I will echo what Chris said....Milliput is not just for modeling. I used some to fix a leaky pipe temporarily until I could have if fixed properly.
Since it plugged the leak, I wasn't in too much of a hurry to pay to have it fixed and it was well over a year later when I did have it fixed.
When the plumber got done, he asked what I used to fix it with, and told him....he bought all 3 tubes of the Milliput I had....and has since come back to buy more.
New name for the business, Elm City Hobbies & Plumbing Supply! ;D ;D ;D