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Old 09-04-2009
Wiley1 Wiley1 is offline
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If a boat is pulled too green from a mold it not uncommon for some weird changes in shape to occur. I've seen small FG lapstrakes with almost offset "planks" as a result of being pulled too green (ie: to early, before the resin has fully set up/cured). It can also happen when the initial layup separates from the mold and becomes able to move and adjusts to stresses as it cures. If that's the cause then you should be able to take a flexible batten and lay it over the area in contact with the hull. If the ripples are all away from the batten (the batten forming a smooth curve with the ripples as dips away) then I would initially suspect a separation when molding. Regardless of the cause, when this happens there is then the question of what to do. Simply toss several thousands of dollars of materials and time for what is basically a cosmetic problem or what?

You are right to be concerned, if it is a solid layup you can try scratching your fingernails over the area and the areas surrounding. Often separations will be detected by a distinct change in sound as the space created by the separation acts as a resonator. This works as well to detect voids in decks etc. where the vacuum bagging or whatever failed to force intimate contact between the outer layers and the core.

Since it is a solid layup you can also try trans-luminescence which is a big word simply meaning shine a light thru the hull. Damaged areas, separation, bruising and delamination will show up as darker areas. Depending upon the amount of veil coat (some boats don't even have a veil coat) you will need a powerful light and to remove the bottom paint to the plastic. Before scraping off the bottom paint I would try shining the light above the waterline to see what sort of transluminesce you get for that hull. If there is a heavy veil coat you might not get much. The navy used to require that all boats built for them in FG were layed up without gelcoat so that they could inspect the layup for bubbles, voids and unsaturated mat, roving, cloth etc all of which show up as dark or black spots or areas. Hand held million plus candlepower lights being readily available make this an easier proposition than it used to be. Also you can check with the manufacturer if they are still in business. If it was pulled green or separated from the mold and the ripples are as a result they might have a record of that (and that they had to reduce the price of the boat as a result for cosmetic reasons.)

I hope this helps. Keep us posted as to what you find.

Bests,
Wiley
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