[Paddlewise] Oilcanning

I would have thought someone else would have covered this by now, but a reader (I forget who), asked for a definition of "oilcanning," so here goes:
Remember Grampa's old oilcan, with the rounded body, a pointy nozzle, and a bottom that you pressed with your thumb to make it flex?  By flexing between concave and convex, it pumped oil. 
A hull that flexes that way is said to be "oilcanning."   In glassor composit layups, the concern is that the fibers will begin to break down, and/or delaminate.
True story:  A dozen years ago, I sailor I know had his 35' sloop parked on a cradle in his back yard over the winter.  During an ice storm, a massive branch broke off and spiked the hull straight through.  If it had been a vampire, it would have been dead on the spot.  As it turned out, that took a bit longer.
He had the hole professionally patched, but in the next year's Port Huron-Mackinac race, the seas were amongst the highest in years.  Suddenly, the boat began to take on water.  The crew barely had time to deploy the liferafts and send a mayday.  They watched as she went down, with all her lights still on.
The mayday call was heard by some other friends of mine, who used the LORAN coordinates to find the crew. They had to abandon the race to perform the rescue, but were given a special citation for sportsmanship.  
The owner swears the hull was sound, but I suspect that if you went down 200' or so in Lake Huron, you'd find that oilcanning was the death of her.
Dan Harrison


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