Where the
world gathers for metal finishing
Q&As since 1989


-----

High gloss clear TGIC coat turns out flat and dull

What could cause a high gloss clear coat to come out dull and flat? I've applied the clear coat over a candy blue w/ glitter. It's not really orange peel, but comes out with a flat, matte finish. Could it be a grounding or application problem? I am applying powder when the metal is preheated and around 170 degrees or less, otherwise the powder seems to bake onto the metal right then. Curing is at about 385 degrees for 15-20 minutes.

Brian Myers
framebuilding - San Diego, California, USA
2006

---

2006

What's the man. recommended cure schedule? Sounds like the clear is taking way to much heat. To test it, paint and cure an un-preheated sample panel 350* for about 15 minutes and test for cure and visual's.
Another thing you might look at is the way the paint is added into the hopper, sometimes mixing different batches of the same paint will cause this to happen.
Mixing reclaim with virgin paint can cause it too.
If the problem just started all of a sudden, you need to get the supplier involved.
Not cleaning the hopper good enough at color changes can cause it(cross contamination)
Some powders produce fumes when they are curing, the clear coat being in the oven at the same time as a fume producing paint could be the problem.
The air turn-over rate and circulation in the cure oven could be the problem.
It's hard to guess without knowing when the problem started or knowing more about your processes and procedures. I'd go with over-cure issue. Good luck with it.

Sheldon Taylor
supply chain electronics
Wake Forest, North Carolina