Restoring old moulds / miniatures for casting

[Andrew Beasley]

I’ve been watching (with a large measure of nostalgia TBH) the rereleases of the Alternative Armies figures (such as this news article)  and it got me wondering ‘how the heck do you do this‘?

From the little casting (resin not metal) I have done, the mould will rip so creating flash or lumps when reused or worse split and if I try to recast something I have done previously the quality drops.

Trying to match cloth folds / armour rings / scales seems way harder than the original build and must leave join lines???

So I’m baffled – the Dragonet (see above for the link) looks just as I remember him (never did paint it so its an ace match in that respect)… Anyone know how you do this to such a fine level???

 

[Mike]

If you still have the original master or the spins from the master used to make the production mould just as normal.

[Leon Pendraken]

As Mike says, if you’ve got decent quality master moulds then you can just spin up some castings and make new production moulds.

However…

If the master moulds are knackered or too old, it can be a real pain in the backside.  We bought up the TB Line ranges a few years ago and the moulds that arrived were an eclectic mix of masters and productions, contents all over the place, figures missing, etc.  And all done in low-temp silicon which isn’t designed for high-volume production.

So we’ve had to spend ages spinning all of the moulds to try and get enough decent quality castings out of them.  We then have to go through each casting carefully and repair/clean-up as needed, to make them good enough to go into a new production mould.  It’s a laborious task and not much fun at all.

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[Mike]

Did you not have any of the actual masters/greens to use?

[Leon Pendraken]

We had a handful but they were too beaten up from the master moulding process.  The rest had gone missing somewhere along the way (we’re the 3rd owners of the ranges) so we had to resort to master castings and a ton of cleanup work.

www.pendraken.co.uk - Now home to almost 6000 products, including over 4200 products in 10mm, plus MDF bases, Vallejo paints, I-94 decals, Red Vectors MDF buildings, Raiden Miniatures, Militia Miniatures and much, much more!

[Andrew Beasley]

Thank you for that insight.

I had heard of masters but assumed they where the ‘greens’ or sold (blush).

Is the quality of these figures that much better then?

I take it if these are not available then it’s find the best quality cast you have and go from there?

[Tony S]

I thought the greens were usually wrecked by the moulding process?  I understood that the masters were the first castings spun from that mould using the best (but expensive) alloys for the best detail replication, then production moulds were made from the masters?

And then both the first mould from the greens, and the cast masters were carefully put away, so to be able to remake the production moulds as they wear out.  Theoretically that’s the procedure I heard about.

I know a few sculptors and workers from the old RAFM days, and that’s what I understood from them anyway.  Do you get a sculptor to repair the damaged greens?

[Mike]

I have had only about 200 models cast over the years, so not much by some standards.

However only may be 10 of the greens were damaged during master mould making.

[Mike]

Tony S wrote:

And then both the first mould from the greens, and the cast masters were carefully put away, so to be able to remake the production moulds as they wear out.  Theoretically that’s the procedure I heard about.

 

This is what people did for me.

[Leon Pengilley]

It varies quite a bit depending on what’s being moulded really.  Anything made with an armature and putty can go into a regular organic master mould, but these are made at a higher temperature and there’s more chance of your sculpts (greens) being destroyed.  Smaller figures tend to get damaged easier as well, just due to being thinner and not withstanding the moulding process as well as a chunky 28mm sculpt.

Sculpts made from plastic, wood, resin, etc would be done in a low-temperature silicon master mould as they can’t cope with the higher temperatures.  These take a lot longer to make but the sculpts will likely survive the process relatively OK.

You can choose to master mould everything in the low-temp stuff to save your sculpts, but the low-temp silicon is currently about 3x the cost of organic rubber so it’s a much bigger cost outlay when you’re making a lot of moulds.

Once the master mould is made, you’d spin it enough times to get the figures you need for your production mould.  The master mould is then put somewhere safe in case you need anything from it in future, and the master castings go into a drawer here in case we need to make a fresh production mould down the line.

www.pendraken.co.uk - Now home to almost 6000 products, including over 4200 products in 10mm, plus MDF bases, Vallejo paints, I-94 decals, Red Vectors MDF buildings, Raiden Miniatures, Militia Miniatures and much, much more!

[Author]

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