I have a 1981 nacra with several stress cracks in the gel coat. Some are from noticeable collisions, and some have no apparent cause asides from a fatty sitting on it. I WON'T be re gel coating the boat. But I don't want any more flexing or crackling when im on the decks. should I remove the decks and reinforce the bottom side of the deck topsides? How would I reinforce it? lightly sand and then a couple layers of mat and roving? What would you do?
I should clarify its not the gray decks that are cracked but the topsides of the hull the decks are mounted to. The pics convey the problem accurately.
Edited by joejedy on Apr 16, 2014 - 09:38 PM.
I would pull the decks, and add 2 layers of 9oz 0-90 fiberglass cloth to the the underside of the cracking. Cut the strips of cloth on a bias so the cloth is at a 45-45 angle when looking perpendicular to the deck/hull transition. Not sure if that makes sense, but by putting the cloth at a 45 degree angle you have more fibers running across the heavily loaded area.
Totally hear you on the bias part, it uses all the fibers instead of 50%. I have some heavier duty bias with mat on the underside. Any familiarity with deck removal and reinstall? I'll Google it too. Thanks!
In short no. Use heat and be gentle, eventually it should pop off.
Getting the decks off isn't too bad. The decks sit on top of the hulls with about 1/2 to 1" overlap. Use a sharp steel putty knife (or even a construction knife) and start working it in around the deck at the seem. Keep going around and round until you cut through all the thickened epoxy that is holding it on. There are a couple of stringer that go across but the decks shouldn't be glued to that. When you are done grind off the epoxy remnants and reattach using thickened epoxy (epoxy with colloidal silica in it).
Dave Bonin
1981 Nacra 5.2
Here are some photos of a tech album of what the inside of the hulls look like. It's from an old 5.2 that exploded.
http://www.thebeachcats.com/pictures/?g2_itemId=82844
Some are stuck on tighter than others. Do a search here, I think Airborne has a good album where he removed the decks.
I have a power tool that consists of a sort of oscillating 2" blade. Sort of like a very small pancake flipper that vibrates horizontally. That works very well for such a job, makes a nice clean seperation.
Mine is Canadian Tire, I think in the USA Harbour Freight has the same thing, only about $20 on sale.
Edited by Edchris177 on Apr 17, 2014 - 09:49 PM.
E C Hilliard
Nacra 5.7
Bombardier Invitation