Pages

November 25, 2010

Today I casted aluminum scoop

I got some new scarp aluminum and my new propane burner was ready for his first test run. BTW I will post in the next few days how I built this propane burner.
I was amazed how quick the aluminum was melting in the crucible and it was a good opportunity to do some aluminum sand casting.
I looked around and I decided to duplicate my plastic scoop.
I used my large wooden flask it was just about the correct size. It takes about 10 minutes to make this easy mold. I used 2 rounded wooden toys to create the sprue and the riser, and my aluminum rammer I made to pack all the petrobond.
After my last few castings I realized that it is very handy to use one big clamp holding the drag, cope and base board tight together. The clamp also makes it easy to move flask around using the clamp as lifting handle. As for the pouring basin I used a tin can to avoid spilling molten metal over the wooden flask. I still have to give it a bit of cleaning and polish but the end result was very good. Now I have a new excellent aluminum scoop ;-)


Here is my video pouring the molten aluminum

November 08, 2010

Aluminum ship is finished

Finally all the parts are ready the next thing to do is grinding all the extra aluminum from the pouring. I used a grinder for cutting off the extra big chunks, metal chisel then sand paper (600 grit), after coarse metal wool and finally a fine metal wool. I could keep on polishing until it will look like a mirror but at the moment I am happy with the way it looks.
To attach all the parts I used a metal adhesive after all its just going to sit on the shelf. Another option is using aluminum welding or very small screws to attach all the parts.
I used the star trek insignia as a base for the ship drilling a 5mm hole for the metal rod.

Sand casting 6 parts in one flask

This is the second aluminum pour I made for the 6 remaining ship parts. I ran a bit low on aluminum for one part so I made it again in a smaller flask. All of the parts looking good now its time for a bit of grinding and polish before final assembly.

November 07, 2010

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.