Friday, June 5, 2009

Casting the ATHENA engines

After completing the engine, I prepared it for molding and casting.
First I added three little "legs" on which the engine can rest when pouring the silicone.

With these legs the engine is a few millimeters above the ground.

Next I began to build the box for the mold.

To save silicone, I tried to make it as small as possible.

I sealed it off on the ground with some clay that is silicone resistant.

Then I sprayed the actual engine with some mould seperating agent.

And prepared the silicone.
I made very good experience with this 1:1 mix silicone from my favourite shop ( which is very easy to work with.

First i poured the lower half and again I used the clay to make some alignement marks.

Once it cured I did some cleanup (removing the clay, as well as some stray silicone on the model).

Then I applied some siliconeform seperating cream, to ensure both halves of the mold will later seperate easily.

Then I enlarged the box, and poured the other half of the silicone.

The silicone cures rather quickly so after two hours I removed the box.

Then I seperated the two halfs of the mold.

The model seperated easily and without damage.

Then I used some more clay to close the three small holes form the legs.

And prepared the resin.
This can also be found at Ria-Ro ( Again, since it is a 1:1 it is very easy to handle.

So I poured the first half of the mould (and some excess that I had into the other half).

Once the first half was cured, I poured the second half - applying a thin fresh coat on the first half.

And then I placed the first half on top of it.

And put som rubber bands around it to keep everything in place.

After two hours everything was to be cured and I started to remove the mold....

Unfortunately the resin is allready a bit aged (more than 12 months), and it seems it either didn't mix completely, or it simply didn't cure anymore....

Oh well.
At least the mould is working properly and I can try again. I will give it another try tonight with the same resin and hope that I just made an error when mixing, or if it fails again, I will have to order a new batch of resin....cross your fingers for me.