Tuesday, July 19, 2011

CoolMiniOrNot Instant Mould

One of the things I tried out when I was back home was a relatively new product put out by CoolMiniOrNot called Instant Mould. Having never tried casting pieces before, I thought this would be the perfect way to try it out. As it says on the CMON site, the material only needs to put in hot water to soften it, and then it sets in minutes. The best bit is it can be reused by placing it in hot water again, which means you can play around with it for a while if you're not quite happy with the result and not have any concerns about wasting the material.

I did a bit of research on different ways to use it, and ended up deciding to use the quite popular method of using Lego to build an enclosure. The mould is then created using this to make sure the two halves of the mould line up exactly the same each time.

The bit I started with was a Blaster arm for my Dark Eldar. These are very useful and hence sell on bits sites for roughly $US 5-10 each, which is a little extreme for me.

I made the Lego walls, and heated one piece of the Instant Mould (the packet comes with 5). This was placed inside the enclosure and pressed hard using a tool made of more Lego.

The presser tool

I then pushed the arm half-into the Instant Mould while it was still soft so that the next half of the mould would only cover half of the arm.

I then heated another piece and used the presser to push it down on top of the arm. This was left to dry, and then I pulled out the mould and separated the two halves. This is really easy, as the Instant Mould actually doesn't stick to anything, including itself, just like they claim.

To complete the process, I reheated the bottom half and put the top half into the enclosure, then pressed down the reheated piece over the upside-down top half. This was to get a better level of detail on the bottom half, as when the arm was initially pressed in to the bottom half, the fit wasn't very good, as you can't use the presser to make sure the mould is right up against the detail.

After leaving it to dry, I wound up with this

From here, it was just a matter of rolling up some green stuff and putting in the mould, and using the presser to make sure the details were copied by pressing down hard. The result wasn't as good as I had hoped, as some of the detail was a bit rough, but on the whole the process was very easy and the end result is very close to the original

Looking at the pictures, the back side looks a lot better than the front. Seeing as I cast the front side as the bottom half, I suspect it would be better to do it the other way around next time, since the details on the back of the gun aren't nearly as important as those on the front.

I'm also not sure that green stuff is the best material to use. I'm sure someone out there will know whether grey stuff, milliput, or anything else might hold detail better.

Also, I'm sure the quality will get better with practice. I'm very happy with the result given it was my first ever casting attempt, and the Instant Mould made the whole process very straightforward and simple. Although I was slightly skeptical at first, the product lives up to all of the claims it makes, and is a fantastic product for anyone wanting to get into small-scale casting.


  1. Thanks Jack, appreciate the research and is a seemingly easy way to take another step in the hobby.

  2. I bought some of this stuff (or rather it's japanese equivalent) about 3 months ago. I used it as part of the Tervigon build that was featured here.

    A couple of tips: Greenstuff definitely isn't the best stuff to use.

    I had better results with Milliput and I've just picked up some superfine miliput to experiment with this weekend.

    I got better results when using Talc powder as a release agent, brushing it on before I put the moulding compound.

    Finally, I use a slightly different method for putting the moulding stuff in now. Instead of one big guestimated measure of GS, i fill both halves of the mould separately, then put them together. IF you have slightly too much in each it's best as the pressure will force it into all the nooks and crannies.

    If you want more, google Oyumaru New Zealand, there's a local seller. It's the exact same stuff, in funky colours.

  3. OK, this stuff has me rather excited. I've ordered some and I will give it a go...

  4. I love this stuff. It was the product that enabled me to be able to do my fimir army. It takes a little practice, but it's very much worth the effort. I was using small plastic boxes for the moulds, the lego is a great idea.

  5. The great phenomenon given about the Mould Release Agent which is nothing but the use of talc powder for moulding compound..Its definitely the best stuff to use randomly on basis of commercial experience..