I want to tile a fountain.

[SJ56]

A friend put an old cast iron bathtub in the ground to make a fountain. She spray painted it and it looked great! That is, until the paint started to peel off everywhere! I suggested that she try to tile it using tile, glass or pottery pieces. I have seen it done indoors, but how would it work for a fountain? Since the metal tub will expand and contract with heat and cold, is there something that would work? Thanks, SJ56

[pushkins]

You have a multitude of problems:
1: enamel tub
2: peeling paint
3: outdoor exposure

If you can remove all the peeling paint back to some sort of stable surface, you could use a waterproof builders adhesive applied to the back of each tile and pressed into place. It will need to be waterproof as it's going to be submerged, anything else will eventually fail.
Grouting is going to be your next HUGE hurdle, about the only thing I can think that you could use in these sets of circumstances is that expandable spray grout that is used on pre glued tile floors. Any normal grout WILL crack and fall out as the metal tub expands and contracts.

Both of the above products are available at the big box stores.

[HayZee518]

the porcelain coating on a cast iron tub is vitrified. that is, the coating is fired on as if it were a piece of pottery or a clay dish. you'll need to really scuff up the surface for "teeth" for the adhesive to grip. As Pushkins says use a waterproof adhesive buttered on each tile. A bathtub non hardening but waterproof grout or sealant in a tube may be the only option to fill in the spaces between tiles. check out the D.A.P. company's web site. DAP makes putty like for windows.