Hot Rods model a rain gutter replacement metal prep

Hey guys just spent an hour searching and suggestions are varied on this. I'm replacing the gutters on my 30 coupe and am unsure the best way so seal the metal in between. I am going to blast the area where the gutter will be and sand it. The big question is how to properly seal the metal before I weld the new gutter on. Just weld thru primer? Or should I paint it as well? I even saw some guys using seam sealer as well. I had always thought that primer was not a sealer and I do not want rust forming in between eventually. What do you guys suggest? Thanks mike

 

epoxy primer or primer and paint and I like the idea of a proper automotive seam sealer. (jut primer will let moisture through)

 

Just weld through primer. It is made to melt and reseal with the welding process. Paint ( as well as rust converters, sealers, etc.) will just burn off, leaving no protection. Primer and paint protects after putting the gutters on. You can use a seam sealer to fill the seam, if you spot weld the gutter on, not weld it solid. The sealer will flex with the open joint, instead of cracking, like filler, or just paint will.

 

yep he got it, I missed the "weld" bit, I have Model A (and nails) on the brain at the moment.