Cracks and structure question

[MacGyver]

My 19 is a 1989 model,
I have some structure cracks in the gelcoat that extend slightly into the fiberglass. I have ground them out but I know this has to be a problem with the entrance into the boat, the companionway.
These cracks are located just below the hatch board drop stop...

What I think this is from is maybe the support of that extension there, being it is only pieces of 2x4's there underneath.

I am wondering if this is that way on future models.
I am planning to maybe stiffen this up and change the bilge board to alleviate it. It will work well with my wiring project anyway..... You can see movement of the step inside the boat when putting weight in this area, which is the only thing I can relate to it....

Anyway, pictures if you have them of the under section, so I can compare em to mine if you can.

Thanks!
Mac

[Salty19]

I'm not sure what 2x4's you are referring to.  Are you saying the area under the removable companionway board, behind the step?
Shouldn't be any 2x4's there?  I'm pretty sure they were all built with just fiberglass under the steps up the edge of the bildgeboard. Then foam aft of that board, the foam setting in a box made of plywood.  There might be some ply bedded in the glass up by the hatch, but I don't recall any wood, certainly not something 2x4.

Could be a prior owner modification?  I dunno..let's hear what the others have to say.

[MacGyver]

It is right behind the top plate that the stair hinge is, that switch panel mounts into that board, and that board is tied into 2 (right and left) 2x4 pieces, about 6 inches long or so, glassed in (but not completely) to the surrounding glass which would be the underneath of the area on the outside below that drop stop.

Any chance you have a pic of that area Salty on yours?     I might just run out there and snap a pic of mine......

odd thing to describe.

Mac

[MacGyver]

Took some pictures.
Here is the damage all drilled out, each pathway was a crack I chased out.


Here is what it looks like inside


And here is another picture showing the tab in of glass to the 2x4 piece


Now what I am thinking is to extend it down to the bilge sides and remake the bilge board, and the sides would then attach to the bunk sides.
Not something I planned on doing.... but I will if it is needed to keep those cracks from coming back.
From what I can tell, then I step into the area and sit, or step onto the companion way, etc (which is popular for us to do, from time to time) the step moves forward around a 3/8 inch, maybe even half inch....

This movement over the life of the boat is what I think has caused them, they were there already when I bought the boat.

Anyway, what do you all have inside yours? The same? Different?
And if it is different, any chance I could get pictures from you of it?

Mac

[brackish]

Stop worrying Mac.  Gel coat cracks occur because of stress, strain or simply differential expansion.  They are not a sign of structural damage and do not lead to it.  If it makes you feel any better, my 2005 23 has the same gel coat hairline cracks in the same area.  It is obviously an area that because of the layup geometry has some differential expansion issues.   The underlying fiberglass is reinforced, the gelcoat isn't. Often, repairs don't last any longer than the original.

[Lafayette Bruce]

Mac
Structurally my 19 is made the same (1985).  Mine does not have the course woven fiberglass is that area.
Pictures are great, ain't they?
Lafayette Bruce

[MacGyver]

Brackish, worrying is my middle name, oh.... well, kinda.
I make my wife mad researching, etc, but in the end she is always happy with the end product.

My main reason for asking was to see if there was a addition to alleviate the problem later down the line, it isnt a big deal, but I am adding wiring in that area, so if I modify stuff there, and add a support, I really only want to do that one time, so if They made a change, I would want to incorporate it into the design therefore killing 2 birds with one stone so to speak.

I understand that gelcoat does that, but that is also a sign of things moving a little more than needed, so alleviating it will keep it from ruining the paint job I am putting down now, I will be happier with the end product.

It also doesnt help, I am extremely picky........... (sometimes too picky)....... but it makes me a excellent repair guy for the serious Sailboat racers boats.    Those guys put me to shame......  (one guy last week was waxing his mast...... for sheer speed..... seriously....)

Bruce, Pictures do help immensely, I am guessing on yours they did just normal glass?

Mac

[Lafayette Bruce]

Yup, Just normal glass.
Lafayette Bruce