Introduction: Melting Aluminum and Brass Differences

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.

Comments

author
bill z (author)2016-09-06

When melting brass the temp can range from 2000-2200 degrees which is very close to the melting temp of steel. At that high temp those two metals bond which is why your having some problems. If you change to using a graphite crucible it can withstand the high temp and no bonding problems. Just some info to help further your project.

author
DuralM (author)bill z2016-09-08

Thank you very much bill z. Yes, you're right about graphite. I understand that it's better to use graphite crucible! I'll try it in the future. I had a problem because the temperature wasn't enough that's 100%. I didn't get 2000 F. I've just made a new casting, so crucible was white (so that's approx. 2000 F) and brass was totally melted. I'll upload my new results on instructables this week.

author
BeachsideHank (author)2016-08-30

Crucible choice becomes important at those temperatures too, steel may not be the best construction:

http://foundry101.com/What%20is%20Crucible.htm

author
DuralM (author)BeachsideHank2016-08-30

Thanks for your comment BeachsideHank. Yep. I agree that steel is not the best solution. I've bought some fire clay, so will definitely make experiments in the future. Is this your article on the link? If yes what proportion of fire clay do you use in fire clay crucible? I've seen in youtube that one man used 40 % of fire clay and 60 % of grog powder. I haven't seen silicon carbide in supermarkets and fire clay is much easier to get. Also graphite dust (powder) is available, so I'll try everything that I can.

author
BeachsideHank (author)DuralM2016-08-30

Link is not my work, but I refer to the site often as I have a home shop foundry melting aluminum. Some day I too will go up the heat index to copper and brass but am just warehousing my scrap finds of them as of now.

author
DuralM (author)BeachsideHank2016-08-30

Ok. That's right. I also have a lot of aluminum scrap as well as brass and copper. I tried to melt brass just after aluminum. I was curious If it would be much harder. The next I'll try is some mold casting.