REINFORCING YOUR BLANK MASKS WITH LIGHT WEIGHT PUTTY (JAWS TOO)

If a section of your mask is a bit thin or you just want to make it a little more durable, I recommend trying Freeform Air!  I apply it after I do most of the rough flash trimming but before sanding the trimmed edges.

You can also use a putty like Apoxie Sculpt or even Plumber's Putty ( if you need it cured in 5 minutes, good to carry at events in case of emergency) but the advantage of Free Form Air is that it is very light but still quite strong with a little flex. It adheres nicely to surfaces once pressed in and brushed in a bit with a damp brush. You also can roughen the surface with sandpaper first to really make sure it sticks well. You can even tint it while mixing with resin dyes!

Be sure to have the mask heat shaped to fit you ( if needed) before you apply this putty. It can still flex along with the heated urethane but it's probably better to heat shape first.

It is mixed as two equal parts ( part A and part B) and depending on how much you have mixed, there is about a 20 minute window until it starts to cure and harden. A larger volume mixed will shorten the cure time since the chemical reaction produces heat and the more heat, the faster the cure. Please wear gloves because it's not a great thing to have on your hands and also it will leave a lingering scent on your skin. It also sucks to wash off, it always leaves a little film on your hands! Yuck. But otherwise it does not create a huge chemical vapor BUT still do any mixing/application in a well ventilated area and away from pets ( esp birds!)

Free Form Air will also stick to cured Free Form Air! So if you need to add more, you can. Once i mush it in with a gloved hand, i use a chip brush dipped in water to pat it down and smooth it into the surface. Don't over wet, you don't want to dilute the putty too much. It feels a lot like sticky frosting, wetting your fingers will help it not stick to you when applying. 

Give it several hours to cure before you mess with it. I let it cure overnight before i do any sanding or rasping. It will cure with a slight flex but don't push it too much! You will be able to sand and drill into it but it is not indestructible of course. 

Here is a video of me filling in a Sentinel mask with thin edges! Once this is cured, I will trim it further and sand everything smooth to get it ready to paint and finish!

UPDATE! Here is some progress of me prepping and reinforcing an owl mask who's jaw gets cut away and hinged:

BEFORE CUTTING! The light putty is Free form Air, the darker putty is 5 minute plumber's epoxy. I leave an open part where the jaw seam is going to be. This helps the whole mask have a reinforced shape before you cut anything away.

Trimmed , sanded and jaw has been cut. I then stick the jaw back together with 2 beads of super glue. Not too much glue, just enough to hold everything steady while I glue in the hinge:

Once the hinge is glued in, i use super glue remover ( pretty much acetone) to free the jaw again. Be careful, acetone can melt certain plastics! The clamps were there to hold the hinges on while the glue cooled. I use high heat/high strength Steinel hot glue for now. Once the mask is finished the hinges will get reinforced onto the mask with plumbers epoxy. 

open and ready!

You can see how uneven the edge of the mouth is since the mask thickness is not perfectly even. I use apoxie clay to backfill this!

Apoxie clay applied! I use water and a brush or gloved finger to smooth it down. Once it is cured overnight, i can sand it smooth and add more apoxie if needed until the mouth ridge is even and closes nicely!