rubherkitty wrote:Glad things are progressing!
A hugs thanks to you, my friend. One question, is it still possible to do multiple casting in fiberglass without the need for a tooling gelcoat?
rubherkitty wrote:Glad things are progressing!
rubherkitty wrote:If you're casting silicone or foam using release in a non tool coated fiberglass mold I think it would be fine for many castings. Maybe you could do 40+ without issue?
The tool coat is probably more intended for casting solid resin or fiberglass in a fiberglass mold.
Probably the issue w/a fiberglass mold is the chance of scratching the fiberglass surface and transferring the flaw to the finished product.
You have to lay down a resin coat on your model to start with and I know tooling resin cost quite a bit more than Std resin. I've has this debate. Extra resin cost vs the overall time and material involved in making the mold.
How many dolls do you want to ultimately cast? You might go on the cheap first and see how it works out.
I plan to spray release + dust the mold with fine powder to give the doll more skin like texture and reduce shine. Any little bump, dip, scratch can make the doll unique and human. Mirror slick castings are more important for body panels on cars, etc.
The mannequin head is partly covered in Chavant clay. According to Smooth-On, they said to spray Shellac and then use the Universal Mold Release. It's also the same towards water-based clay. So the good news is I can just use straight fiberglass, Shellac, and mold release. Not only that, it might save me some money not having to buy tooling gelcoat!rubherkitty wrote:I wouldn't mess w/a tooling coat if you're just casting foam. Just let the resin cure real well first and maybe spray on a sealer.
rubherkitty wrote:I've been thinking about making a foam doll now. I ck'd into the Flex-FoamIt! 6 and it appears to be a open cell foam with no skinning properties. Do you plan to cover the foam doll in a fabric skin or clothing?
Foam cast into a silicone mold requires no release from what I have studied, but if you cast it in a fiberglass mold it will need release. That means the release might soak into the foam unless it's a self skinning foam. Any foam cast against a release will need cleaned up if you want to paint it.
rubherkitty wrote:I've been thinking about making a foam doll now. I ck'd into the Flex-FoamIt! 6 and it appears to be a open cell foam with no skinning properties. Do you plan to cover the foam doll in a fabric skin or clothing?
Foam cast into a silicone mold requires no release from what I have studied, but if you cast it in a fiberglass mold it will need release. That means the release might soak into the foam unless it's a self skinning foam. Any foam cast against a release will need cleaned up if you want to paint it.
You may need a specific release for urethane foam too! Here is one company I ran across as an example. https://miller-stephenson.com/polyureth ... se-agents/
They offer a release for open cell pillow type foam.
Oh I saw that video before. In fact, I have samples of foam from BJB Enterprises (BITY must the distributor for BJB) and I have spoken with them a few months back. They explained to me that I can use their polyurethane skin (BR-25 REV 1) as the skin layer and then use TC-267 100/100 as the meat. I initially was going to use them but when I saw their prices, I decided to just use Smooth-On instead because of the affordability. I would be interesting if I use some of BJB's products and Smooth-On's products, but I doubt that because both companies have a different formula for their materials.rubherkitty wrote:I just edited my above post regarding urethane release.
I also just spent some time studying the urethane skin w/ foam core idea. You might be able to paint in a skin layer on both sides of a 2-pc mold, let that firm up then bolt the mold together and pour more in the seal the joint line. This would make working around a skeleton handy.
You could try to tip the mold to cover the joint line or strap the mold in a roto cast device.
And if you are going to use a roto cast device you might just do that from the start vs painting in the skin on the 2 halves. I figure either way you go, the lower legs & feet and forearms & hands will probably end up solid urethane skin rubber. Especially if you have a skeleton. Especially on a small doll too. Can't see much open space for foam to flow into unless the skin is very thin and then you might end up w/a thin soft spot.
Candy18 dolls used to make dolls like this and they had lots of problems w/ thin spots of the skin and poor foam fill/ sometimes had air pockets in foam. But they were not high quality dolls either.
Have you seen this vid by Brick in the Yard?
https://www.youtube.com/watch?v=dQZZGyIHcbc
I have thought about using a self skinning foam, but you have to be careful about the weight.
I think Smooth-Ons lightest SS foam is 14 lbs per cubic ft free form. Compressed molding and it will be heavier. I want to do a doll around 5' but don't want it going over 50 lbs.
OK, I just researched at it says a 155 lb human is around 2.4 cu ft. Seems small to me. Figure 2.5 x 14 lbs = 35lbs + skeleton. So maybe 45 lbs.
BITY sells a Prop 10 SS foam, but it has a shore hardness of 40A. I think much of the SS foam is going to be too hard for a doll. I know they make skinned foam dolls that are soft. I just have to find the right stuff. https://www.brickintheyard.com/collecti ... am10-quart