to the keel + keelsons?]

Were these width-wise boards added as bottom repairs to provide additional backing for hull fastening as the bottom plank ends got chewed up?

George

Andreas, a "doubler" is just framing construction terminology - two identical boards fastened together doubling their width. When you don't want to switch from a 2x10 to 2x12 but need more load bearing capability, just double the 2x10.

George,

I think this is someone "PATCH JOB" to make the boat a little drier when in the water.

Just from looking at the pictures you provided it looks to me like you need to do quite a bit of restoration on not only the transom but also the ribs, keelson and sister keelsons and well as the keel. I do not like the look of the garboards either. From what I can see it looks like this boat sat for sometime with water in it.

Strip all the white paint from in the bilge area and inspect every inch of the ribs, garboards and strakes to be sure they are sound. Replace with new wood as needed and chaulk and seal all joints between keel, garboards and keelsons and refasten with new screws and bolts.

Good luck,

Phill

George,
For some reason I am not able to bring up your pics. Could be me as I am not very computer literate.
If Phil says this looks like a patch job Then it is. There is no plywood on the inside of my transom at all. That's one of the nice things about these boats, the solid Mahogany Transoms.
Sounds like you have your work cut out for you.
Karl.

Those pieces of plywood attached to the inside of the transom are not factory original. They are sign of some problems behind them. Remove them and try to figure out what they covered up.

There is a factory Philippine mahogany board about 5 inches high running the width of the boat along the bottom edge of the inside of the transom. But the plywood on top of this piece is not original.

I agree that it appears you have serious issues with the keelson, ribs, plywood hull planking, and transom. Strip everything to bare wood and replace it if there is decay.

The keel is on the outside of the boat. The keelson in on the inside of the boat. The keelson is at the center running fore and aft and it is made up of three pieces of wood screwed and glued togther. Your's has some type of googe poured into it between the three pieces of wood (that's a sign of a problem).

The sister keelsons are single boards that parallel the keelson and are located 18 inches or so from the boat centerline.

Building construction terms do not necessarily translate for use into boat construction terminology. I work in the building construction industry and never would picture a 'doubler" in a boat.

Andreas

Thank you, Andreas, Karl, and Phil! That's what I thought (terminology-wise) but everybody kept telling me those were the sister keelsons bolted to each side of the keel for a three-thick backbone. Now I know what to call them so as not to confuse you.

The boat sat on a trailer for too long. The keelson delaminated. "Wood boat expert" filled voids with West System.

So in what order would you attack this problem since transom, keelson, ribs, and bottom are all suspect? Brace the gunwales and do the keelson and transom first, then rib replacement, then flip and reskin the bottom? I have that chicken and egg problem - can't shape the ribs without the bottom but the bottom isn't quite fair since I suspect a few ribs snapped at the chine and there's probably some hog in the keelson. Would it be better to do that four foot wide garboard plank on the bottom first and only partially fasten it to every second or third rib, using the plank to fair the bottom and receive the new ribs?

George

George . Here's my thoughts....
First check the entire boat from stem to stern for problems. So far you have focused on the rear of the boat. How is the rest of it? I know that no one likes to hear this but is this boat something that you can handle. ie, skills, time.money. Anything can be restored/repaired but is it realistic. Having said that.....
Whole Hog, I would brace the boat, flip it and peel off the planks. That way you can see every thing,and get to it.
The least I would do is to remove the Keel and the garboard planks. You can do this with the boat upright if you don't mind working on your back. You need to see that keelson and have access to it and the rib ends that attache to it.
This looks like it is not going to be a short term project.
Karl.

Ps.
Sistering is the correct term for putting a new piece next to an old one for bracing/repair. But in the case of Thompson boats the stringers that run parallel (sp) to and outboard of the keelson are called sister keelsons.
Karl.

Here's an inline picture of the transom with the "questionable" items highlighted in red. Also note the sister keelson itself has been "sistered" (at very bottom of image). And the aft-most two ribs don't line up port to startboard.

George