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transom

Posted: Thu Feb 19, 2009 12:36 pm
by bobh59
i have a 1959 thompson (IM TOLD) that has some dry rot in the top of the transom.the area is on the left upper corner-the boat has a outboard.the outer boards are mahogany the inner is plywood(3/4-1in) my question is can i do a partial replacement by all new mahagony upper corner and a piece of plywood using biscuits -glue and screws?any advice will be greatly apreciated. thanks bobh59

Posted: Sat Feb 21, 2009 6:18 am
by Phill Blank
bobh59,

It sounds like someone else did a repair on this transom once before, if in fact you have a Thompson, as I do not recall Thompson using plywood in transom construction on boats especially in 1959.
Thompson transom where, to the best of my knowledge, made with solid mahagony lumber.

But to answer you questions about "Dutchmaning" in a piece of wood using biscuits and glue. You are better off replacing the whole board rather then patching in a small area. This is the transom we are talking about. This is the area of the boat where all of the torque and stain of the motor is transfered into the hull. Any weakness here will effect the whole boat and could in a worst case cause failure. If pirecing in wood it is best done with a scarf joint rather then a but joint with biscuits. Scarf joints have larger surface areas for the glue to bond too to add strength to the joint.

I would suggest you do a little more digging to find out who manufactured your boat and if it infact is a Thompson where it was made, Peshtigo or Cortland and which model you have.

If you go to "What Do I Have" on the main page and get all the info asked for and submit it we can try to help you identify the model Thompson you have, if it is a Thompson. With that info you know more on how what the boat was originally built. It will also aid in our trying to help and advise on how best to do a repair.

Good Luck,

Phill

Posted: Sat Feb 21, 2009 6:30 am
by bobh59
thanks phill i will do that

Posted: Sat Feb 21, 2009 3:23 pm
by LancerBoy
Welcome aboard.

You are better off asking restoration questions in the "restoration" section.

IF this is a plywood lapstrake boat made by Thompson Bros. Boat Mfg. Co. of Peshtigo, WI or Cortland, NY, the transom will NOT have any plywood in it. It is made of solid Philippine mahogany lumber. Two layers with one running vertically the other horizontally.

Who made your boat and where was it made?
Is there a metal tag with builder's name, location and serial number on it? If yes, what is on this tag, COMPLETELY and EXACTLY?
What is the hull ID stamped into the wood of the transom, inside the boat?

We can better answer your questions if we know what you have.

Also, there is no such thing as dry rot. That is a fallacy. If it were dry, it would not rot. It is just plain ol' rot.

You are welcome to email photos to me.

Andreas
thompsonboat@msn.com

Posted: Mon Feb 21, 2011 3:16 pm
by THE LAKE
I think dry rot is rot that has dried :lol: Sorry, too easy to pass up. Moving along, I spent 44 years in Maine until transferring out here to San Diego in 98. Have since retired (forced) and go back to Maine every summer but I wanted to ask what you call it when wood dries out to where it turns to dust ? It's not uncommon to see old buildings out in the Mojave Desert that are crumbling from LACK of moisture in the wood.Sorry to get off topic. It's a slow day, even though a holiday, most of my friends had to work.

Brian