U-tube it, get hints on how to use it, i did. Great stuff. Lots of good feed back too, however a lot of people stipulate stick to the instructions. I did and worked great. Por 15 has a putty in a tube almost like toothpaste and it goes very very hard, had to grind it to clean up. Filled some rust holes to perfection. Dont get the putty on your hands, it stays there for a week.
There is also another brand but similar stuff, advertises in Just Parts. Supposed to do the same as Por 15 but cheaper.