Lance,

This a fairly common issue. The viscosity of the coating as well as the
temperature and humidity
are critical. The simple answer is to make multiple light spray passes
at different angles,
 letting the coating dry past tackiness between passes. Be sure you do
not exceed a 3 mil thickness (cracking in extremely cold conditions
becomes an issue).

Contact the folks at Humiseal. They will be more than happy to assist
you with details.

The "pull back" is due to evaporation of the solvents/thinners.

David A. Douthit
Manager
LoCan LLC

Lance Mayes wrote:

>Hello again Techies;
>
>We are having issues with our conformal coating on some of our components.
> It pulls back from some of the components leads along the edges.
>We are wondering if this will make a difference in the protection of the
>board.
>We're using Humiseal Acrylic 1B31 and Humiseal Thinner 521 in a mixture.
>The conformal machine sprays a nice coating and then the coating starts to
>recede.  Sometimes this happens even when we paint the acrylic manually.
>Has anyone else ran into this problem, and what to do to overcome it?
>
>This is a good one for the end of the day.  I'll be waiting.
>
>Thanks again
>
>
>                        P.  Lance Mayes
>
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