Moldings

[Cestria]

Can anyone explain the different ways of doing molds? Let me explain.

If I want to make something then I can use a 3D printer.

However I can also take an imprint of something, tweak it and use a mold of tweaked object

I came across videos of people taking casts of faces and making masks from them and videos of people doing wood turning and putting liquid plastic in with the wood before they work on it.

So I am curious about what the different options for making objects and the advantages/disadvantages of them. Can anyone expand on this? Still searching the web but not really sure of what I am searching.

Thanks

[Alistair MacDonald]

Hi Cestria,

I think it depends on what you are wanting to cast. I do not do casting myself, but I do do a lot of 3D printing for those who do. In other words I know part of the process well, but only a part of it, and the rest I am no expert.

Most will take the 3D print and create a silicone negative mould from it, and then use that to create the final item. The exception to that is glassworkers who will use the silicone mould to create a sacrificial wax positive to create their final mold for the glasswork. If it is a one off some will skip that process and use a PLA print to create the mould for the glass, and smelt it out at around 400c. 

The plastic in the wood you speak of sounds like resin to me. You can do resin casting but I do not know anyone who has. It is smelly and not as safe as some YouTube videos make out. I need to work with resin for some 3D printing I do for the day job and it is not nice at all. If you are going to work with it my advice is to take the safety advice seriously. 

I think the problem with answering your question is that the answer is overly large. Casting is a huge subject. Perhaps the way forward is to start off with a project and find one way to do it and learn from that. Doing a project is probably the most popular way of learning here. 

All the best,

  Alistair

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[Simon Craig - Blue Oblong]

Hi Cestria,

I have cast numerous things over the years, in various hobbies.

There are many ways of casting depending on what you want to make and what you want to use it for.
I think you should start at that end rather than learning loads of the wrong stuff.
eg. There were a few people castling plaster castles for fish tanks, to later find that plaster affects the ph of the water so much that it kills your fish.
I am saying that there is more to learn (like this) than you might imagine, to learn about all of the methods of casting.
So what would you like to make?

Simon

[Andy Bennett]

Hi,

I agree with Simon that it's best to start with the end in mind and with a
specific thing you want to make. This way you focus only on the important
bits (for you) of a vast subject.

I'm no expert, but I learnt a lot from the "Guerrilla guide to CNC and
resin casting":

http://lcamtuf.coredump.cx/gcnc/full/

It focusses on precision resin casting for things like gears and robot
parts so might not be relevant to your use case, but it is well written,
goes into a lot of detail and might give you some background that will
allow you to research more specific things or suggest some search terms to
use for different parts of the process.

On the other hand, I've also tried taking moulds off of some household
objects to make a lamp using this process:

http://www.resin-supplies.co.uk/latex_mould_process.htm

http://www.resin-supplies.co.uk/info_latex_mouldmaking.htm




Good luck!

Best wishes,
@ndy

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[Cestria]

ok I will pop in on a Wednesday to introduce myself and explain what I am looking into. It is a project but I plan to dismantle it after a while as I don't have space to keep the things I am looking to do. Also anything to do with molds a long way off right now.