I'm
not aware of any extra-long sink mounting clips. You might try
calling some local lumberyards, many of them have kitchen-and-bath
departments and can get special hardware.
But I wouldn't be surprised if
you came up empty-handed.
I've experienced this problem
before, though the short-coming of the fastener was not as much.
My solution was to RAISE the
surface of the wood, that is, to mill a pocket in the underside of
the wood counter-top. I used a spade drill bit, probably 3/4"
diameter or so, and drilled part way into the underside of the
counter, just beside the sink opening. Since the spade bit left a
mostly-flat-bottomed hole, I simply had to chisel out a chunk of
particle board to get a flat pocket for the sink clip to grab on
to. This will only work if you have 1/2 inch or more of wood
thickness to work with.
Bruce W. Maki, Editor.