I have painted numerous cars in my life, and dont simply say things to satisfy people. So, like I said, top coats (paints, clears) and undercoats (primers) are not designed to flex!!! Every vehicle Ive painted since 04, I have added flex agents to prevent future problems that I'm referencing. Normally (current factory finshises) these additives are used only on plastic parts to allow for flexing that I have described in each of my posts. Heres another insert from Martinsenour paints (for those whom know nothing about auto finishes its NAPAS house brand made by sherwin williams)............................
Martin-Senour Urethane Flexible Additive 3084 offers you the advantage of one flexible additive for acrylic lacquer,
acrylic enamel, polyurethane enamel, acrylic urethane enamel, and primer-surfacers. It adds flexibility to each of
these systems. Plus, it’s easy to use and can be applied over a wide variety of semi-rigid and flexible plastic parts.
It offers the following benefits:
• Convenience of stocking just one additive for many different finishing systems
• Fast drying time lets you get the job done quickly
• Long usable pot life
Urethane Flexible Additive 3084 is the most “flexible” of flexible additives. Use it with more finishing systems than
any competitive additive. Pot life of 3084 is twice that of competitive additives. Plus, Urethane Flexible Additive
3084 can be used over a wide variety of semi-rigid and flexible plastic parts.