Casting Fimo

[Maloink]

Hi all

I noticed that the sculptors for the Confrontation line use fimo to sculpt their originals, instead or GS...

I thought polymer clays weren\'t viable for minis because they don\'t stand up to the heat and pressure of the molding process?

Anyone with info to shed light on this please do so...it\'d be greatly appreciated...

-M

 

[Maloink]

anyone?

 

[Shawn R. L.]

I have made quite a few masters for molding out of fimo. The molds we used for resin casting were out of a very rubbery two part stuff (expensive too). The mold \'stuff\' while curing is cool, not hot. Fimo, once baked-cured comes out with the strength of, say, hard wax, mabey A BIT stronger. It molds fine. The problem is getting it out of the mold. You can count on some if not all of the master will crumble in the process of removing it from the mold. It\'s wonderful stuff to work with. Especially for organic shapes. It dosnt sculpt so well once baked. The stuff used for pewter casting is, I think, a much denser rubber and very hot when creating the mold. Most plastic would melt in the process. I dont know about fimo.

Good luck.

 

[frenchkid]

I know fenryll also cast a lot of stuff made from Fimo, as well as warcrow. So I guess it\'s prety much doable. And I find it much easier to work with then green stuff.

 

[Spacemunkie]

Loads of sculptors use Fimo for minis. There don\'t seem to be too many problems making RTV moulds and pewter/white metal casting from them.

Then again I\'m not a mould maker. But I know a man who is......

 

[Maloink]

Ok...so I\'m getting the impression that those who sculpt with Fimo are having their stuff cast in RTV Rubber, and then the Pewter is cast using RTV molds instead of the traditional vulcanized rubber?

Can Pewter be cast in RTV molds?

I can see where this would work, as the RTV molding process doesn\'t subject the Fimo to undue heat and pressure.

I\'ve cast with RTV before...I used to sculpt action figures and garage kits for a living , and I mainly used sculpey, which I molded with RTV rubber...no problems with the original surviving the molding process overall.

I much prefer polymer clays over Green Stuff...which is why I ask.

thanks,

-M

 

[Sturmhalo]

I\'m sorry, it\'s late and I wasn\'t paying attention, but I thought this thread was called Camo Fisting...

Maybe I\'m on the wrong forums...

 

[minimaker]

What Maloink said is partly correct. Fimo masters stands a big chance of not surviving the average vulcanised mouldmaking process. The combination of heat and pressure can break it to pieces. So it\'s not the best material to use if it comes to survivability. Nevertheless there are many sculptors using Fimo and moulds can obviously be made from them. I know of three ways to go about it:

- Put it through the \"standard\" moulding process anyways with the same rubber, possibly at the lower temperature at a longer time. This can mean you simply sacrifice the master. I think this is what Warcrow does since the owner told me their Fimo masters don\'t survive the moulding proces.
- Use a mould material that is softer and vulcanizes at a lower temperature. TFT does this. Vulcanising takes more time and the mould material is more expensive. I.e. higher costs (about 33% more last time I asked).
- Use a RTV rubber mould for making the masters. This is a more elaborate process that will often take quite a bit of time. The material is also a fair bit more expensive. I think there are several companies doing this. Especially those who get masters of vehicles made in plastics.

I\'m not sure what the process is that Historex uses and how well the Fimo masters for Fenryll survive. Sylvain, you\'re around? Do you know? Otherwise I\'ll ask Gantalf. Anyway, the French are good at handling Fimo since they have some companies that are set up to deal with this material. So they can do it cheap enough to keep it interesting.

My advice on the use of Fimo; if you don\'t want to have your stuff professionally cast: go ahead. If you do, then keep in mind not all mouldmakers and companies will accept it which limits your market. Always check with the mouldmaker first and keep in mind you using Fimo can make the process more expensive and therefore less interesting. Also keep in mind that your master has a lower survivability, so don\'t get upset if it\'s returned in bits. As a matter of fact, this can even happen with Green stuff master which are actually a fair bit stronger since they have some flexibility.

Oh, nearly missed the last questions by Maloink. The mouldmaking process is master - moulding of master - casting of mastercopies - moulding of mastercopies to make multi-cavity production moulds (for which the \"standard\" mouldmaking process can be used). Metal can be cast into RTV rubber but only if you use the quality that can withstand heat (it\'s normally indicated on the can).

Bye, Ming-Hua

 

[Maloink]

Thanks for the clarification Ming

I\'m fairly familiar with the molding process for both RTV and Vulanizing...I\'ve just never heard of using Fimo/polymer clays with the Vulcanizing process, as I\'ve always heard it\'s not the best material to use....polymer clays don\'t do well at temperatures over 300*

I suppose resin master are out of the question as well? Does resin stand up well to the vulcanization process?

Call me curious...if I can avoid using GS, I would prefer it...just nt a fan...

-M

 

[minimaker]

Mastercopies are sometimes made in resin since some of them can withstand going through a vulcanizer. One thing that\'s important is that there are no enclosed airbubbles. As before, check with the mouldmaker first.

As to not using green stuff, it\'s as I said, you can do that but it will mean fewer companies will be able to accept your miniatures. If you want to cast resin mastercopies to avoid using green, you can too but you have to figure out the right business deal as you\'ll otherwise end up paying those costs yourself.

Bye, Ming-Hua

 

[Spacemunkie]

Making a 2-part silicon mould of your master and casting a resin copy for pewter moulding is not difficult. After speaking to my friend he reckons the Fimo ones should be alright...???

 

[Prophet]

Originally posted by Maloink
I\'m fairly familiar with the molding process for both RTV and Vulanizing...I\'ve just never heard of using Fimo/polymer clays with the Vulcanizing process, as I\'ve always heard it\'s not the best material to use....polymer clays don\'t do well at temperatures over 300*

Polymer masters can be vulcanized, but not with the standard black rubber molds. Lower temperature silicone molds have to be used. They\'re more expensive and less durable though, so not an ideal choice. The master is destroyed in the process, but from what I\'ve been told, it yields a good cavity.

I suppose resin master are out of the question as well? Does resin stand up well to the vulcanization process?

I might be remembering wrong, but I believe there are companies that do vulcanize resin masters.

Call me curious...if I can avoid using GS, I would prefer it...just nt a fan...

-M

As long as you can find a caster who can deal with it, you\'re fine using other materials.

 

[Maloink]

Well...it seems my options are a bit more open to me than I thought...

I can cast resin Masters no prob, as I have access to a pressure pot and the results are bubble free. And it\'s a process I\'m definitely familiar with...

But if a client is willing to work with a Fimo original, I don\'t really have a problem with it getting destroyed...as long as the mold takes.

I doubt I\'ll be picking up the business again...as I\'m mostly sculpting for my own pleasure...

Still, one never knows...

-M

 

[minimaker]

Hi,

as I said, there are enough options but it does limit your market. If it\'s ok with the client you can deliver mastercopies in resin. If you want to have some technical advice on that, drop me a line and I\'ll bring you in touch with caster that have experience at that. I can also help you on contracts where you can have your Fimo stuff cast yourself.

Bye, Ming-Hua

@Spacemunkie: the process is in itself easy but the problem is can be hard to cast resins bubblefree (including those hidden by the surface). These can expand or collapse during vulcanised mouldmaking destroying details.