Monster Sculpt!

Posted in Design, General, Halloween, Horror, Masks, Pictures, science fiction, Uncategorized with tags , , , , on April 26, 2017 by Jim St Ruth

My latest monster mask sculpt!

As usual, this was sculpted in Monster Clay on a Plaster of Paris life cast of my head.

The ring of clar around the edges of the sculpt is flashing and a wall, behind which I’ll build another wall made of water-based clay, before making the mould with plaster.

The cuts with the short slashes across them will be stitched with string once the mask is cast and painted; they’ll be wound stitches.

I’ve got a little more refining to do, mostly clean up… but I’m happy with this for now.

Note On Final Detail:

To create a subtly bumpy surface, I took a makeup sponge and applied a little white spirit (mineral spirits in the US, I think). Then, dabbing all over the sculpt where I wanted this detail, the clay begins to soften, and I just kept going until the texture was right… and stopped before the clay got outright mushy.

If you try this for the first time, be aware that a makeup sponge can hold a lot of white spirit. It’ll easily run down the model, which might not be a problem… but slight glances with the back of your hand can smear previously-created detail. Caution is the watchword.

Painted!

Posted in Design, General, Halloween, Horror, Masks, sculpting, Uncategorized with tags , , , , , , on February 25, 2017 by Jim St Ruth

So the finished mask came out well, though it was a little rough in places. My basic process is down now, and I know I just need to be a little more cautious when I’m filling the mould with foam. The mask was baked for 4.5 hrs in the end, and I left it to cool well before removing it.

Some pics of the airbrushing and a little stippling, though please note that this isn’t actually affixed to my face, and that there isn’t any makeup on my skin; so it hasn’t been blended in, and the opening around my eyes and mouth are clearly lose.

Oven Temperatures for Foam Latex

Posted in Uncategorized on February 23, 2017 by Jim St Ruth

So, my mask didn’t cure on the outside of the mould. I left it in the oven for five hours in total, and only the very limits of the mask inside the plaster and the foam that splooged out of the mould had cured.

Today I’m doing my next run, but I wondered if the foam latex inside the mould was even getting up to temperature. The oven that I’m using is our kitchen; an old Tricity Bendix that’s about thirty years old. It’s not a fan oven… and this over is never used to cook food in. We only use the hob above. Never use an oven that you’re going to cook in, as the released chemicals mean the oven is no longer food safe!

I decided to run a test.

A glass ramikin dish containing about 2cm-worth of olive oil. This is then covered over with a single layer of aluminium foil; not so much that the heat can’t get in.

I set my oven to 130C and left the oil in for twenty minutes to let it warm up.

The resulting temperature of the oil in my oven was 79C, just 6C off the 85C limit that I’ve read foam latex shouldn’t be baked over.

Now, I think the important two things are that it’s an old oven, so the thermostat might be unreliable, especially at low temperatures. Also, it’s not a fan oven, so the heat isn’t being circulated beyond simple heat convection. The parts of the foam latex that cured on my last run were both on or near the exposed areas, and they were also near the top of the oven.  The total height of my life cast and mould is ~ 35cm; that’s pretty big.

If you think about cooking several things in an oven on different shelves in a non-fan oven, you know that there’s a big difference between the cooking times for the different shelves.

So… I’m going to try baking at an oven temp of 110C today.

Tip: Do an oil test in your oven, like the one I’ve done. See what temperature the oil gets to at 71C on the thermostat. It might not be anywhere near the required temperatures for baking foam latex. 75C on my oven gave an oil temperature of 62C. That’s very low and, whilst I’ve read about people baking foam latex at this level of temperature, the baking times can exceed even 6 hours.

Cracked Mould… and Repair

Posted in Design, Fantasy, General, Halloween, Horror, Masks, sculpting, Uncategorized with tags , , , on February 18, 2017 by Jim St Ruth

Things went far better than my nightmares predicted!

Yet when I tried to pry the mould from the sculpt and its underlying life cast, the damned thing split into four pieces; three large pieces and one sliver along one of the main splits, right between the three pry points that I’d put into my flashing.

The solution was easy, and it’s worked really well:

  • I repositioned all of the four pieces together, which thankfully slotted together with mostly only hairline cracks visible on the inside of the mould. There were some larger chunks missing, creating some small, ragged-edged holes… Also, I realised that one of the nostril cavities had broken off.
  • Using Modroc bandages, I patched across the seam lines, then ran a ring of bandage around the whole of circumference of the mould’s outside, to add further strength. I then let this dry for a good half hour.
  • Mixing small batches of dense plaster, I then filled in the holes and the hairline cracks, only doing an inch or two’s work at a time. Moistening the surrounding plaster first, I applied the new mix, dipping my index finger in some clean water, and using this finger to remove excess plaster. Keeping that finger clean is important:
    • I didn’t want to spread the excess plaster.
    • The mould’s existing plaster soaks up water like a sponge, and this dense plaster is only in small patches, so it dries out  very quickly. A wet finger keeps it damp just long enough to smooth it out and remove any excess.
  • To restore lost wrinkles I used a pen-shaped sculpting tool with a firm, rubberised tip. Repeatedly dipping this in water as I worked on each small section, I was able to ‘sketch in’ in the wrinkles. It’s worth noting that usually I’d have to be aware that I’d be trying to created the inverse of wrinkles; as this is the mould, I’d need to texture in raised lines that would turn into the groves on the final mask. However, the ‘sketching’ I did was only shallow, and it matched the surrounding texture. I was very lucky here; the fine detail I was recreating was already faint lines and groves around where I was patching.
  • I then mixed a small batch of plaster and applied it in a relatively thin layer, around 3-4mm thick, on the whole of the outside of the mould. This covered the Modroc gauze completely, preventing me from snagging it in the future, and giving a little more strength to the patched seams.
  • Once this was dried, I found the broken nostril piece, and used a *tiny amount of superglue to stick it back on. Be careful if you need to do this; you don’t want glue seeping out of the join and into the mould itself. This can retard curing with liquid latex, at least, and leave thin spots in your creations… With foam latex, I’m not sure, but I didn’t want to take the risk. I then smoothed over the hairline joins with plaster, and used plaster to smooth over some ragged parts of the nostril, to reduce the risk of tearing when it comes to taking foam latex from the mould.

So here are pics of the outside and the inside of the mould.

casterinner1castouter1

This is now being left to dry for another day or two before I try and do my second ever run with foam latex… but this time, I’m confident I can reuse the mould for multiple runs, that the mould isn’t going to have to spend an hour in the over getting up to temperature to allow the foam latex to actually bake, and to be damned careful when I’m opening up the mould.

I was too eager. I’ll be more patient in the future. This *is a learning experience, and it’s fun… so don’t panic if this happens to you. Take a step back. Consider your plan of action. Make sure you have everything you need ready for use before you start… and maybe a glass of wine waiting for when you’re finished!

New Sculpt

Posted in Design, Fantasy, General, Horror, Masks, sculpting, Uncategorized with tags , , , on February 17, 2017 by Jim St Ruth
My new sculpt, which is now ready to be cast. The wider strip around the top and back, with the weird-looking bumps, is flashing, which will give me some room to trim down, so an area that can suffer damage both for the mould I’ll create and the final mask. The weird bumpy bits are pry points to cram a chisel into, to get the clay and the life cast out of the mother mould once it’s dry.
 
I’m now getting a little nervous, because this next step (moulding) has been my screw-up point before. *This time, I’ll not make it overly bulky. I won’t use a release agent either, because with Monster Clay that just seems to make the plaster for the mould drip off, allowing air bubbles to form.
 
I think that the thing is that, after seven months of working with Plaster of Paris, I just don’t like it as a material. Its sets too quickly, and my anxiety makes me panic, hence one of the reasons for the screw-ups.
 
So: planning, taking it slowly, don’t make the mould too massive, apply two layers of Plaster of Paris so I can work with it as it’s still a fluid, and apply modroc bandages between the two layers to add strength to my small-mass mould.
smaller1
I’m now working with foam latex, rather than liquid latex… so my last mask failed because my mould was so huge that the latex didn’t cure in the oven. The bake time is 2-3 hours, and I realised that a lot of that time was spent just getting the plaster mould up to temperate… Hence the planned smaller-mass mould this time.
My fingers are so over-crossed that I think I might need surgery.

Mask V2: Paints, Casting and Varnishing

Posted in Design, Fantasy, General, Halloween, Horror, Masks, sculpting, Uncategorized with tags , , , , , , , , on September 27, 2016 by Jim St Ruth

Here’s my finished second mask, painted and varnished!

mask1jimstruth2016

Bob II, as he’s called, was cast in liquid latex in a Platsil Gel 25 mould.

Contrary to popular belief, it’s perfectly possible to cast liquid latex into silicone, but there are some things to be aware of:

  • As there’s no porous plaster mould to absorb the liquid latex’s water, it will take a long time to cure and dry. Bob II took a whole 48 hours in a well-ventilated room. I left it in my work area over night with the window closed, and there was very little change to the curing process by morning – keeping the window kept things moving along.
  • Smaller areas, and areas where the latex has been applied more thickly, will take longer to cure… So, whilst the main body of the mask is fine, you can peer into those horns and see that the latex is still a very obvious white. It will cure. Just leave it be. Don’t be tempted to look; you’ll separate cured latex from non-cured… although this can give you some nice severed horns with suitably ragged edges. Just be careful!
  • The liquid latex won’t work with silicone with the dwell method of casting. Since there’s no plaster, you won’t get a skin forming around your negative. It’ll just sit there. Instead:
    • Get your liquid latex and add some latex thickener – check instructions on the bottle for the right amounts, as too much will just slow the curing process even more.
    • Pour this latex into your mould, but don’t worry about filling it up to the top. Just use a decent amount so that you can slush the latex around in the mould. Swish it around so that it gets to cover every part of the mould, then drain it into a pot.
    • Leave it thirty seconds.
    • Drain it again into the pot. What we’re looking to avoid is pooled latex, which will cure much more slowly. You don’t need to worry about it being a very thin coat. Just be aware of it gathering, and try to drain it. If it does pool in areas that are hard to drain, or there are areas that refuse to be coated, don’t worry. For the pools, use a cotton bud and gently spread the latex out. Don’t push the the latex so that it touches your negative, as this will drag on any latex skin and mush up the detail you’ve spent so much time sculpting.
    • Leave it 5 – 10 minutes. You’ll most likely see gaps in the latex, where the material’s surface tension has pulled the latex away from the underlying silicone. Don’t fret! Leaving the latex for those few minute will have started the curing process a little. It’ll be thicker, but still soft, so don’t touch it!
    • Repeat the process of swishing with liquid latex, sloshing it around so that everything’s covered. My castings have been fine at this point. Those gaps in the latex have disappeared, and everything’s been covered.
    • Drain back into the pot and leave for another while – 15-20 minutes.
    • Repeat the process 3 – 5 more times. You won’t really be able to gauge how thick the latex is but, as long as you’ve not sloshed it around the edges of your positive too much, it should be nice and thin there, and thick enough on the rest of your mask.
      • You’ll need it thin around the edges to blend the mask into your skin – I haven’t blended the mask at all in the picture, it’s just sat on my melon.
    • You might get ridges that do appear to be thinly covered, just dip a cotton bud in latex and lightly drag the bud over them. This will cover them to your satisfaction, though you might need to repeat the process a few times.
      • Very thin areas on the interior of the mask (away from the edges) will tear much more easily when you remove it from the mould.
    • Leave the mask overnight, and carry out a quick visual check the next day.
    • The edges of the mask might start lifting away from the silicone. Lightly dust these edges with baby powder to stop the latex sticking to itself if these edges start dipping inwards/ folding over.
  • The mask is ready to remove when all the whiteness has vanished. Brush the inside with baby powder again, and gently tease the mask out of the mould, limiting how much you pull. I’ve found teasing it out and lightly brushing at any stress points with a large, soft makeup brush that’s been dusted with baby powder helps a great deal – again, it stops the latex sticking, and the bristles will help detach the latex from the mould in a very gently fashion. Work with the shape of the mask, not against it, and don’t hurry! Take your time!

A Quick Note on Painting and Varnishing

I used acrylic paints in an airbrush, thinned with acrylic thinner for air brushes. You can use water as well, but that tends to make it much thinner, and getting that particular mix right is difficult. If you spray with it being too fluid, it’s easier to get unwanted spatters.

I didn’t bother sealing the mask first, which is fine, but there’s another note for caution. If you don’t seal it and your airbrush is at a higher pressure, it will blast into the mask, creating little tears and open bubble formations. You can choose to seal with a 50/50 mixture of Prosaide (a medical-grade adhesive) and water. Apply this gently with a sponge, to prevent unwanted stippling and brush strokes on your mask.

The finished paint job will need sealing, as although the acrylics will stick, if you accidentally scratch them, they will peel. The acrylics will also be liable to damage by UV light, making the colours fade over time.

Varnishing works to solve this. Both Liquitex and Golden make varnishes for acrylics, in both matt and gloss. Just make sure you get one that sets to transparency. They’ll make your colours really pop, keep your paint safe from scratches and stop them fading.

Bob II was varnished with Golden Polymer Medium (Gloss) in a thin layer.

You can clean your brush with plain water if it’s still wet, too – bonus!

Monster Mask Update

Posted in Uncategorized on August 7, 2016 by Jim St Ruth

A quick update with the holes for my eyes, nostrils and mouth cut out of the latex.