Hydrocal pits (air bubbles?) in mask mold?


I've rewatched Tim Martin's course on latex mask making a few times now, and I've tried two masks and gotten huge cratering happening in the mold process. What's happening is when I clean out the mold and am scooping out clay, my fingers will brush against the interior of the mold and it just crumbles under any pressure, or I'll pull clay out and it'll come out with an eggshell-thick piece of hydrocal exposing the burlap layer behind it (See photo)

I'm doing the splash coat of hydrocal, and then layering on the hydrocal/burlap mixture as per the video, but I must be doing something wrong?
I'm assuming these are air pockets between the splash coat and the burlap layer? 

Is there a good way of preventing this?

Thanks for any and all help!


  • Options
    Looks like you trapped some air.  You can avoid this by making sure your burlap is fully saturated during application, and carefully pressing/tapping it into place allowing any trapped air to escape.

Sign In or Register to comment.