Today, I'd like to share my ideas about differences in melting aluminum and brass using charcoal.
Step 1: Enough Easy to Melt Aluminum
First of all, I want to mention that it was enough easy to melt aluminium from the first attempt but the situation was totally different with brass.
The hardest thing is the temperature. We should remember that if for aluminum we need to get 660 °С (1220 °F), for brass we need to exceed 900 °С (1652°F). That means brass demands +250-300 °С (482-572 °F).
Step 2: My First Attempt in Melting Brass Failed
My first attempt was totally failed. I couldn’t get the right temperature. I added a lot of charcoal but the temperature didn’t increase. Therefore, charcoal and approximately 1 hour was wasted. Nevertheless, not totally wasted. I’ve made a conclusion that the problem was in the air supply.
I had to make my first metal melting furnace upgrade. I’ve made a new blowpipe which allowed to supply the air not only in one place but around the whole furnace.
Step 3: Temperature Scale for Brass
As I mentioned earlier I had to increase the temperature by 250-300 °С (482-572 °F). Therefore, if the crucible glow orange or yellow light that will be the evidence that metal is melted and ready for casting.
Step 4: Brass Melting Results
Finally, some brass was melted but I was able to cast only a small quantity of this metal. The crucible became red, in some places light red and several points became orange. Though, I’ve got some positive result, it wasn’t enough to melt the whole brass.
Step 5: Conclusion and Plans
I've decided to make the second furnace upgrade. My idea is to make blowpipe using larger pipe diameter. I’d like to use 32 mm (1 ¼ inches) instead of 15mm (1/2 inches). I'm sure that this is the main issue. I see that my vacuum cleaner can give much more air but it's not an equipment which can make some pressure. It's not so powerfull. When I use more appropriate pipe, of course using the same design as my 1/2 inches pipe upgrade, I'll get additional several hundreds degrees.