Snake lady made a stupid

[follox]

Hello! More snake-themed problems. The largest one, obviously, being that I'm more excitable than knowledgeable. But let me first address this specific symptom of that...

This is the one and only cast I got of Mr Wiggly. I destroyed the original getting it out of the split mould, and I destroyed the mould getting this cast out. And this one is glued back together, too Pretty, ain't he? *cringes*

So that didn't go so well, but I do really really want to recreate something similar. I have some (mostly) transparent silicone now so I think that will really help me see where to cut, but even so - I just cannot picture how it ought to be positioned and then what cuts to make to remove it.

If anyone can shed ANY light on the matter - literally anything, including 'don't even try it, you fool', I would be exceedingly grateful!

[rattrap]

I would be tempted to cut the model into 3 sections and make 3 separate moulds. Before you make your mould box, mark on the model your cut line so you can follow it when cutting if you are doing a split mould.

[mangozac]

It shouldn't be too difficult to do as a single part split mould. You really want to use a fairly soft rubber though - down around ShoreA 20 hardness.

The following pic shows how I would try it - viewing the mould from above. The cut line just follows the snake profile.

You will need gates and vents at each of the highest points when viewed from the side.

[follox]

Thank you both!

Magnozac, that's close to how I (tried) to do it the first time, but cutting blind into the opaque silicone was impossible! I also had real trouble around the part that's shaped like a U in your illustration (and thank you for that!) - that's a really deep loop, and undercut. Much appreciated though, it's good to a) know I'm not imagining it's possible and b) see a good reference!

Perhaps materials will help. is what I'm trying out now. It's pretty soft and I can at least see where I'm going.

The whole thing is only about 2" long, Rattrap, which is why I'm hesitant to consider multiple moulds. Will bear it in mind though!

Where the tail tip forms a loop, would you suggest cutting down one side of it so the centre piece of silicone forms a core that pops out the other side? That's one part I just can't get my head round!

[mangozac]

That silicone is extremely soft but should do the job. You might need to support the mould on four sides with boards.

The tail loop is no problem. Just stretch out the silicone on one side and then cut through it and the cut will actually end up closer to the middle when it stretches back.

Cutting blind into that depth can be difficult - what you need to do is follow the shape of the part. In any case the translucent silicone will help greatly!

[Squib]

Ok, so maybe I am going to make a fool of myself here. I have thought that this might be a potential way to do more complex 3 dimentional objects that branch out in more than 2 directions. Think of a tree with 3 branches in 3 different directions, and each branch again splitting into 3 smaller branches. What I would try is a multi part mould, much like a 2 part mould but use 3 or even 4 parts. Building up and removing clay around your Snake lady is in my mind far less stressfull on the object being cast than pulling a silicon mould off.

Your clay can be built up and lowered around all the small twists and turns leaving only a small part exposed and then you create the first mould piece, remember your keys and the shape will also assist as it will be it's own key. Then, with the first wedge mould and a bunch of clay, repeat the process to create a second mould piece. Rince repeat till you have all the wedges to complete the Snake Lady, each time with less clay and more mould segments.

The 2 main challenges I see are:
- Getting the keys to fit for the last segment when putting the mould together. This might be less nessesary if your wedges are "wavey" with high and low spots where they will naturally fit together.
- Getting the mould into the centre of your Snake Lady. With something like a tree, you will run the tree trunk in the centre of the mould being included in all your parts, removing that hurdle. In your case, the pictures seem to suggest that there is a void in the centre, something that will need to be filled with mould.

rattrap's suggestion may be the most simple for someone on their way to recovery but I welcome my addiction

[RageofAchilles]

Just a little tip on keys for multi part moulds. I have tried a few methods over the years. The best keys so far are beads! I use several different sizes set in the clay to a 3rd of thier diameter.

What you end up with is self locking moulds , because the spherical shape the beads made locks into its negative on the other mould half. Some of my moulds don't need to be bound when I cast, because they lock together so well.

[mangozac]

Honestly, what you're trying to cast isn't that complex - you definitely don't need a mould with more than two parts and I insist that it's possible using a single part mould if it's nice and flexible

[follox]

I'm going to try the split mould again now I have silicone I can see into, and your illustration and vote of confidence that it will be possible - but I am enjoying the discussion and the concepts I particularly like Squib's way of thinking - it seems similar to my own, ie slightly too much and possibly way beyond mark, but you know for sure it's going to be a fun process

Rage, I'm not sure I understand how beads would be better than poking dints in with the end of a paintbrush, for example. I'm not trying to be argumentative - but would like to try and see how your method would be an improvement, in case I'm missing something

I should point out that the snake lady I'm referring to is myself (I was picturing crazy cat ladies, but I don't have a cat ...). The snake in the photographs is Mr Wiggly

I do have a final purpose in mind, if I ever finish a project. Honest It's not actually a tiny snake army, though I tend to refer to it that way...

[RageofAchilles]

[follox]

Oh I see... Because they're undercut. Genius!

Thanks for explaining

So my wax arrived... Now I just need to summon the time and the courage to try again...

[mangozac]

Wow, that is cool! I didn't understand that's what he was getting at either!

You still need boards and rubber bands, right RoA?

[RageofAchilles]

[follox]

*POP*

Definitely trying this, if only for that reason.

[follox]

I don't want to clutter up another thread asking silly questions about not being able to visualise cuts, so I'll bump this again - sorry!

I often want to cast spiral shapes. Mangozac's description of cutting through a vertical loop was really helpful, but I can't picture how you'd do it if the loop/spiral is on the horizontal. I've tried in the past to cut along the spiral but they're a beggar to get out and I usually end up breaking the cast or the mould at some point - and you couldn't do that and continue the cut to the edge of the mould or you'd have bits falling out o_o

If anyone knows what I'm wittering about do they have any ideas?!