Transom-Deck Joint crack Pictures - Zodiac Medline 3 - Page 2

Bigmuz7 · 15 August 2009, 15:29

Yes I see what you mean .. if somone physically lifts one of the engine legs up whilst trimmed up, or pushes down on it, can you see any actual movement at the bonding gap ?

shahid · 15 August 2009, 15:44

I'll try that out first thing tommorrow. I didn't notice any movement while tilting the engines up/down using the motor.

shahid · 16 August 2009, 23:09

Quote:

Originally Posted by mhb100

Guys,

Looks like the issue with the zodiac transom might not be what it appears.

The failing transom....Good news.

After investigation today I now know there is no damage to the structural part of the transom. The spliting is not on the main transom but where the top and hull moulds join together. The split runs parallel to this seam - there is no splitting elsewhere, and having moved the engine today and checked all bolt holes,etc im pretty sure of that.

Having done a postmortum on the cracks (with a grinder) its clear to see whats gone on. On top of the solid transom (where the lip is) is actually a hollow box section (yes hollow,what a design!) the top is about 3-4mm thick the rear about 20mm and the front (where the cracks appeared) about 5mm. In between all this is a hollow core section running the length of the transom. The join where the cracks appeared seem to have the least silkaflex or similar bonding the join. Remedy seems to be to fill with epoxy and finish in gel coat. If the crack had been anywhere else then the outcome would have been very different! . I will look at a transom plate as well.

M

An uncannily similar crack in another boat here's the thread: http://rib.net/forum/showthread.php?t=20131

shahid · 16 August 2009, 23:23

Ok so the transom design in the medline 3 appears to be as follows:

The splashwell top that you can see in the pictures, is also the top of the Aft Locker. Inside the Aft Locker which extends all the way to the transom itself, one can see two knees that support the transom.

Hence, the transom itself is seperate from the lip that has seperated. Will post some pictures of the interior tomorrow.

shahid · 17 August 2009, 21:24

Here are some pictures taken this evening from inside the Aft Locker. Was a bit fiddly getting the camera in there so the angles are not the best.

shahid · 17 August 2009, 21:25

You can see the two knees on either side of the bilge for additional support to the transom. The grey/orange top is the splashwell as seen from inside the aft locker.

The lower mounting bolts of the engine are also visible here.

shahid · 17 August 2009, 21:31

and incidentally there's absolutely no movement whatsoever on the crack while lowering and raising both engines individually or simultaneously

JSP · 17 August 2009, 21:31

SO the transom is fine and it's just where the moulding of the locker sits on top?

shahid · 17 August 2009, 21:33

That's the way it appears to me..what do you think? does the design make sense?

shahid · 17 August 2009, 21:34

Quote:

Originally Posted by jsp

who lit the fuse on your tampon this morning?

lol

JSP · 17 August 2009, 21:36

Quote:

Originally Posted by shahid

That's the way it appears to me..what do you think? does the design make sense?

Have to say I know sweet bugger all about the build designs of RIB hulls. But from the pictures and the way you describe it, I'd say that makes sense. Just think the boat builder could have come up with a tidier design?

shahid · 17 August 2009, 21:39

Wellll it Is a french boat

I'm pretty happy with the layout and design otherwise, it has loads of creature comforts (admittedly out of place on a RIB, but welcome nonetheless)

Bigmuz7 · 17 August 2009, 21:54

Quote:

Originally Posted by shahid

and incidentally there's absolutely no movement whatsoever on the crack while lowering and raising both engines individually or simultaneously

Did you get somone to physically lift the leg by hand whilst you watched the split area to see if there was any movement ?

Quote:

Originally Posted by shahid

does the design make sense?

No it doesnt to me .. for all it would have taken for the manufacturer to glass over the transom

I mean in the scheme of things it wouldn't have cost too much

However .. now that you found the other thread on the issue which I read from start to finish and was most informative, I think it must just be cosmetic right enough, although I am still staggered a manufacturer would leave a finish like that, particulary if there is any possible chance of water ingress which could have disasterous effects, particularly if it freezes.

On the other hand, on reflection .. maybe it was done that way to allow some flex, which is inevitable on any transom, and fine, as long as the knees to the hull base are strong enough .. and in this case actually avoids any alarming flex damage to brittle gel coats .. all IMHO ofcourse just looks a bit scary, and I agree with your concerns on your original post, but after reading the other thread, it certainly looks worse that it is, if indeed there is any fault at all ?

Did you get a response from Zodiac ?

shahid · 17 August 2009, 22:00

Quote:

Originally Posted by Bigmuz7

Did you get somone to physically lift the leg by hand whilst you watched the split area to see if there was any movement ?

I used the power trim unit for raising and lowering. Also tried to move the leg manually without opening the pressure relief valve, no movement.

Quote:

Originally Posted by Bigmuz7

On the other hand, on reflection .. maybe it was done that way to allow some flex, which is inevitable on any transom, and fine, as long as the knees to the hull base are strong enough.. and in this case actually avoids any alarming flex damage to brittle gel coats ..

I thought the same and hence decided against through-bolting after filling with adhesive sealant. what do you think?

Quote:

Originally Posted by Bigmuz7

Did you get a response from Zodiac ?

Not yet....big boatyard that they are with millions of boats worldwide