POR 15 says there kit will fix it.....? Any one use this stuff.....??
Think of POR15 as hard paint. Good to paint over bad looking rusty metal. By the way, it will break down if exposed to UV light. You need to top coat it in order to save it from breaking down in the sun.
You should tear down the areas you want to do the patch work on. This involves cutting out the rusty metal. Once you have all the bad stuff removed then evaluate what panel/patch, 1/4, 1/2, full panel. If your going to replace a lot of sheet metal on your floor then your better of getting the entire floor pan. They have a good body panel that extends from the front toe panel to the rear floor pan. This will save you a lot of time and ensure your body is straight. Most of the welds are done for you.
If you don't have many tools and plan to learn welding and do you own car then budget for $$ for good tools. The best way to save money is to save time. Buying no tools and cheap body panels are a receipt for disaster. If your not willing to invest in tools then I suggest you get someone to weld them in for you.