I need help with a problem I have been fighting for 6 months.  We currently use Uralane 5750 on hi-rel PWA's used in space applications.  Our method of applying is the brush method per NHB5300.4(3J) April 85.

The quality requirements state that "Coating shall be free from contamination or foreign material.  Any contaminant visible under 4- to 10- power magnification shall be cause for rejection."

My problem seems to be the properties of Uralane 5750.  It seems to remain tacky after it is cured and this appears to attract all airborne particles.   Our CSI and GSI inspectors naturally crank up the scopes to 10 power.   I used Humiseal 1B31 in the same environment and do not have the same problems.

My main customers Boeing and TRW have both issued CAR's against this process as it realates to contamination.  I am in need of any input that may help me improve my process.  I am a NASA certified Instructor in Conformal Coating and Staking and have not been able to solve this problem.

Any information that would aid me in continuing my career would be greatly appreciated.

Pat Lujan
Senior Mfg. Eng.
BFGoodrich Data Systems Div.
Albuquerque New Mexico   USA
505.938.5373 

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