Painting the Radio Grill and Defroster Vent Caps

After removing the seats, floor mat, radio grill, defroster vents from the cab I washed the floor mat with the power washer getting most of the dirt off. I cleaned out all the loose rust from the floor boards and pans and from under the seat and treated the metal with phosphoric acid - letting it dry in the warm spring sun. For the metal parts I followed the same process as I used for the Air Vents by

1. Bead blasting the part
2. Treating rust with a 24 hr dip in 25% phosphoric acid solution
3. 2 coats of high fill primer 
4. light sanding to get off the rough spots with 600 grit samdpaper 
5. Finished with 2 coats of  semi-gloss (Satin and Gloss were too bright) black rattle can paint which actually went on very smooth. 

but decided to add a couple of variations to see what happens when I

1. heat the component after painting
2. sanding after last coat of paint with 1200 grit wet sandpaper
3. buffing after the last coat of paint.  

The radio grill was a bit of a puzzler right off the bat as I quickly realized that turning the screws wasn't releasing the grill from the dash, reaching up under the dash  I feel that the screws holding the grill on the dash also held the speaker and screen under the dash and were secured with aluminium wingnuts. I spun off the wingnuts, rested the speaker on the heater cables under the dash and lifted off the grill from the dash.

For the Grill and vent caps, I bead blasted the old paint off  and dropped it into the phosphoric acid solution and the next day, sanded off the remaining discoloration and paint bits. I also threw the screws into the same solution.  I painted 2 coats of primer and sanded lightly with 600 grit sandpaper to get the nubs off.

Grill 

Removed from dash

Primed with high fill 

After spraying 2 coats of Semi-gloss black enamel I baked in the oven at 225' for 1/2 hr. The heat must have been to hot as the paint bubbled. So I sanded off the paint and most of the primer, re-prepped and re-painted; this time baking at 175' for 1/2 hr. The paint was hard and flat and I liked this outcome.

Baked Grill

I primed and painted the defroster vents ...

Primed vent caps

Variation #1: After painting the vent caps I then tried to sand them with 1200 grit sandpaper. This was an exercise in futility (it didn't work!!) as the sandpaper scratched the finish and left a white glaze on the paint. I want to learn how to use fine grain wet sand paper to get a hard shine on enamel paint. I will have to read some more about this process and try again.

Variation #2: So, I sanded the vent caps back down to metal, re-primed and painted and this time I buffed with fine compound by hand with a damp cloth. I liked this outcome.

Buffed vent caps

I then re-installed the grill and vent caps back into the dash.

TOOLS:
The screws required a phillips head screwdriver and I used my hand to hold the wingnuts.  I used the same primer and paint used for the kick panel vents - Rustoleum Semi-Gloss Black and Dupli-Color High Fill Sandable Primer for the dash metal. I used the oven in the house (there really wasn't any smell) and the compressor and bead blaster I had procured earlier to strip the old paint off the metal.