Aluminum transom cap and transom bulge on 265

[Sketchywind]

I noticed a large bulge under the aluminum transom trim cap and between the outboards that extends down the transom about 2" . It seems to be getting bigger. The trim piece looks like it was caulked in the past. There is a small crack about 1-1/2" too. I hauled out a few months ago to recoat bottom and tested for transom flex by hanging on motors with no flex. Also, I tapped around the transom and around the bulge with no large difference in sound. The bulge starts around that messy caulking and flares along the trim piece about 6" and extends down 2". The bulge along the trim piece protrudes about 1/4". There looks like a slight bulge between the starboard motor bracket too.
Any suggestions how to proceed, or just leave it alone until the next haul out in a year. I'm wet slipped with no trailer.
Thanks!

 

[seasick]

I noticed a large bulge under the aluminum transom trim cap and between the outboards that extends down the transom about 2" . It seems to be getting bigger. The trim piece looks like it was caulked in the past. There is a small crack about 1-1/2" too. I hauled out a few months ago to recoat bottom and tested for transom flex by hanging on motors with no flex. Also, I tapped around the transom and around the bulge with no large difference in sound. The bulge starts around that messy caulking and flares along the trim piece about 6" and extends down 2". The bulge along the trim piece protrudes about 1/4". There looks like a slight bulge between the starboard motor bracket too.
Any suggestions how to proceed, or just leave it alone until the next haul out in a year. I'm wet slipped with no trailer.
Thanks!

Most likely you have water intrusion (you knew that) and some delamination. There isn't a lot you can do without removing the aluminum cap and most likely the motors. You could get a moisture measurement (using a trained surveyor or mechanic) to see how far the water has gone but it probably father than you would hope.
Caulk the crack and cap using a sealant like Boat Life (not silicon) and any obvious points of water entry. Enjoy the season and in the off season, you can take a better look.

 

[Sketchywind]

Thanks for reply. The surveyor's meter did show signs of moisture but from his soundings he did not feel the transom was rotten.

 

[Lt.Mike]

Is the inboard side of the transom braced in any way or are there just large washers where the OB bolts through?
My boat had some flex from a larger OB and a transom Tuffner plate was installed. It stiffens up the connection considerably.

 

[Sketchywind]

That's a nice bracket brace. I caulked the aluminum trim cap with Boat Life polysulfite. The silicone stuff just peeled off. Should hold until I haul out next year, I hope.

 

[Lt.Mike]

I don't think the brand matters but I will have one on whatever boat OB powered boat I own from now on. I see it as a way to stiffen up a transom that might flex better yet as a preventative measure before flexing or stress cracks appear.They are cheap so there is no reason not to automatically mount one with a new motor.

 

[Fishtales]

^^^ Agree with Mike on this one. That should be a standard item from the factory.

 

[gw204]

All that thing does is distribute the load from the engine mounting bolts. It's not wide enough to be considered any sort of a transom brace.

 

[eppem]

The saltwater seems to eat away at the transom guard/bracket. Try to keep it clean and chaulk the f out of any voids. I have the same boat.

 

[Harpoon]

I think something bad is starting to happen. IT may be worth while to pull those motors off, sand transom crack, dry it out, and re-bed everything when you haul the boat out.