Small screw holes in top of radiator...

So.. This dude put my fan shroud back on. With self tapping screws. Needless to say he drilled through my radiator. Aluminum on one side, and plastic on the other. Before I go buy a new one, I'd like to try some fixes.
First I tefloned a slightly larger screw. Believe it or not It lasted about a week. Then I got some putty from advance that you kneed together, and apply to the hole and surrounding areas. Its still leaking on the plastic side.
So... Any suggestions would be greatly appreciated. On a tight budget and it's a new radiator or diapers and formula. You know what I mean.
Help a brotha out! N

take it to a radiator shop but it would probably be cheaper to buy a new one.

3M panel bond sand paper and a patch. Glue it over the top. I used it once on a hole in my gas tank and it lasted for years. Just make sure it's clean dry a sand both parts. They have differs kinds. ABS plastic, metal ect.