I just got done with the tedious job of stripping the clear off the outside rims of my R98 webspoke wheels, sanding all the oxidation off, and repainting clear. I was loading them into the car to go get new tires installed when I bumped one into something and the new paint chipped. Playing with the area I noticed when I press the edge of a fingernail into the paint it would create a bubble. So the paint did not adhere well to the super finely sanded aluminum rims. I sanded with 3M Trizact 5000 grit to get a near polish finish.

I used U-Pol Clear #1 that my local auto paint supply recommended. Its a single part clear in a spray can.

I'm sure a better solution is a 2k clear. A different auto paint store didn't have a good recommendation for me.

In doing some research I found someone recommending POR-15 Glisten which seems to be specifically formulated for application over polished metal. Anyone try this?

Any other success stories in this application?

TIA

 

After some additional research it looks like POR-15 has replaced Glisten with their 2k Urethane Clear.

 

I suspect the issue is surface prep .....

most automotive clear is intended to be applied over 'base coat' which was itself applied over a primer base. The primer provides the physical bond to the metal, the base bonds to the primer and leaves a somewhat rough surface that the clear can physically bond to. The clear needs something to 'grab'. Application instructions in the technical data sheet for the product you used say: Abrade solid colored coatings wet or dry with 800-1000 grit sandpaper. You provided a highly polished surface and this means the clear can easily lift .... lack of 'physical bond'.

If you look at the POR product they recommend use of their 'metal prep' if going over base metal ... this solution etches the surface. If you look at rustoleum clear, instructions for directly applying to metal call for sanding the surface to 'remove gloss'

In general in a base clear system the BASE surface is 'dull' or 'rough' ... the CLEAR provides the smooth SHINE .. . (I've been to some Sherwin Automotive paint training classes)

(p.s. if you have never used POR products before READ ALL INSTRUCTIONS CAREFULLY .... clean up requires their solvent. Regular thinners and cleaners will not clear your equipment (or skin!) You can quickly ruin a spray gun if not ready with the proper cleaning materials. This stuff requires some different handling procedures. I've used POR a BUNCH on my 79. Applied over a properly prepared surface you can beat it with a hammer and it won't chip. BUT, I use an old kitchen knife as a stirrer and pallet knife. It is a 'polished surface'. Residual POR that dries on this surface can be peeled off in a sheet cuz it won't bond to the smooth untreated metal.)