Steve- I'm probably the culprit that put that report on TN long ago- and  
again recently. Liquid solder masks often use fumed silica as filler/thickener  
to keep it in place. This is often sold under the Cab-O-Sil tradename.  
Aggressive cleaning agents can dissolve off part of the under or un cured solder  
mask polymer, exposing the while silica filler. When you heat the undercured  
mask, it will soften and allow the filler to sink down into the polymer, so the  
solder mask all looks green again. 
Re the curing from wave solder, this may not work if you are working with a  
UV cured mask. That's why it is important to monitor the output of UV lamps,  
which not all shops do, thinking that UV lamps behave the same as incandescent 
 lamps- which they don't. 
Yes, the heat gun is a very inexpensive $0.05 test, quick, easy and  requires 
no instrumentation. 
 
(Steve- I have some photos of the differences between one, two and three  
passes under UV lamps to show the difference if you'd like them. If so, pls give  
me a mailing address.)  

Bill  Kenyon
Global Centre Consulting
3336 Birmingham Drive
Fort Collins, CO  80526
Tel: 970.207.9586   Cell:  970.980.6373

**************A Good Credit Score is 700 or Above. See yours in just 2 easy 
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