On Sat, 17 May 2008 14:01:41 -0400, cj wrote:

greetings, i am planning on making a small table for our deck and i
would like to use a mosaic tile pattern for the table top so i thought
that i would make a pan out of 16 ga., turn it up side down and tack it
to the inside of the table frame, therefore giving me a flat surface to
put the tile in, and keep it flush with the top of the frame. now i am
wondering what kind of adhesive would work best to affix the tile(3/4
inch tiles sheets with a mesh backing) to the 16 ga. the frame will be
made if 3/4 square tubing that i will have powdercoated

any comments would be appreciated,cj

I have to agree with the majority - you don't want the bottom layer
of an outside table to be a steel pan. It's going to collect all the
spills and rainwater and rust out in a big hurry.

I would use two layers of cement backer-board held together with
construction adhesive - make the two sheets to fit the table, put the
bottom one on a dead flat surface, place adhesive between the two
sheets (even pattern of big caulking gun beads on the bottom sheet),
place the top sheet on top and get them lined up, then clamp them
together with a great big pile of concrete blocks for the glue to cure
for two or three days.

The table top really doesn't need to be fastened to the steel frame,
gravity will do most of the work - you could glue it in with a thin
bead of adhesive where it sits on the frame, as long as you can get in
with a shop knife to cut the bond loose. You want to be able to take
it apart easily, because the steel will need painting every few years.

Then you can drop the cured backer into the table frame and finish
it by tiling with mastic tile adhesive - you can use thin-set mortar,
but the odds are higher that it will come apart and need reworking
after a few years. Any flexing and thin-set will crumble, where a
mastic adhesive bond will give a little.

And grout the tiles to finish.

This way when (not if) it gets wet the water that gets past the
grout or the caulking around the edges won't collect in the table top
'sandwich', the water will drain through and the backerboard will dry
out in the sun.

-- Bruce --