Application of HumiSeal® UV500

Conformal coatings can be successfully applied to substrates that have been cleaned prior to coating and also to substrates assembled with low residue, “no clean” assembly materials. Users should perform adequate testing to confirm compatibility between the conformal coating and their particular assembly materials, process conditions and cleanliness level. Please contact HumiSeal^® for additional information.

Spraying
HumiSeal^® UV500 can be applied via standard selective coating equipment or by conventional hand spray equipment. The source air used for spraying must be dry (a dry inert gas (nitrogen or argon) is highly recommended) to prevent premature curing of the secondary cure mechanism.  The spraying should be done with adequate ventilation so that the vapor and mist are carried away from the operator.

Brushing
HumiSeal^® UV500 may be applied by brush for rework or touch up only. Brush must be cleaned with solvent promptly after use.

Curing
HumiSeal^® UV500 is a highly cross-linked coating. In order to achieve maximum cross-linking density, the product must be exposed to the correct spectral output. Humiseal has modeled the performance of UV500 using Arc and Microwave based UV curing equipment. The table below outlines the required dosage and irradiance values necessary to render HumiSeal^® UV500 tack free post UV exposure with both equipment types. Minimum figures should provide a tack-free surface. The maximum recommendation represents the highest tested values by Humiseal. The cure recommendations may change as curing technology develops.

Clean Up
To flush equipment and clean uncured HumiSeal^® UV500, non-alcohol based solvents should be used. HumiSeal^® Thinner 521 or Thinner 521EU is recommended.

Rework
HumiSeal^® UV500 is a highly cross-linked UV cured coating.  The cured film has a high degree of environmental and chemical resistance and will be more difficult to remove than traditional conformal coatings.  Thermal displacement and mechanical abrasion are suitable options for rework of HumiSeal^® UV500. Humiseal Stripper 1072 and 1100 can be used effectively to remove UV500 after full moisture cure.