On Fri, 12 Sep 2014 12:01:39 -0400, Ed Pawlowski wrote:

On 9/12/2014 8:53 AM, Mayayana wrote:
I'm wondering how you have hairline cracks that
don't leak. Is it possible that they're just deep
scratches? If they're really cracks then it's time
to remodel the bathroom. One doesn't just glue
bathtubs together. If water gets through that you
don't know about you could eventually be faced
with a bigger job than the tub: Replacing the floor
joists and the ceiling below.

That was my thought also. Cracks never seem to stop unless drilled so
it will only get worse.

Do you use the tub for baths? If so, replace it, but if not, you can
buy a shower pan the same size and have a really nice walk in shower. I
did one bathroom last year and the second is being tiled as I write this.
This is what I used
http://www.swanstone.com/index.php?prod=383
I suspect it is crazing feom flexing. Usually has to get pretty bad
before it leaks, but don't leave water standing in the tub for days!!!

When I install a "plastic" tub I make sure it is well supported. Last
one I did I put high density foam board under the tub then sprayed
itin with high density urethane foam. Salid as a cast iron tub. No
flex at all.