Crack help

M

mpmccoy

New member
No I'm not on drugs. I have a few cracks that I need help with. The first one showed up last season and I monitored it's behavior this season.
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The thing that has me scratching my head is that where the bulkhead meets the hull it's caulked with a flexible sealer and then gel coat was applied over top. This caused the gelcoat to flake off during hull flexing. Part of the seam is glassed. The large crack I'm assuming is becuase of too much flex possibly caused by the lack of glass and resin? This isn't the only place on the boat I've found gel coat over sealer and it's flaking off too!
When under way the flexing of the hull causes a snapping sound but can be controlled by finding a "happy" frequency. When I put my hand in the cubby hole in front of the mates seat I can feel the bulkhead and deck move with respect to each other. I can't tell if both or one is moving because my fingers don't have a reference. Has anybody seen or experience a rupture at this point? Have any suggestions?

The second crack showed up this season. I found it when I took the v-birth cushion out.
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The gelcoat is separated from the glass. There are no marks on the outside of the hull.
 
I went to your album to look at the full size photos. Both of these areas are places where secondary components are "tabbed" into the hull with fiberglass tape (or should be fiberglass tape). Actually the best way of doing this is a layer of 1.5 oz mat and then a layer of 6 oz tape. Many times 3rd and 4th layers are applied. Each layer is narrower (or wider) than the other, so spread the load out over the hull, and avoid a "hard spot. Also there should be a fillet at this place--again to avoid a hard spot. The Fillet is filling and is a cove which allows a nice radius of the cloth tape and mat.

Now what was done in your boat? The first crack is at the joint between the floor/hull side and the bottom of the bunk and porti potty platform. (this piece of the platform and bunk should have been molded in one piece) There should have been ONLY tabbing--no sealant at this joint. This should form part of the "box section" of the foreward part of the boat, which does stiffen up the hull. The balsa core, the sides of the boat, and the shoe box fit of the top which is glassed in at the hull to deck joint are also areas which strengthen the boat. The bulkhead between the fwd cabin and the deck, sides of the boat, flats and is not a structural component.

What needs to be done--any material which is a sealant needs to be cleaned out. The glass needs to be very lightly ground, just enough to present a fresh surface (get rid of the interior spakled coating) then build up a propper tabbing using first a layer of mat, then cloth, then mat and cloth (for polyester resin). If you elect to use epoxy (which I would) then you can just use the cloth in 3 layers (concentric widths). Then you will have to find some of the finishing "paint" and cosmetically finish this area. I would not attempt to gel coat it personally, but that can be done if you used polyester (there are tie coats which will allow gel coat with epoxy).

The area of the bunki is a similar problem--and if you look carefully, there may be some other areas where there is loosening of the tabbing. Now why did the tabbing come loose? The bunk platform is put in after the hull is popped from the mold, and perhaps even after the hull to deck was applied (the older boats had some components and the deck place don with the boat in the mold). I can only speculate that either that area was not properly cleaned, or that there was still some wax in the laminating resin (common problem with secondary bonding) or that the first coat was not properly catalized. My guess is wax or debris. Either way, you have to re-establish this tabbing. I would pry out the layers, grind down back to clean glass, and make a new tabbing, as above. However, you do need to look at the other areas along the V berth, and using a coin or back of a screw driver, tap out (sounding) the rest of that laminate, to see if there is any delamination. I might tend to replace all of the tabbing of the bunk.

Again, this is a bit of a stress area. The bunk platform is rigid, and the hull will flex, thus working any potential defect in the glassing process loose.

Sorry to see the problem--the fix is relitatively simple and in-expensive--but apparently warantee no longer applies (unfortunately). I would personally go to my dealer and discuss this with him.
 
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