Been asked a few times now about how I create my moulds, so here goes.
I use two different products blu-stuff putty which is a two part mixture and Modelling Reusable Sticks which you heat up
blu-stuff putty (https://blu-stuff.com/)
It's a two part mixture, it has a shelf-life of 12 month, but I found my mine went off after 6 months
• Gives really, really crisp detail
• Takes some getting used to when is the best time to apply it to the item, too soon and it squidges around, too late and it becomes too hard to shape.
• The mould can become brittle overtime and I’ve cracked a few trying to get the piece out of the mould.
• Need to make a bigger mould overlap, so the mould is less likely to break as the mould is not that flexible
• Not re-usable
• I think it’s expensive, about £15 delivered to the UK.
Modelling Reusable Sticks
There are 2 brands I’ve used Oyumaru (get it from eBay or Amazon) and Blue-Stuff which comes from http://www.greenstuffworld.com I find that the Blue-Stuff gives better detail than Oyumaru, but it’s more expensive once you factor in delivery from Spain.
• Reusable, just re-heat.
• Not been able to break a mould
• You can use a lot less as you don’t need a big overlap to stop it breaking
• Detail is ok
How to make the Moulds
How do I make my moulds and this does not matter which product you are using.
- Get a sheet of clear plastic card, it needs to be thick enough that it won’t bend too much if you apply pressure, a few mill thick will be fine.
- Now cut some square pieces about 4cmx4cm, this is going to be the base for the mould,
- Wrap the card in clear tape, you are going to super-glue your pieces to this card, so the clear tape allows you to do this and then remove and re-use the card.
- Now find the piece you want to take a mould from. The best moulds come from items that have a flat back (eg. vehicle icons) or have a flat surface behind them (Forgeworld Landraider Doors):
- If the item has a flat back, super-glue it to the plastic card and let that dry:
- Get your mould product
Oyumaru & Blue-Stuff
- Get that stuff as hot as possible in a cup of boiling water, roll it into a tight ball, then back into the hot water again, take it out and make sure there are no ridges or finger prints in the surface, put the Oyumaru in the palm of your hand and roll it with the index finger of you opposite hand, this should make it smooth.
- Back in the boiling water again (if you had to touch to smooth it out).
- Now get the Oyumaru and try not to squeeze it, it’s gonna be hot so be careful
- Make sure there is no water on the surface of Oyumaru that will be pressed onto you piece, as this will create a bubble where the water is.
- Hold the ball of Oyumaru on the end of your fingers like this:
- And apply it to centre of the piece you cast moulding from
- Apply even pressure and push and squeeze your fingertips around the piece (you’ll get the idea when you start doing it)
- Keep the pressure on and flip the plastic card over, now you can see if you are getting a good seal around the item and can squeeze in the right places – this is why I use the clear card, it helps so much!
In the picture above you can see I don't have a great seal - but I'm using blu-tac here for test pictures. If this was blu-stuff, then this mould would crack as I don't have enough overlap around the piece.
- Once you are happy with the seal, let it set, you can speed this up by popping it in the freezer or running under the cold tap, it does not take too long to set anyway, a few mins.
- Now remove the mould, it should just pop off, give the plastic card a quick flex to help it pop.
- Now you can remove the original piece you took the mould from, from the plastic card, having the clear tape on the card means you can peel the tape off and plastic card is still clear, no super-glue left on it, so easy to re-use!
- The process is pretty much the same, but you mix the 2 compounds, and apply the same way, I do find it more squish so making the good tight seal takes more practice (you squeeze the bit where the seal is not great and it pops out another area, obviously it’s the trapped air moving around), but it’s worth it.
Non-flat backed pieces
You have a few options:
Make a mould that overlaps the piece, I did this to get a mould from Ragnar’s Bling:
This leaves you with extra bits in the mould, but you can then either just only use the part of the mould that is relevant but this usually requires more clean-up on the green-stuff or get the first cast you made from the mould, take the time cleaning it up, then make a new mould from that and it should be flat backed, this means less clean-up if you are making 10+ copies, so worth it.
This was taken from the SW Venerable dred shield, you can see the extra bits of the chain I didn't need, but in this case there is come clear space around what I do wanted, the Wolf Skull, so no need to make a 2nd mould:
The other option is if you have 2 of these pieces, would you mind cutting one up to get just the piece you want and it being flat backed, could be worth it in the long run and I’ve done it many times, sacrifice a piece to get a really go mould and then I can make 100s of them when I want to.
Making the Cast from the Mould
Next process, how to make your copy, well green-stuff for me, unless I’ve made a mould of a base or similar, in white case I’ll use White Milliput or Das. But green-stuff gives the best detail.
- Mix up the green-stuff and get it hot, my rubbing it in your hands, for me the hotter the better, now that makes it really flexible, but it can make it very sticky too, so roll it into a ball, get it as smooth as possible, I mean ultra smooth as any ridges/fingerprints could end up in the cast you make.
- Drop the ball into the mould and get a tiny bit of water on the tip of your finger so it does not stick and push the green-stuff into the mould, don’t get any water in the mould as this will create a bubble in the imprint.
- Now apply as much pressure as you can to the green-stuff so it fills all the indentations in the mould, if you don’t have enough green-stuff in the mould, add some more, better to have a little too much in there, you will scrape the excess of next. I use a Hougle Board to apply the pressure to the green stuff, it’s a flexible sculpting tool and it just works better than anything else I’ve used, just apply a bit of water to it first to stop it sticking. I also use this to scrape off any excess that is above the mould.
- Now just wait, I leave my green stuff overnight to set.
Oyumaru or Blue-Stuff
- Just push the mould from behind and the green-stuff will just pop out.
- Now this can be tricky, if you have enough edge on the mould, you can slightly bend the mould and the green-stuff will lift, then use a pin to stab at an angle into the back of the green-stuff and use this to leaver it out, don’t push it in too far as you might go into the mould. You need to be real careful with getting your green-stuff out as too much bending of the blu-stuff and it will break and that’s game over for the mould.
- Try the Oyumaru first, it's cheaper and more forgiving and great for practice, blu-stuff needs a bit more experience and practice.
- So you went to all that trouble to get a flat backed cast, but now it’s going onto a curved surface like a shoulder pad? Use the cast the next day as it will still have some flex in it or make the green-stuff up with more yellow, this will make a more flexible cast.
- Clean-up is the killer, it’s like mould lines, if you take the time to make the perfect mould (even if it takes a mould from a cast, from a mould and so on), it’s still worth it in the long run.
- Take moulds from everything, I have about 200 or more, do I use them all? no, but I do use a lot of them. Also it will show you how often GW re-use the same bit
- Don’t sell your cast items, that’s illegal.
Hopefully this will be of use, it might be a bit long winded, but it's based on a few years of trying different things out and I now get pretty good results every time.
Edited by sbarnby71, 15 January 2021 - 01:25 PM.