Converting Aluminium Scrap into Ingots

[Meldonmech]

 Hi Guy
           Over the weekend I decided to convert some aluminium scrap into ingots. Everything went well until a door handle I fed into the half full crucible went in at angle and the top part fell down into the gap between the furnace wall and the crucible. This then went white hot, set on fire and poured out of the gap around the burner entrance hole. I manged to extract the crucible, but when I removed the dross onto the ground it started to glow white and explode. I suspect the door handle contained some other additives. From my chemistry lessons at school I recall magnesium and phosphorus burning like that during an experiment.

               a) Can anyone verify my conclusions
               b) Has anyone else had this experience
               c)  How can one identify this metal
                                                                                    Cheers David

[awemawson]

I had it once is almost similar conditions. I'd poured a casting using unknown scrap, then went to scrape out the dross from the still glowing crucible, which burst into exciting flames. I just covered it with floor sand and left it to sort itself out. My conclusion at the time was the same as yours - the scrap must have contained a certain amount of magnesium, which ignited when the dross was exposed to the atmosphere.

[Pete.]

If you watched that program about the two towers monday night you'd have your answer. White hot aluminium introduced to water (from the ground in your case) makes hydrogen gas. It's all explained here at 28 minutes in:

http://www.channel5.com/search?utf8=%E2%9C%93&q=Twin+Towers%3A+The+Missing+Evidence

[Meldonmech]

  Andrew and Pete thanks for your posts, I now believe that some items of scrap had a magnesium content, and seem to now recall, that I somewhere I read of the dangers of melting scrap magnesium car wheels.
       The tower video was very interesting and I had missed it.  The night before I did my casting it had rained, and the ground on which the dross was emptied was damp concrete, and this contributed to the explosions.

The only unresolved problem is how to identify aluminium/magnesium alloy, as I have not come to any conclusions. 

                                                   Cheers David
   

[JD]

David, I was told to use vinegar, bare he metal and pour a few drops on and if it foams it contains magnesium, I have never tried it.
John   

[Meldonmech]

Hi John

                        Thanks for your post, I tried the vinegar test and there was no reaction, but I now think the door handle was magnesium bronze.  When I ground a flat on the remains of the handle to do the test I noticed it was a pale bronze colour,  I then roughly weighed it in my  hand and realized it was much heavier than aluminium alloy. I looked up the uses of manganese bronze castings, and my handle fell into that category. The melting point is in the range 865c to 890c which is easily achieved in my furnace. Originally when I looked at the handle it had a bronze tinge to it, but I thought it was aluminium that had been laquered.
                    Well now I know what happened and why I will be more vigilant in future.

                                                                Cheers David

[Manxmodder]

As we are on the subject of aluminium casting has anyone here read the book Casting Aluminium by C.W.Ammen?

It seems to have good ratings and is highly commended by those who have it.
I'm thinking of ordering a copy but would be interested to hear opinions of other Madmodders.
 Are there any other books on aluminium casting you guys would recommend?......OZ.

[mcostello]

Yes have read it, several times over the years. Best to see if a copy is available at a local library so to save funds for more tools.

[Meldonmech]

Hi Manx
                   I have not read this book, I have learned most from watching the video's of Myfordboy.  He has videos on you tube, and you can also buy CD's from his website.

                                                                  Good Luck  David