Trojan Boat Forum

I noticed while climbing up on my swim platform the transom will flex some. I know that being an inboard the transom is not the reinforced kind, so hopefully its nothing to worry about. Is this normal? Does yours flex? I may reinforce with a board from starboard to port. Any thoughts?

May need larger backing plates and reinforcement won't hurt . But I don't see it as a issue

I agree, I wished they beefed up the transom glass a bit. There's a lot of stress from people getting on and off the swim platform which leads to gelcoat crazing around the brackets. I oversized the plywood backing plates by about 2x to help spread the load. I wouldn't worry about it structurally, it's really a cosmetic issue.

Bob

The problem with flexing where hardware like bolts penetrate the area is that the more flexing there is the faster the seal will fail and allow water in. Depending on conditions, this could take years or less time than you think. In areas that are cored, this is not good. I've seen the results of too much flexing from the extra weight of platform extensions, dinghies and PWCs, add-on hydraulic platforms, outboards mounted on deck rails, etc. If flexed often enough, it's just a matter of time before it will have an undesirable effect. Spider cracks in the gel are just the first sign that loads are flexing enough to stress the area. Proper mounting and sealing practices, and taking measures to minimize movement is key to maintaining a seal that will last. And for those considering adding additional weight, just because an accessory is designed to be mounted back there like dinghy davits or a platform extension, doesn't mean it's a free pass and that your transom or any other area is designed to handle the additional loads.

Flexing aside, if everything secured to a cored structure was done with the fasteners going into epoxied plugs instead of in direct contact with the core the way it should be done, you'd never have to worry about the core getting wet with a failed seal but we all know for time and expense reasons, this practice is rarely followed.

I had a similar issue with my 10 meter express 15 years or so ago.

two issues were found:

1) two of the four support brackets had cracked welds. this transferred part of the getting on and off the swim platform stress - (imagine it now as a lever)

2) the wooden support brackets inside the transom were in bad shape, and IMHO somewhat smaller than they should be.

had the support brackets welded, replaced the wood backing plates with (as I recall) a two layer sandwich of heavy starboard, larger than the original wooden backing plates.

PROBLEM SOLVED !

It is important to keep something in mind as we deal with these boats.

THEY WERE NEVER ENGINEERED, BUILT OR DESIGNED TO HAVE A USEFUL LIFE OF 30-45 YEARS.

Some of the issues we are dealing with are a result of this fact of life.

That said, there are many other brands whose 35 year old vessels have for the most part, gone on to the boneyard.
RWS

I believe 1o meter's were had no coring in the hulls. on the other hand 11 meter and up they had coring in those hulls

Thanks everyone. I will look into putting larger backing plates in. Maybe trex pieces?