How to harden the putty

[quang]

Hello Ming Hua,

I'm a caster myself and from my experience, RTV rubbers are hopefully more forgiving than the manufacturer's instructions or caveats.

I often use various materials on my masters and have successfully moulded plasticard and super glue-coated parts. Needless to say that my masters are a mess after the moulding process. But at least I've got my imprint.

Casting is like cooking. You may have all the cook books and recipes you want but when you're in front of the gas burner, you're on your own .

It's only at that moment that the learning process begins (and the experimenting as well).

Q.

 

[minimaker]

Hi,

RTV rubbers are indeed more forgiving. It's does not have to be squeezed and heated to create a mould, so all materials listed can be processed with that. I'm a little surprised your masters are a mess after mouldmaking. With a good mould release (I use diluted vaseline) RTV silicone lets go of the master quite easily. Well, if you don't have too many undercuts anyway. Or do you mean in natural rubber moulds?
RTV rubber is also more expensive and labor intensive than using the natural rubber discs for 28mm figure production. You need some more specialised equipment to process the material, but it's worth the effort if it comes to production.

I know of several casters who can actually handle plastics and polymer clay masters for creating masters and where these survive the process. Some companies use a new type of rubber mould disc that vulcanizes at a lower temperature, others play around with pressure/heat order and times while others still use RTV rubbers to create the production masters.
In France you've got Historex and some others who a lot of experience at that since many French miniature sculptors use a combination of FIMO for bodies, GS for details, Milliput for mechanical stuff and plastics for weapons. Those guys are very good and interesting is that they can actually offer a very good price per cast (in resin).

One thing I do tell miniature sculptors (28mm and below) is that using vulcanizer resistant material means they can work for any company while using other materials will decrease their "market" to those with casters that can handle it.

Bye, Ming-Hua

 

[quang]

Hello Ming Hua,

I guess the misunderstanding comes from the fact that we're talking about 2 different kinds of moulding rubber. The one I'm using (Room Temperature Vulcanising) doen't need to be heated nor compressed and therefore is more forgiving towards the materials used for the master.

I'm a little surprised your masters are a mess after mouldmaking.

I guess I should be more careful and spend more time when I make my masters. On the other hand, I'm happy as long as I get a good imprint. But that's just me! :lol:

In any case, thank you for your detailed input.

Q.