P2 Undermask

Chris- Will you had sculpted all of the mandibles, and then took them off. Kinda would have been better to finish them and make the full blown mask. My two cents, but your project.

The key with ultracal is to do as few batches as you can and bond one to the next before the stone fully heats up. I put on a detail coat, building it to 1/4 inch thickness or a tad less. Just as the surface turns matte, but builds no heat, I brush on a layer of the next batch and go in with my burlap, about 4-6 layers. Basically you want to build the bulk of the mold thickness with burlap soaked stone. Then I follow that with a 1/16 inch or so thick finishing coat to smooth it over and make it pretty. When you apply burlap you need to make sure you are not creating air pockets and it looks like that is what happened too you, and that your detail layer was not too thin there. Just like Polyester resin, when it is thin, the stone has limited strength, so building up the detail coat to thick can cause serious cracking during bake out, or even opening the mold. Never make a part of a mold thicker than it has to be, especially if that part contains no reinforcement.

I am actually writing a book on this stuff. I have a 36 page worth of text chapter just on molds. Devil is in the details. Stone molds, like anything else, takes practice, and you need to develop a feel for it. It does not work in our favor that ultracal today is not even close to the quality it was 10 years ago. Some people are switching to dental stone for this reason.


Veteran Hunter

As above, Do not stress, soak the areas that are damaged in water, and trowel in a fairly thick ( but wet ) layer of plaster, then just reverse sculpt the details as it sets up, wont take you more than a hour or so, you may need a few small batches, but its easily fixed where you have the issues.

good luck.


Here is what i did when that happened to me i just took some clay molded it in the cast smothed it out and pored the latex when i was done you could hardly tell that there was any damage and the latex wont stick to the clay in the cast just let it sit a little longer to dry
Alright guys thanks for the tips I'm going to go try and fix it up now. Also, could it possiblly be that I used old ultracal on the front and brand new ultracal on the back? Just wondering.

that works too, buuuuuuuuuuuuuuuuuuuuut if you patch with Ultracal it will be permanently repaired. I often add a bunch of acryl 60 to my repair batches of stone, but you should be OK if you soak some water into the area first. A note, the thinnest parts of the repair will cure first so pay attention to them. Soft work with a wet soft brush helps to smooth and to provide a bit more work time when the stone is starting to set. You will only buy a few minutes though. Let the patches core for like 2 hours or so. Remember to bake out your mold when it is done. I like to do about 12-16 hours at about 200. This will strengthen it and dry it. Do not remove it from the oven until it is cooled. That takes about 4 hours.
The different ages of your stone is not likely the issue. It is more likely that your burlap layer did not make contact with the detail layer. It happens, just learn from it. I once had a lab assistant make 10 full head and shoulder positive in ultracal, and she just screwed them all up, not pressing that burlap carefully into place. She also did not mix the stone thick enough to boot. Well, these came out of a silicone mold, so we had no idea. Well after we made the negatives, and we opened them, massive sections of each head just came off from the burlap, and we have to reform the positives, 10 of them, to fit perfectly against the negatives. That is no easy task. It took so much damn time, and a lot of precision. Ughhhhhh Memories
Okay now that i have fixed the mold, how do i go about pouring latex for the first time? Should I do it like any other time. Is there something different i should do the first time? Let me know I'm looking forward to pouring some latex for the first time today.



I didn't cast a mask, but I did cast a pair of boots. I first brushed on a coat of baby powder, which makes the mask coming out easier. For the first time, I brushed in a beauty coat of latex so that it would grab the details. I then poured the rest of the latex in so that it would level off at the top of the mold. You may have to have a small cup to pour some of the latex onto the areas of the mold if the latex doesn't come up as high. I also rocked the mold a bit to release any trapped air bubbles too. I let it dwell for 40 minutes and agitated the mold every 15 minutes. Then, I poured the latex out, rotating the mold so that the latex would come out and evenly coat the sides. Also make sure the latex doesn't build up in any areas like the mandibles, etc...it would take a while until the latex would dry. I let it sit next to a fan for ten to tweenty minutes to allow the latex to gel. Then, you can repeat the process until you gain the desired thickness. When you reach your desired thickness and let it fully cure overnight, pour some more baby powder onto the latex before you pull it out. That will help the latex not stick to itself. I'm not sure how many pours the average mask is, but I guess that would depend on the person who casts the mask.
Thanks Munson. Another question popped into my head when I went to check on the mold. Because my garage is detached from the house it doesn't have any kind of heating so it gets pretty chilly out there will this cause any problems?

it is far more common, when dwelling, to do it in one shot. The time is determined by the temperature of the room and the stone you used for your mold. 75 degree room, and a hydrocal mold is about 1 hour usually.
Now that the latex is drying within the mold, lets talk about foam filling. Should I just remove the back half of the mold, make the slit in the neck, put the armature in, and then foam? Or should I do something else?

Without a proper core, and something to secure it to, foam filling is gonna be tough. If you are using expanding foam, you will not be able to wear than mask for at least three weeks, unless you want to die or end up in the hospital, or at least risk those things. If you armature is the size of your head, then the mast will conform, but if it is a mannequin head, foam filling is going to create too small a cavity for your head. This whole process should have been addressed in the beginning. When making a mold, it is key to know what that mold is for to design it properly. You have put yourself in a tricky spot.
Foaming is probably the one thing that I did plan ahead for. When I made the mold I made sure to mold part of the armature so when I went to foam it would sit nice an snug against the mold. And it would be line up exactly to where I sculpted it. I just need to know if I should pull the mask out first to inspect it or if I should leave it in and foam it. Also how long should I wait until I foam it. I poured the latex yesterday and when I went and checked it an hour or so ago it was still a little gummy but it didn't stick to my finger, so would it be okay to foam it now or should i wait another day?



Veteran Hunter
Chris when it is fully cured, just do it alittle foam at a time, i did that with my wolf/P2 and silicone p1, you can always cut out the excess if its too big.

people often over complicate things for the sake of it, and as this is a HOBBY not HOLLYWOOD, we do not have to be all " planning ahead and doing it all AS PER THE MOVIES "

just enjoy dude.
You can cut the excess out. If you are using a stiffer foam like 4lb or 6 lb it may feel scratchy when you wear it. Again, wait at least three weeks before wearing it, for your safety. Where are respirator when cutting the foam out, at least if you do it soon after casting. Always wait until your material is fully cured before foaming. The reason I meant plan ahead, is that if you design it right, you can slip the positive in and fill. That is kind trick with latex. So, you might need to just foam it and rotate as the foam cures, then trim out excess. It will be easier than filling it solid and trimming.

Guys, I am not trying to say you have to do it the Hollywood way. At the end of the day, whether you are in Hollywood or the middle of the Indian Ocean, planning saves on mistakes that can waste material, waste time, or even cause injury.
ome clean up and the repair spots are noticeable, but other than that I'm happy about it. It was definitely a learning experience. Anyways on with the pics.
img]http://i65.photobucket.com/albums/h212/Supreme_Hunter/P2 undermask/DSC01753.jpg[/img]
img]http://i65.photobucket.com/albums/h212/Supreme_Hunter/P2 undermask/DSC01756.jpg[/img]
Thanks again guys for helping me through the process.