I'd head to a place like Home Depot and choose some type of silicone sealer
that's designed for clinging to smooth surfaces like tile, tubs or glass.
Since you'll need a lot, focus on the tubes that fit into a caulking gun.
I'd use sandpaper to rough up all the plastic surfaces, and then wipe them
clean with rubbing alcohol. First, apply the sealer to the top edge of the
box where it touches the lid. Give it a day to dry (no matter WHAT the
instructions say about how it cures in 4 hours). Then, flip the box upside
down and load the sealer heavily into the seam under the lip of the lid.

Make sure that kayak's tied to something on land, just in case...... :-)

"Norminn" wrote in message
...
I'm working on a project, using "something" plastic for a float on salt
water. Am contemplating using one of the low, rectangular plastic
storage containers if I can cement it closed to make it water-tight.
Don't know what kind of plastic they are typically made of -
polystyrene, polypropylene? Hubby and I like to engineer small,
inconsequential projects ) Trying to rig a small, floating platform
to store kayak out of the water. Any helpful suggestions appreciated.
Since it's almost Christmas, you're welcome to make fun, as well )