I have a door off of a Trans Am that I want to put on my Firebird. There are several small holes in the panel from where I removed the ground effects. Are these large enough to need welded? Can I fill them with body filler, and if so, does it have to be waterproof/fiberglass filler?

 

theres only one way to make it the right way. weld it

 

tap or grind then weld and grind some more and use lightweight filler or cream to smooth it down perfect