Working on my daily driver / project car a 1991 honda accord 4 door se.

Got it running good and it all started with a quest for a dry trunk. I have had a small leak due to bad trim seals and tail light seals. I just replaced them, the leak is less now, but reviled other leaks due to body rust...
My experience and research

Fiberglass
I used fiberglass (think tiger hair, polyester resin) and bondo growing up.
Research says:
epoxy resin is better, stronger, less shrinkage, bonds better to metal.
Only usable with fiberglass mat there is no can product like tiger hair that’s putty easy to spread. ( is this true?)

Epoxy putty
Found this looking in to epoxy resin. Por-15 sells some. Not sure if its worth anything yet.

Welding
I have used stick welder for 1 class, very little experience.
Research says
This is the right way to do it, cut out replace. Hard with cheap welder, easy to blow through sheet metal.
Maybe can come up with wire no gas or stick welder talking 120v 125 amp or 80amp harbor harbor freight

Damaged area:
Rear wheel well (not causing leak just cosmetic atm)
Trunk lip ( where weather strip sits to seal the trunk lid)
Trunk lip ( seam sealer cracked missing upper edger by window)
Rear end corner (rusted on lower left of right tail light)
Rear end corner (Seam joint where rear fender? Meets rear of car at tail light)
Trunk floor rusted at seam sealer / glue from leaks.

Questions:
Was the trunk floor glued or welded?

Can I just clean up the trunk lip use some chopped fiberglass and polyester resin aka bondo glass etc?

Trunk lip seam sealer, is that seam sealer in corner by window? Can I just sand reapply or use fiberglass?

Does any of the damage look to be structural?

Pulled up some of the glue or seam sealer it looks rough.

I bit overwhelmed, I need to stop the water leak to stop the rust, but I need to fix the rust to stop the water leak.
Noob at body work here.

It seems first step would be to remove rust, clean then neutralize area if I cant get it all or missed some microscopic rust. Then repair and or prime.
I don’t care what it looks like, just would like to get another 4-5 years out the car. Trying to find a cheap prime/paint to use. I know its best to use epoxy but can’t find it cheap, and I’m trying to limit it rattle cans. Looking for good system to use from Walmart / homedepo / autoparts store. That way I know all the primer/paint/clear will be compatibly.

Please advise.

 

I took an hour with the tools I had, and worked on the worst part. here is what im looking like. (seems, im going to need to get a smaller grinder to get in by the tail light.)

for some reason my cell phone is not taking photo of what the eye is seeing, its adding a rust color lol.

its all fresh metal, with a rust pit here and there, not to sure how to get under the crack that has been created.

top side / under side.