Trace On!

So last weekend I came crashing at zen's workshop while shouting

"Do you have enough material king of pandas!" While doing so I was focusing on charging up my magic circuits

"Ora!" as I leap forward I have fully flipped all the switches of my circuits

"Magic Circuit Fullcount! Marble Phantasm!"

How...
How....
How.....
......
.......
"How the hell did I turn into a mahou shoujo!..."

Well what actually happened was, we just "planned" to do a project but ended up "finishing" it in 2 days...

---

So that project we planned to do was to make a silicon mold to recast a certain part. So basically yes we are "tracing/faking", and so we took our first step down faker road. So to commemorate our first step, we have documented the steps we did, and share it in this blog. But before that we here is a brief introduction about silicon molding

So first we pick the part we want to make a mold out of, then there are several considerations before we make our mold.

1. We need to determine whethere it is a top gate or an under gate.





UNDER GATE
- Produces a very smooth and uniform pouring of material, and minimizes introduction of air bubbles
- More silicone is needed to make the mold

TOP GATE
- Ideal for rapid curing material
- Uses less silicone
- But due to the design air can get mixed to the material during pouring and may cause air bubbles to form inside the cured part

2. We need to orient the part where in there will be no undercuts.






- Undercut is a feature/part of the original to be re-casted that may lock the original or recast in the silicon mold
- Repositioning the original or cutting up the feature, making the original simpler in design may eliminate this problem
- Shallow undercuts are usually not a problem as the silicone is flexible enough to pop out of them

3. And lastly we need to design our mold to prevent or avoid traping in air after pouring






Since we are just pouring the material and we are working with gravity contrary to injection molding (where resin can be injected/pushed into the mold with pressure forcing air out) we need to take note how to avoid trapping air inside the cavity when we are pouring the material

For a more in depth explanation you can visit my source: Dan Perez Studios
He was able to write a great article about silicon mold making. I was also able to make a "paraphrased" and shorter version of my own but I think it is still better to give his article a read.

---

So for our actual trial here are the pictures:

We first set the part we want to make a mold of on a bed of roses... wait I mean clay. We also provide a passageway for our rein to flow and a reservoir. It is also important to have a smooth contact between the parts and the clay for a finer mold lines

After finishing the clay bed, we now form arms and legs, and I'll form the head... wait what!?... OH! the case or box! So the box is made from acrylic boards and then fixed together using a glue gun or hot glue. Then we ensure that the case will not have leaks by adding clay to the edges.

So here we now pour the silicon as thinly as possible to be able to burst out bubbles created during mixing of the silicon.

And here we wait for the silicon to cure/dry/solidify, which in this case was very fast... around 2 to 3 hours contrary to my source saying overnight. It may be because we added a little more catalyst or maybe a different blend compared to my source. But we still let it sit overnight. As for the mixing ratio of the silicon, just follow the manufacturers instructions since it may vary due to the type of blend.

Then the following day we removed 2 sides of the box to be able to take the part out.

We then remove the clay bed, flipped the 1st half of the mold, gave the mold a bit of retouch with clay, and then brushed some petroleum jelly to prevent the 2nd half of the mold from combining with the 1st half.

Pouring of the 2nd half

Waiting for second half to cure

After curing we disassembled the box and separated the 2 molds apart, and viola we now take out the original and the passageways.

Here we now put the 2 molds together and is held by several rubber bands, to make sure that there are no leaks we tried filling it up with water and observed the sides for leak. If a leak appears try adding some more rubber bands. Make sure you don't clamp the molds to tightly, to the point that there is severe deformation since it may also affect the cavity inside and the final product itself.

So here we tried pouring in some clear resin and the final product can be examined better in the next picture.

So here you can see that the final product is so fugly... in conclusion we made a major mistake due to over excitement we forgot basic rule #3. We had poor positioning and so trapping air inside the cavity. But we will still try to make the mold work but that will have to wait.

For any comments, questions, laughter, violent reactions please feel free to write a comment below. And I'm off to bed.