I think you actually caught the issue, believe this was just really cheap filler I bought at Canadian tire, or maybe even a local home hardware. Never even thought there was different qualities of filler - Oh, to be young again.
Thank you for this.
Took my 71 down to bare metal with wire wheel and 5” angle grinder, used sand blaster for small areas that I couldn’t get with the angle grinder. Used endura primer and paint…I’m not too sure what we did wrong, the finish only last about 4 years in the places where we welded, 18 years later it...