Recently I had an owner spend about $2000 prettying up an old 19 foot fishing
boat. Upon initial inspection
, I told him the decks were soft, the condition of the stringers and fuel tank
was unknown, the motor
was antiquated etc etc but he had fallen in love with the idea of fixing it up. He thought the decks were "functional." He had paid $1500 for the boat, trailer and an old "Tower of Power" 150 Merc.
The first thing I did was pull off the captain's pedestal
chairs and drill a big (5/16") hole in the deck under the chair which was an area of concern for water
penetration. The wood shavings that came up weren't wet, but the wood was somewhat softer than expected and dark in color. I showed the owner the results and again tried to get him to sell the trailer and motor
to cut his losses. He said he could see up inside the boat's bilge
near the transom and could tell some work had been done but thought the boat was solid. Note that he had described the boat as being in "good mechanical condition, as he had been restoring it with his sons." It had been stored under a shed for FOUR months (very important later.)
Started doing body work on the boat to paint
it, and there were acres of resin-starved fiberglass
along the mold
edges that the owner thought were usual wear patina (chips.) When hit with a dremel they just exploded and got bigger. Lots of filler. More advisories about ending up with $10,000 in a $4000 boat...
Pulled the console off next. The filler hose to the fuel tank
was completely broken down at the hose clamps, so that as the gas tank was filled, gas would leak out into the foam surrounding the gas tank (not the proper way to bed
a gas tank as it traps moisture against the aluminum
tank.) Molotov cocktail!
To replace the fuel
hoses, it was necessary to cut into the deck between the tank and the gunwale. Using an angle grinder, I cut the upper fiberglass
skin and removed a 12 inch by 18 inch section. This exposed the core, which consisted not of dried-out water-damaged marine plywood
but instead SOAKING WET (after at least four months of dry storage!) two inch wide wood planks laid side by side, which could be removed with a spoon. This area was not even "boingy" although it did fail the "screwdriver handle percussion test." In addition, the fuel
tank vent hose could now be examined and the connection to the vent outside the hull
had completely broken off due to corrosion
so that fumes were being vented into the closed space between the outer hull
and inner liner.
At this point the owner sold the motor and the trailer for $1500, paid me $2000 thereby losing only $2000 of his $3500 investment and dumped the project
The main lesson from this saga is the only way to tell the condition of deck coring for certain is to do destructive testing. And in this case, even drilling a big hole in the worst location didn't adequately reveal the extent of the water
infiltration and damage. Once organic core material has been exposed to water infiltration, the laminate will almost certainly delaminate and lose its structural integrity. It will not be "OK" even if it dries out, which could take years after preventive measures are instituted.