April 19, 2003, 09:50 PM
I casted up a bunch of mini-muffin ingots today. I guess I need some clarification on the fluxing process. I thought that the grey skim on top of the alloy was returned to solution by the introduction of flux. I added some candle wax and it ignited, leaving the skim dirtier than before the wax was put in.
Is the stuff on top suupposed to go back into solution or am I supposed to skim it off? If I am supposed to skim it off, am I taking away tin/antimony et al, making the lead softer?
Is it common to have to flux your small casting pot when casting bullets?
Thanks for the help!
April 20, 2003, 12:37 AM
I just posted a comment about your question on Lubrisizers, and now I see this question, so I will give this a try also.
My comments will be based on the assumption that you are starting with a basic alloy of lead, tin, and antimony which you probably are if you are starting with wheel weights for a base. If, on the other hand, you got some exotic concoction that contains other metals, my comments will not be appropriate. It is always good to start with a basic lead, tin, antimony (LTA) alloy.
When you melt your LTA alloy, the mixture will slowly get hotter. If nothing is done, eventually the tin and antimony will start to rise to the surface and will appear as a discoloration on the surface. Dirt and other impurities will float on the top of the alloy and should not be confused with the tin and antimony.
When you fluxed the mixture with a chunk of candle wax, you should have used a casting lade to stir the mixture (dirt and all) very thoroughly for a minute or so. At that point, the wax should have been consumed in the process, and all the discolored surface material should have disappeared back into the mixture - leaving a surface that is bright and shiny like a mirror. The dirt and residue that remains on the shiney surface should then be removed with the casting ladle, and then the casting process can begin.
If you use the ladle to stir the mixture a little each time you fill the mould, you can cast quite a few bullets before the tin and antimony start to rise to the surface again. Once you see the surface of the mixture is no longer bright and shiney, it is time to flux the mixture again. When using wax for fluxing, allowing it to ignite makes for less smoke in the process. However, you must obviously be aware of fire hazards in the area.
No, you do not want to remove the material on the surface of your alloy that is making it discolored. That is the tin and antimony you want to make your alloy hard. You want to flux, mix it up so the surface is bright, and then remove the remaining dirt and dross. Never remove dross and dirt unless the surface of the melt is bright and shiney.
I am not sure what you mean by "Is it common to have to flux your small casting pot when casting bullets?" However, as mentioned above, you have to continuously flux your mixture as you cast bullets and refill your pot.
April 20, 2003, 01:41 AM
A must read for a bullet caster.
Paul "Fitz" Jones
April 20, 2003, 02:07 AM
In fluxing commercially in my 3 ton pot I used a flat bladed shovel and scraped the sides of the pot as dirt seemed to migrate to the sides. On the average 12 to 20 pound home pot I used a old tablespoon sized spoon held in a pair of vise grips and when burnibg the candle wax I also scraped the sides.
With me it was important to clean the lead scrap in another furnace than my final casting pot so only the cleanest lead went into the final pot. Even so I still fluxed as described when there was a mayo type material on the top or skein as it is called by old timers. The candle wax will put the mayo back into solution but what should be left is a dry powder that can be skimmed off.
My scrap yard used to buy it from me as they said it contained trace amounts of gold, silver, arsenic and other metals that would not melt at lead casting temperatures. Dispose of it safely as it can be poisonous.
Clean lead is needed for identical weight beautifully filled out bullets that you can win a match with.
I hope this helps
April 20, 2003, 02:39 PM
Great reading JackM! I love hearing about free-and-better than storebought, solutions!
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