how are tanks held in place

The concentrated load of the 2x4 wedge caused the old tank to fail.
Make sure you don't create a point load on your FRP hull or your new
tank may survive at the expense of your boat. Ideally you want tank
brackets or straps anchored to existing strong points--bulkheads and
ribs the first choice. Lacking good radius, your longitudinals might
not have the strength for a big tank. If you decide to glass in new
transvers anchor points, spread the load. Build up a thickness of pad a
good six inches beyond the ends of your new support and carry pad and
bracket all the way to a longitudinal if possible. Good luck.

santacruz wrote:
 > I'm helping a friend replace a s/s under sole water tank with 2 new
 > ones. The old tank was held in place with 2 pieces of 2x4 that wedged
 > the tank against one bulkhead on the aft end and with the 2 pieces on
 > 2x4 wedged into another bulkhead on the fwd end- so the tank was held
 > in place longitudinally by only the end of the 2x4 - with the 2x4
 > positioned on the "hard" top edge of the tank where the welded edge
 > was. Eventually the welds cracked from the concentrated pressure of
 > the 2x4, and the tank leaked.
 >
 > So how to hold the new ones - it's about 9" to the bulkhead in front.
 > The tanks lie about 3" above the FRP hull.
 >
 >
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