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View Full Version : Smelting question, is this normal.


TheDoctor
03-05-2014, 01:27 PM
98676Have been smelting larger ingots of various alloys. Some COWW, mostly range scrap, and today, melting down 5 lb ingots of lino. Goal is to put them all into 1 lb ingots. Maintaining a melt temp of 700-710, fluxing with lizard litter. Getting what looks like a lot of brown sand on top of the melt after the second or third time stirring, even with the lino. Lino is not in it's original ingots, bought it from a member here, and it has been recast. I know some of these ingots are not the cleanest on the outside, but this "sand" is more than can be accounted for for the quantity of sawdust I'm using, and that stuff normally leaves visible ash after it chars off.
Springfield
03-05-2014, 01:33 PM
I usually only get that reddish/brown dirt looking stuff when I melt down older roofing flashing. It is some of the dirtiest stuff to do, but you end up with some nice soft lead. There really shouldn't be any with Lino, or even WW if they have been smelted before, at least not in my experience.
runfiverun
03-05-2014, 01:48 PM
that looks like some severely oxidized alloy you have there.
I'd re-run it and this time make some fire on top.
combine the sawdust with some burning candle wax.
one is for carborization and one is a reductant of the oxides.
tengaugetx
03-05-2014, 04:59 PM
Could it be tin or antimony oxidizing from too much heat?
TheDoctor
03-06-2014, 08:51 AM
Refluxed with more sawdust and wax. lit it on fire, stirred the dog out of it. Three times. It helped a little, but still filled a soup can with crud off of about 60 pounds.
Sasquatch-1
03-06-2014, 08:58 AM
Check your bag of Lizard Litter. If it is desert mix it has sand in it.

I bought a 1 pound tub of soldering flux at Lowe's and us it in my final melting when I am casting. It seems to get everything mixed back in and makes the alloy nice and clean. It only takes a dab.
TheDoctor
03-06-2014, 09:19 AM
Does not say anything about desert mix. All it says is it contains lab grade aspen chips. Would be funny, me wondering about sandy stuff, and putting sand in there to cause it!
Lefty Red
03-08-2014, 09:56 AM
that looks like some severely oxidized alloy you have there.
I'd re-run it and this time make some fire on top.
combine the sawdust with some burning candle wax.
one is for carborization and one is a reductant of the oxides.

I had a batch of printing dies from the scrap yard that produced the same. I fluxed twice with wax and pine chips and really helped out. But you will have about a third or less of "skim" after you do this as oppose to what you have now.

Lefty