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Hammer Diagnosis
Judicious Use of a Hammer Can Find Unseen Problems

Replacing the Stringers in a 1988 Sea Ray


Sometimes, damage to the hull is not as obvious as a gaping hole in the freeboard.  That’s when a hammer becomes a useful diagnostic tool.  Structural wood in the hull of some boats can rot when water seeps through microscopic cracks and holes in the fiberglass that covers them.  Stringers are a case in point.


Stringers, for those who aren’t sure, are the wooden sleepers like small railroad ties that the engine(s) are bolted to.  Often they are set on the inside of the outer hull and covered with the fiberglass of the inner hull before the engines are bolted down.  When these rot, boat owners may not even notice until the engine starts wobbling and the bolts and brackets come loose.  The sound a hammer makes when it taps on the fiberglass that surrounds the wood can indicate that there’s rot underneath and the stringers can no longer do their job.  The hammer makes a dull thud rather than a sharp tap.


Enclosed structural wood may also be used in the transom, under seats are other heavy interior pieces that need to be firmly bolted down and supported over an area larger than a bolt and bracket.  These are also susceptible to rot that is rarely noticed until it’s too late.


Herman Bolger of Offshore Group in Amherstburg has seen this problem come up often.  “A good surveyor will find rotten wood in the hull with a moisture meter and it’s something you should know about before you buy a boat.”  Unfortunately, too many buyers are misled by the honest face of the seller, who may not even be aware of the problem.  Once the deal is done the rot becomes the responsibility of the new owner, rather than something negotiated between the buyer and the seller.  One very good reason to be sure you hire a marine surveyor before you sign.


Repairing stringers and such is not often a hugely expensive fix but you can make a mistake by going the cheap way.  It might come back and bite you.  Get it done right… by good people like Offshore Group… and you’ll get a lot more pleasure out of your boat… for a lot more boating seasons.

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