[78w72]

i did a search for this but only came up with conflicting info.

i have some rust scale & pitting in the lower corner of the front windshield channel of a 2nd gen firebird. im having the windshield replaced & would like to confirm what the best coating is to use in that area. i will be using a 3m urethane sealant for installing the glass. so what is the best paint or primer to use in the channel after i clean up the rust?

ive read a few threads here about this & some say to use por15, others say to never use that under glass urethane sealant. some say use the rust converter primer stuff, others say its too weak to adhere to the surface. & many others say use a epoxy primer or self etching primer. anyone know for sure whats best to use in this situation?

also, after wire wheeling the area there are a few small pinholes, should they be treated with a rust converter &/or filled with a body filler? this car will rarely get wet & will be a garage queen so im just looking for any tips on the best way to address this issue? thanks.

[Toms bird]

The best thing is remove the rust sanding grinding or welding in new metal. Urethane primer sticks best to 2 part or epoxy primers. I do believe you can top coat por 15 when it's still tacky , then you can have the best of both worlds por under and correct primer on top. Keep in mind your trying to meet the standards of cars with airbags. You really dont need to do that. The urethane manufacture also tells you to sand a bond area that has been painted, then use the appropriate primers, like if you were doing a quarter glass or back glass area . Personally I would do my own car like this I like the idea of paint protecting and holding back rust. It's really a toss up as to what your gaining. Leaving it in primer will the rust come back and weaken the bond. Using different products and have adhesion failure. Doing things that are defend able in a court of law and what we do to our own cars to get them to last as long as they can are two different things.
So on my own car for the record and short version. Get metal as rust free as I can. If needed treat with phosphoric acid limit contact to only areas that need it. Depending on severity use por 15 only on area that need it . Put 2 part primer on top of when por is still tacky (read directions I'm going from memory) and any bare metal. I would leave a small enough strip on the 2 part primer bare for urethane contact 1/2 inch or so then paint the rest of pinchweld. Let it cure fully before putting in glass after lightly sanding and using manufactures primers.