Foundry Casting The Space Ship Saucer Section

After casting my aluminum star trek insignia I have decided to use it as a base stand for my next casting that is Cheyenne Class (star trek ship 1/1400 scale).
In the next images you can see step by step how I made a sand mold for the ship saucer section.
This project I am planning to make in two flasks one for the saucer section and the other flask I plan to cast 6 remaining parts in one go.
This was also the first time I used my new aluminum sand rammer that I made.
The pattern I used is a solid plastic resin so I had to make it from one part instead of two halves.
It is very easy with an object that is relatively flat all I had to do is clear the extra petrobond around the pattern and then cover it by filling the cope part.
As for the sprue I used my babys wooden toy, it was perfect for this job.
To prevent any molten metal over spilling on top of my sprue I used a sliced tin can (see image).
I couldn't wait to open my flask and see how it looked but I had to let it cool down for 30 min.
When I opened it I was delighted to see that the mold was full with very little porosity on the top saucer section and in a few more places but nothing that will effect its apperance.
After all it is a space ship and there are many klingons and space debris out there.
After cutting off the extra aluminum from the sprue and vent holes I did a bit of grinding and sanding and it started looking really good.