Cap separation

[plusone876]

First of all, I have a 1971 20' SF that I recently put a 2015 150 etec on the back. Great performance so far. I have notice that the cables are really stiff and am going to have them serviced under warranty.

I was washing my boat the other day and noticed some flexing in the hull in the aft portions of the port and starboard sides. I looked under the rub rail and it looks like the cap is starting to separate from the hull. I do not know much about boat building, structure, etc. so I have several questions. How big of an issue is this? Could continued use damage the stringers, liner, etc. by letting water in? What is the best method to fix this? How much would you expect something like this to cost if the work was hired out? Thanks ahead for the responses. Currently, frustrated!

[billythekid]

rub rail needs to be pulled and cap and liner need to be reattached. the original aluminum rivets the boat was fasten together with finally gave way.

[Bushwacker]

I'd insist on the premium BRP cables if you don't already have them as that might make a difference. My cables are 6' longer than normal because of the way they're rigged thru the flotation tub and up thru swim platform, but they work fine. Also check out the E-TEC Owners Forum if you haven't already seen it . . . there's a wealth of info available there, much like CSC!

What shape is your transom in! Any cracks coming out of corners of cutout or deflection if you step on lower unit? Is your inner liner original or has the boat been "restored" where someone removed much of the inner liner and the torsional stiffness it adds to the hull? My boat had a wood backing strip on the inside of the hull/deck joint to provide something for the tapping screws to bite into. Eventually the wood will get soft, and the threads on those tapping screws are so sharp that they cut fiberglass and don't hold well. Your best bet is probably to replace them with machine screws and nuts & washers on the inside.

[plusone876]

The boat had a new deck, new transom, bracket, etc. installed in 2005. There is no cracking anywhere except a line where the floor meets the transom. I do not think this is structural because the transom is solid. Will continued use of the boat in this shape be detrimental to the boat? I'm assuming it would. Any idea on how big of a project this would be and cost?

thanks,

[shine]

can you post some pictures of the cracks? Pictures of how it was rebuilt would be helpful too.

The cap getting loose will certainly allow more hull flex, not good, should be fixed before you use it offshore (or anywhere it will flex)

Joel

[plusone876]

Attached are photos of the transom/floor crack, cap separation, and only area of cracking on the outside of the hull.

[plusone876]

Cap separation

[plusone876]

You can't really tell what that photo is at all.

[Bushwacker]

Need a better resolution pic of the cap! Were those cracks on the outside of hull there before the transom was replaced or have they just shown up? Never seen cracks like that but they look to be right at front edge of transom core. If they showed up after transom was replaced, I'd say something is going on with that transom. Does the bracket/motor deflect if you jump up and down on lower unit?

How much and what type of glass was installed on inside of new transom, how far was it wrapped around into the hull sides, what sort of core was used, how thick was it, and what type of resin was used? Those cracks on the inside between look quite large, almost like there is significant flexing there, much wider than what occurs due overly thick brittle gel coat. Is that a vertical brace on the transom that also looks like it's cracked at the transom/brace joint?

The original CC models had a large inner liner that appeared to be integral with the top cap that was bonded to the top of the stringers. The box shaped structure created by the inner liner and outer hull adds a lot of torsional stiffness to the hull. If the vertical section of the inner liner was removed when deck was replaced, it might explain what you're seeing. To illustrate my point, take a shoebox and try to twist it with no lid on it. Then tape the lid on and try again and notice the difference, which will be significant.

[plusone876]

It is hard to get a better pic of the cap. I have only owned the boat since 2010, so I do not know much on the way it was restored. So it appears that I have a problem not only with the cap but the transom? I figured the cracking on the deck was mostly cosmetic. The cracking above the deck line is only the paint peeling away. There is no cracking of the actual transom above the deck or below as far as I can tell. The flexing of the sides is only in the stern but stops about 1' from the transom. Suggestions? A guy in town did the restoration, maybe I can reach out to him.