Cap separation
 

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!

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.

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.

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,

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

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

Cap separation

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

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.

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.

If it's just thick paint that didn't adhere well, then maybe it is just cosmetic, but I'd be inclined to grind off the paint in that radius with a Dremel tool sanding drum to see if there are any cracks under it!

I noticed what looks like a scupper going out thru the transom, which tells me the original aft seats and splashwell were removed, original vertical scuppers removed/plugged and new cockpit sole extended all the way back to transom. Sometimes most of the interior of a boat is gutted as part of a repair like that, so hard to tell how much of the original liner is still there. If it's done by a guy that doesn't know what he's doing, it's easy to remove some important structural elements! A pic of the entire aft cockpit of the boat would give us a better idea of how much structure is there.

So is there noticeable flexing of the hull sides and/or cap in the back of boat if you push on the hull sides? Were those outside cracks there when you bought the boat?

I think the cracks were there on the outside. The guy that did the work is very reputable and has done several SeaCrafts, Makos, Chris Crafts, etc. Just minor flexing on the outside of the hull, no movement in the cap at all.

Pics

Still can't tell much from those pics. Is the view of the cap separation from the top looking down? Unless camera has a macro lens/close up setting, most cameras will be out of focus if you're closer than about 3-4' from subject, so maybe try backing up to about 4' from it and taking a shot from top and side to see if you can get some clearer pictures. Maybe it's just damage from a severe dock walloping incident it it's past life!

Also can't see enough of the inner liner to tell if it's intact. Does it look like the one in attached pic? I suspect the reason that Moesly didn't put any cut outs in the aft portion of inner liner is because of the significant stiffness it adds to the hull. The curvature of the flare in the hull further forward would add significant stiffness up there, so openings that reduce the rigidity of the inner liner in that area are probably ok.

That picture is from underneath the rub rail and is about 3" away. So no major separation. Definitely no separation on the top. The picture that you posted is too small for me to see. So it sounds like you don't think that it is that major, correct?

major loss in stiffness by eliminating the boxes. The cracks at the bottom of the transom/deck and the one on the side show that the transom is flexing the rest of the boat. so the transom is not flexing, but it is transferring forces to the rest of the hull in concentrated area that are too far spread apart.

I don't like to be critical but that is just an awful design. The starboard thing is not helping in any way structurally. You cant cantilever an outboard on a bracket/lift without something more significant back there. Thickness of the transom is only one part of it.

You really need to add some knees or boxes or both.

That was my thought also...That whole back area should of been a built in, and tabbed in to the floor and sides...that way creating a stronger "box"

This is something that's not a catastrophe...but should be addressed.

Can't say it's NOT major until we know what's under that paint! If it was just one small tight crack in one spot, that's one thing, but to have cracks in 3-4 different areas, it seems like the boat is trying to tell us something!

What does the port side look like? Any cracks like on stbd side or anything going on at the hull/deck joint? Shine is a professional fg guy, so if he's concerned, I wouldn't ignore it. I've heard other professional glass guys say that when they start grinding away glass to do a repair, they often find that damage is much more extensive than they initially thought. That's a very high torque motor you have, and it's not only trying to twist the bracket, the setback creates a 2' or so lever arm to put an additional bending moment into the transom, much more than if the motor was just mounted directly to the transom. If the bracket has a big flotation tub and swim platform like a Hermco, that will spread the motor loads across the entire transom, but if it's only about 1' wide with minimal flotation like a Stainless Marine bracket, that not only concentrates the load, the lever arm created by the setback multiplies the bending moment on the transom!

I stole that picture from the reed smith post in For Sale section but it came out much smaller than I expected. Here's a link to his pictures which include a couple of good shots on a B/M SF cap/inner liner.

I my opinion it is a tragic mess and needs to be completely reworked. I've seen better laid out transom support on a sailboat.

Sorry, I get a little worked up when I see what some folks get trusting what the last guy did it right.

One other thing improper support on a trailer will cause this too, specially with a bracket hanging in the wind.....

You're right - the vertical "G" loads when the trailer hits a bump can be significant way back there! I use a "transom saver" to support motor from aft keel roller on trailer if I'm gonna trailer the boat very far..

Can't say it's NOT major until we know what's under that paint! If it was just one small tight crack in one spot, that's one thing, but to have cracks in 3-4 different areas, it seems like the boat is trying to tell us something!
That transom saver is a great idea. I think I'm going to take it to Bobby Ghelkin here in the Charleston, SC area to see what is going on. He has redone several SeaCrafts, Makos, etc. With unlimited money, I would like to redo a lot of different things and adding a large hermco bracket is at the top of that list.

The port side has a little flexing in the same area but far less and no cracking anywhere.

My list would include:

-Widening the transom and installing boxes of some type like you see on 23s
-checking the transom
-resealing the cap back to the hull and adding a new rubrail
-painting the interior of the boat, cap, hull, and removing the bottom paint

My scuppers are about 1" or so below the water line, would you think the hermco bracket would add enough bouyancy in the rear to make it self bailing?

thanks,

and that's the truth :)

The transom itself might be just fine, hopefully. You will just need to change how the transom is tied into the rest of the boat. Easiest way is to "box in" the transom with a bulkhead (not exactly a bulkhead because it does not go all the way down to the hull bottom) with a couple longitudinal frames. This will stop the flexing you have at the top of the transom.

like this... http://gallery.bateau2.com/albums/us..._shine_398.jpg

My hull does not flex at all when you push in on sides till you get a couple feet forward of transom. If yours has any flex at all within a foot or so of the transom, that's disturbing!

As far as mod's go, I'd want to make sure the transom core is tabbed into the hull sides and bottom with about 3 layers of 1708 wrapped into hull around from front of core using epoxy or vinylester resin, and I'd attach some 45 degree knees from top of stringers to transom. Those vertical boxes on front of your transom don't do much unless they're attached to the stringers. A 45 degree brace between the stringers and transom would be a much more efficient use of materials (less weight), and would transfer the bending loads that motor/bracket are putting into the transom directly into the stringers, which on a '71 hull, consist of 4 massive 2" x ~8" U-shaped fiberglass beams that are installed in the hull about halfway through the layup and run the full length of the hull.

When previous owner removed those seat boxes and splashwell from back of boat, that took out a lot of torsional stiffness out of the back of the hull because there is a 1" x 4" "beam" oriented vertically and glassed to the inner liner at the front of the seat boxes running the full width of the hull. If you install a box beam across the top of the transom and glassed to the cap as Shine describes, tied to the floor with a bulkhead, that should more than compensate for the stiffness lost to the missing seats and splashwell. I'd make it wide enough to put a couple of small storage boxes or bait wells like the later model Tracker 20's have.

Regarding your scupper position relative to waterline with a Hermco bracket. there's no way to predict that unless we know what you currently have on there, so post some pictures of it! (How much setback do you have and what is submerged volume of the flotation tank, if any?) All I can tell you is that on my Seafari shown below with original deck and transom, the waterline sitting at the dock is just below the bootstripe, which is about 5.5" above the chine at the transom, measured vertically. Now the Seafari has more weight forward than most CC models, unless you've moved your console, batteries, gas tank, etc., so it's a little more tolerant of heavy motors. It's just barely self bailing at the dock, with the waterline just below deck level. I normally just leave the plugs in or use Forum Member Fellowship's "Vortex" PVC check valve invention (last pic below) when diving when the deck's gonna be wet anyway.

Any idea on cost to get someone to reattach the cap and add the necessary changes to the transom? Can anyone recommend a fiberglass shop in the Charleston area? I've reached out to Bobby Ghelkin so far.