I've been in the same boat. I think what I will try is making a duct tape bust of my head and using that as a core while using a soft expandable foam poured into the gap between the mask and the core. That way I'm sure it won't be too loose/floppy.
What I'm trying to figure out how to do now is make sure the eye positions on the core stay in place while I flip it upside down to pour in the foam... I can't let any foam get in between the core eyes and the eye holes in the mask.
hot glue is not the best approach. it is essentially plastic that you are melting ..then waiting for it to cool ..it doesnt allow for much flex ..and eventually more heat will soften it ( like the heat generated while wearing it) ..what you DO want to use is something that is meant for open cell foam, and that is spray adhesive. Specifically Super 77 spray adhesive ( found at home depots everywhere) spray some on your cut pieces of upholstery foam ..let it get tacky for a minute or two ..then apply right to the inside of your mask.
Now ..tehfailsafe. you are on to something, but are forgetting something extremely important ..the foam expands ..and if you insert a core ( which BTW you will need to coat in polyfoam release), the foam will be "pushing" off that and expanding outward..if that mask isnt sitting securely in a mold , that foam will keep going and distort it terribly. You can however do this if you are feeling up to playing with two part polyfoams. use very small batch mixes. pour a very little bit into the neck of the mask . Cradling the sides of the mask with both hands ..slush the foam around. As it expands it will create a nice wall of thick foam around the inside of the mask. Be careful as to not touch the foam with anything as it rises ..it will collapse on itself ..becoming a sticky to eventual hard mess.
Hm, interesting. I assumed the expansion would come up and out of the neck where it's getting poured since that would be no resistance. But I see what you're saying about the latex mask itself doesn't offer much resistance either...
Are you saying slush it around in layers? So pour a bit, slush till it expands, pour more until etc until eventually it's all the way up to the neck? Could I use a similar foam that I could re-use for making dreads? What do you recommend?
you may not need to foam it up as much as you think ..start with the crown ..areas that are obviously larger then the human head ..yes , small batch pours, slushed around until it expands ..you just need to cover the area while the A and B mix is still in its most pourable form. Make sure you stir the compound well and briskly ( very important) you can layer it up.
Im not sure what you are using for your dreads...most of the time the shore rate of the foam for dreads is pretty light ..you may want to kick it up a notch ..maybe a 6LB polyfoam for doing a head
be careful on your mixture, if it is not precise you can end up with goo that never cures, or uncomfortable "not very soft" foam. Cover the eyes from the inside if they are cut out, or it will get all over the outside of the mask too. I use a built up in size manequin head with a pole out the neck and try to keep the nose and eyes of the manequin lined up with that of the mask. When you add dreads and dread beads, the weight of the mask triples, so be sure to have snug fit.
If you are using polyfoam, remember to work in a well ventilated area, wear a respirator, and do not wear your mask for at least a few weeks after foaming. Safety first. That stuff is deadly if not treated with respect and precaution.