Thread: High shrinkage modelling materials

Thanks for the replys guys.
I just thought there might be a material...how else do manufacturers model such finely detailed figures in 72nd scale for example, wouldnt they be modeled in a larger size first then reduced some way?
Anyway...if i find something i'll let you know. Thanks again.

Hi m8

I guess now days they use rapid prototyping to make those tiny figures, but in the good old days the master copies were all made by hand one at a time.

:)

The only shrinkage material that still retained accurate details and coordinates that I have come across was a polyester resin with a filler added, and just before pouring, water was emulsified into the mix. This gave a shrinkage of up to about 15% spread over a few days, nowhere near to what you would be contemplating.

Modern machining techniques allow detail to be drawn almost as lifesize, complete with all the very fine details required, then it is digitally reduced to whatever size is required for feeding into the mould or die making machines. These are so sophisticated nowadays that they can reproduce detail that is difficult for the naked eye to see. It also allows for a die to be reworked later, to put in more detail or modifications as sees fit. Unlike the old days when the dies were made by hand.

But old worn out moulds very rarely die if they are a good model. There are still artisans about that can hand restore the old worn or damaged dies, but they must be getting very few and far between now.

What normally happens is that when a company goes bump, the old dies are bought by other companies, maybe restored a little, then re released models under their new owners name appear. That is why you can still buy the same kits that were being made in the 60's and 70's today. The modern versions might not have the same crisp quality, and maybe a little more flash than the old ones, but they are still coming from those old moulds. A good example is the largish Airfix Flower Class Corvette. Revell got hold of the old moulds, made a new set of build plans and transfers, and released it as their own.

I hope this has shed a little light onto the subject for you.

Bogs