CAL25 transom reinforcement

[rakos]

Hello all; where can I find photos of how people have re-enforced their transom? I have a 1979 CAL25 with a Yamaha 9.9 which probably weighs about 130 lbs. The transom moves about 1/2 inch when torque is applied, I am worried it will eventually break. Original motor mount is 2in x 6in x 14in piece of wood at the bottom of cutout; 6 inxh is exposed on which the motor is mounted, and about 4 in goes inside both sides and is glassed to the back of the transom. It is quite rotten so I reinforced with git-rot but not the best method. Seems like a 1/4 aluminum or stainless sheet on the outside is simplest. How would I attach it?
Thanks, John in Ottawa, Canada

 

[SG]

John,

Do you have a photo or photos of i) the exterior of the transom; and ii), the inside of the transom. When you say the existing transom moves a 1/2" when torqued, what do you mean? In and out?, the motor mount rotates?, it moves up and down? Etc. ?

Is the transom glass assembly sound? Is it a case of reinforcement in the form of backing material? That's where this is going.

 

[Whatfiero1]

Round here we use an aluminum road sigh. I think my old Hunter 23 has a 25 mph sign backing the motor mount the plate is installed inside with 5200 spread all over back then drill back out holes put motor mount back on and done.

 

[rakos]

Hi, it is a typical CAL25 transom with a cutout. When torque applied, motor 'pivots' around the mount, ie, bottom of motor moves forward, pushed by prop, and top moves transom and the 2x6 it is mounted to back about 1/2 in. Transom glass flexes, but I am afraid not for ever, especially if motor is accidentally dropped down. Puting anything inside is not possible, thinking of plate outside, glassed or screwed.

 

[SG]

Which "typical" Cal 25? If it's the "top" picture, then the engine still has to mount to something? Is your transom's fiberglass assembly compromised? I think the cores were plywood? (I'm not familiar with Cal 25's stern.) Is there no access to the inside of the hull back there?

Then there is the Cal 25II

 

[Solarfry]

1/4" aluminum plate 4'x4' minimum if on outside.

 

[rakos]

I think all 3 may be the same, but the best to explain is the second (4 hp Suzuki). That wood piece the motor is mounted to is a 2x6 that goes forward of the transom, outside about 10in then continues inside the boat about 6 in. It was originally just fiberglass clothed inside to the transom, but obviously that boat has a bolt through it holding it to the transom. Also as seen on the pic the fiberglass of the transom, aft of the 2x6, seems to be about 1/8 in. The rest may be thicker and cored.

 

[agprice22]

Seems like a plate outside would need to either bolt to something inside or wrap around and attach to the hull. Like a strap that traversed the transom and wrapped around to be bolted to the hull. Otherwise, it seems it would just be adding weight and distributing the torque to the edge of the plate, where the fiberglass would split and drop your motor, plate, mount and all, in the water.
I don’t like reinforcing a bad transom.
A better repair would remove the transom liner from the inside, replace the bad wood, and reglass it.
Since that looks like it would require some difficulty, I would opt to remove the transom glass from the outside. Glass in some new plywood. Replace the outer fiberglass piece, and fair it in. You could then either spray on gelcoat or paint it. If you remove the entire transom, your seam will be at the corner. It will be easy to feather it, glass it, and fair it smooth.

Geez, it MUST be Winter. I am almost excited to undertake the task! I have not mixed epoxy or paint in 6 months!

 

[rakos]

Somehow I am not that thrilled...

 

[agprice22]

Somehow I am not that thrilled...

I hear ya! Is the boat out of the water?