Transom-Deck Joint crack Pictures - Zodiac Medline 3

[shahid]

I'm enclosing pictures taken of a Zodiac Medline 3 RIB with what appears to be a crack on the Transom-Deck Joint.

Haven't noticed any water in the bilges yet, though the appearance of said crack is worrying me.

As you can see in the overall views, there's caulking on both extremes, while the center section appears to have opened out. Normally one would have expected this area to have been glassed over but zodiac seem to have used caulking.

What would be the best course of action to repair this. I really want to avoid dismounting the engines for repairs but looks like that's what I will have to do.

I would very much appreciate any advise on the same.

Cheers!
Shahid

[Bigmuz7]

get the motors off and take the pain ... welcome to having a lot of power and weight on the transom .. rebuild ahead I'm afraid ! Still ,.. it is not impossible to sort

[chewy]

Its not a crack as such is it? Just looks like the two mouldings have parted company?
Still needs looking at either way.

[Bigmuz7]

well I wouldnt take my nearest and dearest to sea in it,.. round the parts I go

[shahid]

Chewy, yes it's not really a crack...more of a parting. The course of action that I'm considering as of now (pending more inputs from you experienced ribbers) is dismounting the engines, removing old caulking and cleaning the surfaces, injecting new sealant and glassing over/ applying gelcoat.

Do you think inserting a couple of thru bolts would be a good idea?

The season here will only start in october after which she will be in a swinging mooring.


Bigmuz, when you say "rebuild" do you mean a transom rebuild or what I mentioned above? The person I bought the boat from had opted for the twin engine setup, I would have probably gone for a single.

[chewy]

Sounds like a good plan mate, the engines will need to come off, the old sealent removed and surfaces cleaned.
Use some form of Sikaflex (221 or 291) to seal it then like you said a few bolts through won't go a miss.
I wouldn't glass over it or gelcoat it just leave it as it is.

[shahid]

Thanks! Feels good to have some reassurance, will post an update once I get the work done.

[chewy]

Is the moulding just the splash well joined to the hull?

[Bigmuz7]

the trouble is .. you dont know how far down it goes

The thing with ribs is that they only usually have two 'knees' that take the engine loading on the transom to the deck and the hull. i.e unlike most power boats which have 'sides' as well, so its an inherently weak design, and if they fail .. your outboards are connected to fresh air .. so any damage on the transom is inherently a failure throughout the whole stern as far as I'm concerned.

Every case is different, but your case looks like a common problem and one I have experienced myself

Youve got to remember .. next time you come flying off a wave.. and land in the next one .. your engines will develop an immense thrust on your transom and hull, and every jump you do will weaken it further .. YOuve got a break the whole way across the top which is total structural failure IMO

You need professional advice to get this sorted IMO

[chewy]

JUst read your post Muzz.
From what your saying it could just be the engines holding the two mouldings together worse case scenario?
Bad design if it is?