Newbie Sculpting Questions - Help!!

[Jagannath]

Hullo folks,

I've decided to take learning to sculpt a little more seriously this year (hence having a lot less painted to show off recently) and I'm easing myself in (relatively speaking, it's still bloody difficult) with something I've wanted in 15mm for ages - Plaguebearer type beasties.

I've got the basic legs and body shape of 5 on corks with another 5 started - soon I'll be on to arms, heads and details.

I'm working towards getting them cast - they may not be good enough in the end, but if I have that as an aim that's a good way of keeping my standards up.

I've got a question about casting though - what are the limitations on weapons, shields etc - an I make things out of plasticard or is that an issue for casting? I appreciate I'll need to anchor them well to the model so they don't snap off, but is there inherently any issue with using other materials? Or does the mold making process cause an issue (is it exothermic)?

Any help much appreciated (I'm looking at you Nic-e!)

[Connectamabob]

A silicone mold for casting resin: no problem. That stuff does everything at room temperature. It probably is very very slightly technically exothermic, but not enough to be meaningful or even noticable (if you touch it while curing, it won't even feel warm). Before 3D printing became common, building with styrene and molding with silicone was how all non-figure/creature garage kits got done. I've seen people pull molds from chocolate bars and raw fish (not at the same time, of course).

Vulcanized molds for metal spin casting might be a problem though. It's not something I'm personally experienced with, but IIRC the temps involved in making the mold exceed the glass and/or melt temp of styrene.

I've seen sculptors use styrene sheet or rod to add details to GS masters before, but I assume they were sculpting for a production pipeline that involved casting resin intermediaries instead of just putting the green itself into the vulcanizing machine.

[Jagannath]

Ah gotcha - is that the main reason masters are cast before the production mold I wonder? Hmmm...

[Connectamabob]

I think it's more a side benefit. Main reason, as I understand it, is to create enough masters of the same figure to fill out a mold for mass production. So you'd cast 10 resin masters from a single green, then use those to create a vulcanized mold that can cast 10 of the same figure in one spin.

I think in the old days, this was done using the same vulcanizing machinery as the production casting to create metal intermediaries, but as resin casting has become better and more accessible, resin intermediaries have become more common, as they produce less generational degradation than metal.

[Rich H]

Not sure TBH but you can cast pewter in silicone, so I'd suggest that the secondary masters are probably pewter, resin isnt suitable for high temp!

[Connectamabob]

Not true: there are many kinds of resin, some of which are suited to high temp. You just have to actually check the material data from the resin suppliers and choose the one with the right specs for your application, instead of just going with the rock-bottom cheapest garbage resin you can possibly find, like a lot of resin mini producers do, unfortunately.

Hasslefree is one company I know of which uses resin for all its intermediaries, as they sell the extras for people who want to pay a little more for crisper castings.

[nic-e]

I know from experience that plasticard simply doesn't do well in a vulcanised mould. the first model i sent off to be cast was ,rather stupidy, built around a plastic  armature. It came out the mould as a green melted blob.

Milliput can survive if you need something to do sword or weapons ,and it can be sanded and shaped to get nice neat surface.

Greenstuff is fine in a vulcanised mould but it will come out brittle and your sculpt may be destroyed in the process even if the mould works, so be prepared for that.



With regards to making a resin master, remember that resin in a silicone mould needs to flow. a fast setting resin could become too clingy to quick and your details wouldn't fill properly.


Remember to watch your undercuts!:)

Looking forward to seeing what you make.

(If you aren't sure about materials or what can be used for what, 4d model shop have some great articles and links, and Tirantis sculpture supply shop are always happy to answer questions about what you need to do certain things.)


(also I've been looking at getting some of my stuff cast and have had estimated from minifigs. they say that for 15mm they do £50 a mould and £40 per KG of metal spun.need to compare that to other services such as 4d ect, but that's a good baseline to look at.)

[Jagannath]

Thanks folks - 'intermediaries', that's the word I was looking for.

OK cool - I'm quite fixed on sculpting 15 odd legs and bodies (mostly detailed) now, then getting them cast, then adding details and conversions, then getting the final thing cast.

Good thing there is that it gives me more bodies to practice on too.

Sounds like I don't have a huge amount to worry about for stage one (other than the cost of casting them) but I'll need to research a bit more before I come to build weapons etc. Nic-e - that's a good thought on Milliput, thanks (I realise I have actually used it before for carving weapon blades after cured,  so that's good).

I'll pop some pictures up this weekend of the bodies.

[Ockman]

What are you working on? Sci-fi or fantasy? Or both?

[Jagannath]

What are you working on? Sci-fi or fantasy? Or both?

I've got some sci-fi space peasants on the back burner (I'm happy with where they are, going to give detailing them a swerve until I'm a little bit more confident) so I'm working on a batch of 15mm Plaguebearer/Goblin types. They're intended to look like a mix of the GW Hobbit Goblins and the old metal Plaguebearers, but in 15mm (he says ambitiously...)

[Ockman]

Looks cool!

I've sculpted ONE mini in my life (wait - perhaps two), and I am pretty happy about it. It was a 28mm hazmat trooper (and a zombie version of him). No masterclass, but still!

[Jagannath]

Had a very helpful exchange with Griffin Moulds, bit clearer now. Phase 1 is easy - 15 or so pretty much finished legs and bodies, one mould, spin up a load then convert them from there to produce variants and troop types. Fun!

[nic-e]

It's also worth remembering that your casts will shrink , and be smaller than your initial sculpt. By how much depends on a variety of factors, from alloy to temperature.

[Jagannath]

Thanks. Whilst I get what you're saying, what in particular should I watch for? Just to sculpt a touch larger or do I need to be conscious of ankles getting thinner etc?

[nic-e]

Thanks. Whilst I get what you're saying, what in particular should I watch for? Just to sculpt a touch larger or do I need to be conscious of ankles getting thinner etc?

A bit of both. just be mindful. I'f you want something to be he same size as an existing cast range, look at adding a little height. If you have very very thin swords and weapons, thicken them to stop them a bit.