impending structural failure?

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impending structural failure?

Post by incoming »

I was changing the impeller on my port engine and noticed this cracking where the stringer is glassed to the hull (right in the center of the image):

Image

Is this likely just sloppy work or does it look like the stringer could be completely delaminating from the hull? It's not an area I go into often so it may have been like this since i bought the boat a year and a half ago, no idea when or how it happened.

Any thoughts on how serious this is?
1985 Bertram 38 / 2002 6CTA 480CE's
Yannis
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Re: impending structural failure?

Post by Yannis »

I had the same in two areas:

The first was just over the struts, around the strut-pads in the bilge. I made a flimsy correction by adding one or two layers of cloth impregnated in resin. Looks ok, but when I will remove my engines to scrape and paint them in two years from now, I will inspect the bilge thoroughly again and re-fix this too.

The second was under the dinette, where the main bulkhead meets over the stringer and the hull just below. I had my grp guy sand it and fix it with a few layers of cloth impregnated in resin. Every year before splashing I stick my head down there to see if it holds and...it does so far, so no further concerns. Im pretty sure I myself ! did this during the first season or two, when I was thinking I had bought Mc Guivers’ ride and was acting as a stuntman of the seas...I relaxed since!

My advice is that you should fix it so that you bring it to a structurally perfect condition, but also, because it may allow water into the stringer itself, which then, should become a bigger concern.
The way I see it in the pic though, it seems rather insignificant but requires care so it doesn't get worse.

Good luck.
1973 B28 FBC/2007 4LHA STP's - "Phantom Duck" - Hull "BER 00794 1172"
Tony Meola
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Re: impending structural failure?

Post by Tony Meola »

Unfortunately I can not see the picture. All I get is big white dash in a grey round circle.
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Carl
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Re: impending structural failure?

Post by Carl »

Tony Meola wrote:Unfortunately I can not see the picture. All I get is big white dash in a grey round circle.

Tony- - your one step better then me. I only get "image" where the picture is supposed to be.
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ranjr13
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Re: impending structural failure?

Post by ranjr13 »

Yea, no pic - just "dash".
Bob Norton Jr.
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Re: impending structural failure?

Post by incoming »

that's strange. i'm using google to host. i'll try another hosting service and see if that fixes it. anyone have any suggestions of hosts that consistently work with this site?
1985 Bertram 38 / 2002 6CTA 480CE's
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Re: impending structural failure?

Post by incoming »

is this any better?

Image
1985 Bertram 38 / 2002 6CTA 480CE's
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PeterPalmieri
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Re: impending structural failure?

Post by PeterPalmieri »

I can see both images. Looks to me like that isn't from the original build. To me that could mean two things either someone added that and didn't do good work or there is an existing problem underneath that they tried to address unsuccessfully. Of course I could be wrong and it is original
1969 31 Bertram FBC "East Wind" hull #315939
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Re: impending structural failure?

Post by incoming »

only thing i can think of is that the stringers may have been "trimmed" when the new engines were put in (hull is 1985, engines are 2002), and the metal longitudinal stringers were put it in to support the new motors.
1985 Bertram 38 / 2002 6CTA 480CE's
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Carl
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Re: impending structural failure?

Post by Carl »

Yes sir, can see this picture now.


I'm thinking along the lines of Pete.

Looks like someone added a layer HD Woven Roven for whatever reason and the ends didn't quite bond.
Could have been to re-enforce, fix, build up, cap the top or...

You said they did new motors...maybe to re-enforce?
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MikeD@Lightningshack
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Re: impending structural failure?

Post by MikeD@Lightningshack »

Stringers normally run longitudinal.

That appears to be a support bracker that was tabbed to the hull. If it is not supporting anything anymore you could just cut it out. Or fix it with a grinder, epoxy and sone cloth. If it is not supporting anything, there is no rush.

Bertram factory structural layups did't look like that. If it was meant for structure they would have tied it into the stringer. The factory did not leave open ends on vertical structural layups. They folded everything over nice and neat so it was water tight. You might see that kind of open layup for chocks or cabin structures, but not on the structural stringers.

This was probably meant to hold something up. Maybe batteries, engine componenets or a genset.

The hulls flex so much that even factory tabbing came loose in my boat. I replaced the entire birth bulkhead and super structure and found several tabs delaminating. It is really only a problem if the item being tabbed is loaded and starting to rub or push against the hull creating a wear spot.

There were no brackets like what you show between stringers on my Bertram. If you hunt around you will likily find other tabbing delaminaring, especially in the birth. Unless it has let something come so loose that it is rubbing on the hull, I wouldn't worry, and I'd correct at a convenient time.

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MikeD@Lightningshack
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Re: impending structural failure?

Post by MikeD@Lightningshack »

FYI... that big round notch in the stringer further back in the picture would be far more concerning to me, assuming it was not properly sealed aftet it was cut. That is an actual stringer and I would not want water intruding that lumber. The glass maybe thick enough without the lumber, but I would make sure that it was sealed as soon as possible if not already. Can't tell from picture, but it is clearly a notch cut in a stringer and it looks like it was done post construction.
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ktm_2000
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Re: impending structural failure?

Post by ktm_2000 »

Can you take more pics from further back so a bigger perspective can be had of the area in question?
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Re: impending structural failure?

Post by incoming »

Apologize for being sloppy with the wording. The structure I was asking about is probably more accurately referred to as a "rib," not a "stringer."

Below is a pic of one of the "ribs" on the other side of the hull for context (and part of a second just barely visible in the bottom left corner). There really isn't anything mounted to them in terms of accessories or secondary structure. There's one glassed to the hull every ~3 feet, presumably for stiffening. I found it odd that they weren't glassed to the stringer as well.

The longitudinal structure shown in the top picture is a u-shaped steel beam that was bolted over the top of the stringer, presumably when the new cummins motors were installed in 2002.

Image
1985 Bertram 38 / 2002 6CTA 480CE's
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JP Dalik
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Re: impending structural failure?

Post by JP Dalik »

Looks like old fire suppression brackets that were glassed to the hull for support I can only see the last image but if the other side is he same and not used for fire suppression bottles you could just cut them out. There are no ribs in a glass hull and only stringers and bulkheads. The last image is neither stinger not bulkhead.
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