Film properties problems

Trouble

Possible Causes

Solution

Color – Off shade

Stoving time too long

Adjust line speed

Oven temperature too high

Decrease oven temperature

Foul oven air

Check gas supply, burners and venting.

Bare Edges / Areas – Pinholing and gassing through coating surface

Poor cleaning, metal preparation or dry-off

Check pre-treatment equipment, dry-off oven and part drainage.

Film Aspect – Texture pattern or metallic effect incorrect.

Guns too close or distant from component

 Adjust distance.

Powder delivery too high

 Adjust.

Film thickness too high or low

 Adjust.

Poor Mechanicals – Poor impact resistance, poor flexibility

 Undercured

Increase oven temperature.

Increase dwell time in oven.

Poor cleaning or pre-treatment

Check pre-treatment equipment and chemicals.

 Film thickness too high

Reduce film thickness by adjusting application equipment.

Change in substrate thickness or type

Check substrate with supplier.

Adhesion – Poor adhesion

Poor cleaning or pre-treatment

Check pre-treatment equipment and chemicals.

Change in substrate thickness or type

Check with substrate supplier.

Undercured

Increase oven time.

Increase dwell time in oven.

Chemical Resistance – Poor chemical resistance

Undercured

Increase oven temperature.

Increase dwell time in oven.

Surface Hardness – Poor pencil hardness, poor abrasion resistance

Undercured

Increase oven temperature.

Increase dwell time in oven.

Overcured

Reduce oven temperature.

Poor Flow – Too much orange peel

Film thickness too low / high

Increase / decrease film thickness by adjusting application equipment.

Oven temperature too low

Set oven to correct temperature.

 Heat up rate too slow

Modify oven baffling heat rate at front of oven.

Gloss Too Low – Too low for high gloss powder

Incompatible powder contamination

Clean application equipment before changing powders.

Micropinholing from gassing

Check component for porosity.

Check component for moisture.

Check powder for moisture from reclaim or compressed air.

Check film thickness, coating too thick.

Gloss Too High – Too high for low gloss powder

Undercured

Check burners, isolate oven.

Increase dwell time in oven.

Contamination in Powder

Reclaim in-line sieve torn

Repair sieve or replace if necessary.

Contamination from plant air circulated through spray booth

Isolate and preferably enclose spray booth area.

Film Thickness – Inconsistent film thickness

Guns positioned incorrectly

Check and reposition guns.

Reciprocators not matched to line speed

Adjust line speed.

Adjust reciprocator stroke.

Air speed in booth disturbing spray pattern

Consult your equipment supplier.

Defective spray equipment

Consult your equipment supplier.