Some Questions About Silicone Molding...

[MandoMan531]

So my WIP helmet master thread is over in the pepakura section and I'm planning to mold it. I've done research but I still have a few questions...

1: I know I'm using smoothcast300, but which silicone?
2: do I need release agent?
3: mothermold, fiberglass or smooth on?
4: is clay ok for a parting line?

I'm making a list, so I can order everything ahead of time(release agents etc)

So anyone with experience..Adam, Spase, anyone.. The a bit of recmmendations. Thanks!

 

[tlither]

I'm glad you are asking questions before you start. BUT, you should have sent a PM to one of the folks you mentioned in your OP or someone else with the experience. I unfortunately can't help you as I have no experience with molding. PM someone with experience and ask a mod to lock this.

 

[MandoMan531]

actually I did awhile ago. But I know they were busy, so rather than flooding them with pm's, I posted this. They can lock it if they want.

 

[Ral Partha]

So my WIP helmet master thread is over in the pepakura section and I'm planning to mold it. I've done research but I still have a few questions...

1: I know I'm using smoothcast300, but which silicone?

Rebound 25 is the easiest one to use.

2: do I need release agent?

Usually no but it doesn't hurt to use one.

3: mothermold, fiberglass or smooth on?

I'm not sure what you're asking here. You need a mothermold no matter what and it can be made of fiberglass, plaster of paris, Plasti-Paste, etc.

4: is clay ok for a parting line?

I think there is a major confusion on your part here. A parting line in an imaginary line on the model that represents where the silicone mold is going to be cut. You must be thinking of registration keys. Personally, I wouldn't use it.

 

[MandoMan531]

Rebound 25 it is, i did some more looking around last night and that came up alot.

I know i need a mother mold, the question was whether or not to use fiberglass like some had, or something from Smooth on, and by Smooth-On i mean Plasti-Paste but i couldnt remeber the name from the video(molding of the ODST helmet).

Actually i was going to make a 2 part mold, similar to the Moldmaking sticky by falcon NL, so i dont think theres a major confusion. I had originally thought about doing it like in the ODST mold making video, by covering the entire thing and then cutting it halfway an peeling it off, however im not sure it would be easiest considering the level of detail in the MKVI helmet versus the Halo 2 ODST. Heres my plan so far, assuming the master is totally finished with detailing etc.

1.draw a perfect line bisecting the left and right sides of the helmet
2.use clay (modelling clay, whatever?) to build a wall on ONE side of the line, not covering the line. edge of clay wall = edge of line.
3. make this side of the mold complete with the mothermold, jacket, whatever.(make sure to include some type of keying system into the mold
4.then either leave that side of the mold in place and do the opposite side, or remove that side the mold and repeat step 2, on the OTHER side the line.

Thanks for the info Ral Partha, hope to see some more of those godly unfolding skillz. and BTW sorry about the vagueness of the mothermold question, i was at work posting from my iPhone.

 

[LastSpartan]

Plasti-paste is easier to use, but heavier. When your helmet will have a few layers of SC300 poured in it, it's gonna be heavy to slush it. Fiberglass is hard, in both ways. Hard to break, hard to use if you have no experience with it.

You can make the seam wall with clay. It's easier in fact because you can carve keys in it for your silicon and your mothermold.