Dan Harrison <DHARRISN_at_hfcc.net> wrote: >>>>>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." <<<<< Yup! >>>>In glass or composit layups, the concern is that the fibers will begin to break down, and/or delaminate. Actually oilcanning in metal is far more likely to work harden the flexing area. Composite laminates are especially good at flexing repeatedly with less chance of failure than with most other materials. 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<<<<< I suspect you would find that either the patch failed (possibly due to being of an incompatible material or creating a stress riser that maybe oilcanning overflexed) or more likely a seam failed or the rudder or keel was sheared off leaving a big hole. Matt Broze http://www.marinerkayaks.com *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
This archive was generated by hypermail 2.4.0 : Thu Aug 21 2025 - 16:33:19 PDT