Failing Transom on Alumacraft 1436 Jon Boat: Transom Plate

I have this failing transom that I need to take care of. After taking off the mud motor, that I used to test all the longtail kits with, and flipping over the boat to put the Wetlander Slick Bottom Coating on, I now get to deal with this transom that is failing

What does a failing transom look like?

You may be wondering what a transom looks like when it begins to fail. I know I didn’t know what it looked like. I didn’t know my transom was failing. This boat is a 2016 Alumacraft 1436 LT (light version). I bought the boat new and got the warranty with it. The transom metal was separating away from the wood on the inside, bubbling away from the wood. I could put my fingers above the drain hole inside my boat, where you put the plug, and fit my fingers in between the wood and the metal. I sent Alumacraft some pictures and asked them why my transom looked the way it did. They said it was failing, and I said great because its not even two years old yet so I still have a warranty…. or so I thought.

After having a long email discussion with Alumacraft, I received this email, “In making a modification to the boat that has compromised the structural integrity of the boat, and by  installing a motor on the boat, that the boat was not designed or intended to have installed on it, yes you are voiding the warranty.” So I no longer have a warranty on my boat that is less than two years old, because Alumacraft says I modified my boat by installing a mud motor on it…? Alright, no more support for you Alumacraft. Sooo… plan B?

Failing Transom meet Aluminum Plate

How do I go on fixing this? Do I add more wood, maybe use some starboard? How about some more aluminum? After digging around and thinking about it, I figured adding an aluminum plate would be best:

  • Wood – Adding more wood would be alright but wood degrades, wouldn’t last as long as aluminum, weighs a little more, and I felt I needed a little more strength in there. I also thought if I’m strengthening my transom, I might as well do it right so I only have to do it once.
  • Starboard – This stuff could work. The only problem I see using starboard is that it is slippery. If I’m going to be using it where I mount my motor, I don’t want it to be slippery…
  • Aluminum – Could be expensive but would give the strength needed and doesn’t weigh too much. Durable, doesn’t degrade like the other materials would, and easy to work with.

So I went out and got an aluminum plate to fix my failing transom.

The Aluminum Transom Plate

The aluminum plate I got is T6 hardened. Quarter inch thick (1/4″ or .25″). I do not know exactly what the grade of aluminum is, but if you go to buy a piece is would be something like a 6061 or 6063. This is some tough stuff and I know it will do the job. It is most likely a little overkill for this failing transom but it’ll work. The plate is 13″ by 11″ which fits between all the rivets so I don’t have to cut out any. I will still grind and drill out the buffer plate just so I can bolt through the transom and not have to run a bolt through the buffer plate as well.


We have the aluminum plate, now what? First I measured and drilled the holes to mount it. Next I put a bevel on one surface so that there would be a nice place for the M5200 to bead at all around the edge. I also wanted the aluminum plate to have a protective coating on it. Instead of just using some regular paint, I decided to powder coat it. That is a very large topic so I am going to leave it as, I powdered coated the aluminum plate.

So the aluminum plate has the mounting holes in, a bevel all around one surface, and is powder coated.

Aluminum Transom Plate to fix Failing Transom

Transom plate. That is what I am calling the aluminum plate that is fixing my failing transom.

  • T6 Hardened Aluminum – 6061 or 6063
  • 1/4″ thick
  • 13″ x 11″
  • Mounting holes
  • Bevel
  • Powder coated

That about sums up this transom plate and what I hope fixes my failing transom. I made the plate as big as I could so the force of the motor is distributed better through a bigger foot print (surface area). Anything thicker and I would run into trouble with mounting the mud motors. Next article is about mounting this transom plate!