Before the roads in NY turn to salt beds, I need to undercoat the bottom (thinking of just using spray on) and atleast do something with the bottom of the doors and fenders. I like some of the 2 tone paints that have been done on here. I was thinking of going 3 inches around the bottom. But I was wondering, after looking around a bit, what would be the best to use on the body, undercoating or bedliner? I have already fixed rust holes on each wheel well with fiberglass/bondo which is covered in primer right now. Thanks for any help.

 

Personally I would use a bed liner because it gets hard. Most undercoats stay soft, or rubberized I think is the correct term. Boxliner is also tintable if you want it to match your truck.

Remember primer is not a sealer...water can go through it.

 

Bed liner for sure, my whole cab, hood, and fenders is coated in it, and I'm not afraid of WI salt at all this winter.