Epoxy or weld-through primer?

[old soul]

I know this has been discussed before but here it goes anyway. I will be installing a new inner and outer bed side panel on a '99 F-250 (longbed). The inner panel attaches to the bed floor with a pinch weld, like a rocker panel. I will be plug welding this pinch weld with the welds about 1 3/4 inches apart like the factory did. There will be about 50 welds just on the pinchweld. Should I use epoxy or weld-through primer on the pinch-weld flanges prior to assembly? I prefer epoxy but the welds are so close together I think most of it might burn off. I also don't think the weld-through primer will offer much corrosion protection as it will be subjected to what ever the truck is used for, whether hauling dirt, fertilizer, or four-wheeling through mud holes. The seam will be sealed on top but the flange (pinchweld) on the bottom will not be sealed, other than epoxy on the outside.

By the way, not interested in using adhesives.

 

[Bob Hollinshead]

no epoxy or weld through primer before welding. Strip the flange of any paint, rust, or primer so you have nice clean metal. Weld the panel on. Grind your welds if needed. Tape off the bottom of the seam and poor epoxy primed in from the topside and let it set for a day or two. The masking tape will hold the primer in the seam-tape it well. Remove the tape after the epoxy lock up. Clean any excess off on the exterior that isn't needed, prime the exterior and then apply a good quality urethane seamsealer or epoxy seam sealer-then paint. It will last forever.

 

[LostMy65]

no epoxy or weld through primer before welding. Strip the flange of any paint, rust, or primer so you have nice clean metal. Weld the panel on. Grind your welds if needed. Tape off the bottom of the seam and poor epoxy primed in from the topside and let it set for a day or two. The masking tape will hold the primer in the seam-tape it well. Remove the tape after the epoxy lock up. Clean any excess off on the exterior that isn't needed, prime the exterior and then apply a good quality urethane seamsealer or epoxy seam sealer-then paint. It will last forever.

Great Post!
Thank you!

I'm doing my rockers in the coming weeks.

 

[old soul]

Simple, efficient, and durable. Wow. Thanks, Bob, for giving me a solution to a problem that has been nagging me for a couple weeks. I'm sure I will use this technique in the future also. Much appreciated.