100 feet of what is essentially a condenser. Can you shorten the amount of line/hose between the compressor and gun? Rig up a separator/filter to hang on a belt around your waist plus a desiccant dryer/filter at the gun. These are just suggestions to reduce the risk of contaminants from the air supply.
You need length so the air can cool and condense so the trap can get it. Then I am using the desiccant at the gun so its not a contaminant issue. When I touch the areas the IR heater has been on it is much better vs the parts that haven't seen it yet. I may have to wait till June again but I am hoping not.