Annealing copper and brass

I have turned commercially made brass and aluminum rod as well as aluminum rod that I casted for making small parts on my wood lathe. Yes I know that I shouldn't turn metal on a wood lathe.
I recently cast copper and brass into rods. The copper was from clean electrical wire and the brass was clean plumbing brass. The cast brass and copper rods were so hard that the chisels barely made a scratch. I attempted annealing them but it barely made a difference. Based on my research annealing is heating to a cherry red and quench. I accidentally heated to orange,lowered to red and kept at that temperature for about 20 minutes since the rods were 1 1/2" in diameter.
Is there anything that I can do to soften them so that I can work with them? I would really appreciate any help. This post is long but I tried to include as much information as I could.
Thanks

 

There could be a hard skin on your castings, there could be aluminium contamination from your crucible: aluminium bronze is quite hard and not much aluminium is needed which is why it's a good idea to have a separate crucible for aluminium and copper alloys. I recently cast some brass bar and the only issue I had was a hollow shrink defect in part of the bars, it machined beautifully.

https://forums.thehomefoundry.org/i...-brass-today-from-scrap-zinc-and-copper.1882/

 

Mark
Thank you for your reply. I used a new crucible that had never had aluminum in it. I only used it for brass and copper.

You mentioned that it may have a hard skin on it. Is this a separate problem other than aluminum contamination? If so what could have caused it and how can it be resolved? I have a lot of metal in these rods and it would hate to discard them.
Tom

 

David, thank you for your reply. The reason that I joined this forum is because there is so much incorrect information out there and you guys actually do it.

I had read that heating ferrous metals and quenching hardens them and heating non ferrous metals and quenching or cooling slowly softened them.

Is there a way to soften the rods at this point? Anneal again and cool slowly? Since the rods are like 1.5" in diameter I am not sure how long to hold at temperature to assure that they are heated all of the way through.
Tom

 

I have done a lot of model boiler work in copper.
You cannot harden copper by quenching. it will always be soft after heating to red wether it's quenched or not.

 

Myfordboy thanks for your reply. I have watched several of your UTube videos.
Do you have any ideas as to why my annealing didn't work or why they were so hard after casting? Is it possible to overheat during annealing. Any ideas on how I can effectively anneal at this point.
Tom

 

THash
All you can do is heat to red and let it cool. I would expect it be annealed then.