Shower Remodel, Weekend 6

I'm a little behind on the shower updates.  This picture is from the weekend after TALE - so that would be March 9th or so.  Basically this part consisted of painting on the waterproofing material.  It's really like thick paint so I was able to roll or brush it on.  I also used a reinforcing fabric in the corners along the shower pan to prevent any cracking at the joint.  The other joints all have fiberglass tape in the thinset so they should be fine. 

After everything dries, the goal is to do a flood test.  The flood test consists of plugging the drain and filling the shower pan with some water to make sure it doesn't leak...for 72 hours.  Sounds simple in principle, but I'm out of ideas on how to plug the drain.  One online article recommended using a balloon.  That worked for about 18 hours before it shifted and I lost some water.  A second attempt didn't even get that far.  The other plugs I've tried didn't seal for more than a few minutes so I'm still working on the flood test part.  At least I have a successful 18 hours test!