The Energon Pub

My questions are simple.Does anyone know how to create a mold so i can reproduce plastic parts and from what material should be made to withstand melted plastic?And how do you remove the created stuff without damaging the mold so you can use it consecutively?

In art class, we used silicon for the mould. You have a square box (wood), start filling it up with silicon, place the object in the silicon.

Once cured, cut the silicone in half, create a whole to pour your material through. Hold the mould together with rubber bands or wire or string.

We made candles, so we poured hot wax, tap the mould to get the air bubbles out. Don't forget the wick, but if you're not making candles, that won't matter.

Once the wax dried, take off rubber bands and pull the item form the silicone. Shave off the lines make from the joining of the moulds.

I would assume that this would work for plastics. Cured silicone is pretty indestructible. However, I don't know the temp to melt plastic vs temp to melt silicone.

Also, this was for one large mould, I'm sure it can be scaled down for smaller parts. Just remember, that melted plastic is a carcinogen, so work in a well ventilated area and wear a breathing mask.

I've entertained making TF parts this way, but never got around to it.

Yeah but TF's are made from injection molded plastic into iron molds right?

I've been thinking about experimenting with silicone molds and resin/epoxy plastic pieces.

Thanks for the tip,sounds interesting-if i won't die from cancer that is How did you inject the wax into the silicon?I assume that the hole was small,no?

1)
| |
| |
|______|

2)
| |
|__CD__|
|______|

3)
|______|
| CD |
|______|

4)
________
| |
| CD |
|______|

5)
___V___
| | |
|C | D |
|__|___|
V

6)
___V___
| _|_ |

|__|___|
V

7)
_______
| |
>| () |<
|______|


OK,
1. Empty mould.(Horizontal View)
2. Filling mould with silicone and placing object(CD) in.(HV)
3. CD with silicone over it(HV)
4. Mould is filled.(Top View)
5. Mould has cured, cut in half. (TV)
6. Mould cut in half, CD removed.(TV)
7. Hollow mould, ready to be filled. Hole on top to pour.(TV)



*EDIT*
It looks right in preview and as I'm writing it, but once it's up, everything get's mopved to the left?!?



*EDIT*
Maybe I got it correct this time.

Nevermind. Good idea, poor follow throw.

Thanks a lot I hope it works because the parts i want to create are roughly 1 inch big that's why i asked you about the hole.

It would help if we knew what you were trying to create.

pieces from strategy games miniatures

I'm trying to master parts replication myself; I use liquid latex as my mould material.

I basically make a small 'box' from card (usually just old cereal packet card does the trick), consisting of four strips for the sides, and a base piece. I use hot glue to fix the pieces together, then fix the component into the box. If I just want a simple one-piece mould, I'll just hotglue the original straight into the box. Then I'll pour in thin layers of latex, letting each part-cure for a few hours before adding more. Once the last layer's sufficiently cured, I can turn out the original, but I'll leave the mould to properly for at least a day or two to be sure before I use it.

Two-part moulds are trickier, but I'm getting the hang of them. I'm basically using the same technique, but in order to get a flat surface on the first half, I'll cut a gap in the card base to accommodate the orginal, and let it sit halfway through (basically so the card runs where you want the mould line); then I'll hotglue the component in from the bottom. I'll add a couple of blobs of glue inside the card base to act as locator lugs. Then I repeat what I did for the one-piece mould.
Once the first half has cured, I'll take apart the box, but leave the original in the latex, if I can. I'll build a new wall round the mould using more card and hot glue, then brush a layer of petroleum jelly all over the exposed interior surfaces of the mould (latex sticks to itself, so the jelly acts as a release agent so you get two halves of a mould instead of one mould with an original embedded in it with no way out). After that, I'll repeat the process with the latex, adding layer after layer.

--EDIT-- By the way, if you want to see what ConDrewfus was trying to show you, hit the Quote button on his post; then you'll see the diagrams as they were typed, with the spaces where they should be.

The whole process sounds more complicated than i expected...maybe i'll drop the idea
Thanks for the tips anyway

I haven't tried silicon, but the latex moulding I described isn't actually that complicated, just time consuming (and most of the time it consumes is when you're waiting for layers of latex to cure). Put in simple terms, it's just:

1. Build a simple box or tray to form the outside of the mould.
2. Fix the original/master into the box.
3. Pour latex in thin layers, allowing each layer to part-cure before adding the next.

Nevermind Ramrider, it's not any better that way either.

Also, it is easy to make a mould, you just have to wait for everything to cure before going ot the next step.

The mold is easy,the proccess of melting the plastic and injecting into the mold seems difficult-especially when you want to make 100 pieces

Ah, right, you want to reproduce large numbers of parts. Frankly, I don't think there's going to be any quick way of doing that on a kitchen-table scale, much as I'd also love it to be the case...