Transom is OUT - do preventive maintenance

[abl1111]

RL,

I had an experience w/ 5200 where it did not work out as well as your experience(s). The transom to hull joint on my 20 Grady ( under the outboard ) had a 1/8" gap where water was able enter. I cleaned it up really good ( degreased ) and used 5200 to close this potential transom rotter.

The next year, I saw that the 5200 had come away from the seal and was not keeping water out. I cleaned it all up, removing the 5200, and re-did with a 3M silicone. (4) years later all is still good.

My thought was that the 5200 could not take the small but constant movement/vibration of the meeting transom and hull - 5200 too rigid ?
The silicone was more pliable and able to. Note: personally I cannot see how this joint on the boat moves at all, cause the hull is pristine and solid, but I could not think of another reason.

Also, when I installed a thru-hull for my livewell, everyone in the marine industry told me to use silicone and not 5200. Who knows ? As for installing a motor to a transom, I would use 5200.

I would like to know when to use 5200 and not to.