Has this truck been painted before? Gas tank overspray, 87 K10.

[DanMcG]

Whats up with this seam sealer? Factory?

Yeap factory.

 

[Grit dog]

Old thread, but yes, factory

 

[Grit dog]

CFSJ mentioned the "factory peelers" in his post probably referring to the paint/primer compatibility problem
GM experienced in the 80's.
I had an '89 S-10 Blazer that the paint was peeling off of and in 1993 I was sent to the local Pontiac dealership
to be repainted for free.
The shop foreman told me they would use razor blades to scrape the old paint off and re-spray it... but only
from side body molding, up and over the top, to the side body molding on the other side.
Below the molding was not included in the recall.

That may have been the case with some, but back in the day, my GF had a S15 that was a peel and I got it repainted under warranty, they painted the whole thing.
And my 86 GMC, now, had a re-paint early on.
Looked like original paint at first, save for the same exact overspray on the fuel tank guards as the OP's truck. The entire truck except for the inside of the bed was re-painted. Doors and jambs were masked off to paint basically only what was visible with the doors closed. The original paint was still peeling on the door jambs, doors and rockers.
I found while prepping it, "most" of the original black primer was sanded off to bare metal. Only traces of it left under the new primer.
The new old primer was/is a color I've never seen before, tan/cardboard color. The tan primer bonded very well to the bare metal. The paint, presumably 30 years old ish, was not peeling anywhere save for a couple small spots on the lower doors and it held up to some up close pressure washing as well. However the majority of it too would peel off fairly easy with a razor knife. If I heated it up, it would come off in continuous ribbons, otherwise flake off if it was cold.
IMO it wasn't bonded well enough to allow any of it to stay. The lower body panels and the areas where the primary color was sprayed over the secondary color stripe bonded much better and maybe 5-10% of the truck wouldn't scrape off, but it was random, so whatever wouldn't scrape got sanded off.

Here's a couple pics, can see it just mostly came off in ribbons. The cab pic, the areas that aren't down to that tan primer and the big sanded spot ont he door were bonded well, the rest peeled like a banana.

Just adding this for others for reference as it was sort of a puzzle to me when I started on this truck.