March 6, 2011, 05:40 PM | #1 |
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Help Me Please
Ok so i have been interested in casting for years now. So I went to my local reloading store to pick up some primers that had come in. Not only did i get my primers but also lymans cast loading book. Since it was on sale and all. Just went back today and picked up a Lee 4-20, 2 molds for 9mm and a few other dodads. Got home and went straight to setting it all up. Cleaned and smoked the molds per the instructions and started up the production pot. Took me about 50 bullets to get the pour right so i didn't get wrinkles. After that everything smoothed out. But here is the problem, about halfway through it started to build a brownish red powder on top of my melt. Quiet a bit of it as a mater of fact. The mold was a 124grn bullet and they weighed in at 123.8 so what is going on?
Last edited by DocHoliday; March 6, 2011 at 06:12 PM. |
March 6, 2011, 06:36 PM | #2 |
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What bullet alloy are you melting? How hot were you running the melter?
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March 6, 2011, 06:39 PM | #3 |
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The alloy was pure lead, chilled shot and tin solder. The temp was right around 700-F. The alloy was mixed by a friend of mine it's somewhere between hardcast and lyman #2
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March 6, 2011, 07:33 PM | #4 |
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That's called dross and you're going to get some on your melt. Don't worry about it. It does have some bad stuff in it, so ladle it off the top of the melt and dispose of it. I normally keep a small can (think coke can with the top cut out.) beside the melter and when I add metal and flux, I skim off the dross and put it in the can. After three or four session, the can will get full and I throw it away.
A more technical explanation of dross can be found here. LINKY! Metal that's real dirty is going to have a lot of dross. Metal that's clean, not so much. It's part and parcel of the casting process and we all have to deal with it. |
March 6, 2011, 08:43 PM | #5 |
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At a loss
So i drained my pot thinking it was just a dirty alloy. Put it into a cast iron pot remelted fluxed and cleaned the whole lot. Put it back into my production pot to cast some more. Low and behold not 20 min in it starts crusting up. This is not a light crust it's like I am pouring brownish redish green sand on top of the melt. It's starting to perplex me it didn't do this outside of the production pot so what am I doing wrong.
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March 6, 2011, 10:28 PM | #6 |
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Fluxin material
Doc
what are you using to flux with ??? I use parrafin wax or a DRY stick , anything to induce carbon into the melt ! Plese don`t melt your dirty wheel weights & shot(recovered??) in the Lee pot , do it in a seperate steel or iron pot & ingotize it ! Alot less chance of causing problems in the melter !! In the melter I do a last fluxing & leave it on top to create a O2 barrier , but pull it off before adding sprues back to the pot . PS: if ya try parrafin be advised it either smokes alot or will ignite !!
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March 6, 2011, 10:51 PM | #7 | |
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March 7, 2011, 09:57 AM | #8 |
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Thanks All
Think I am just gona scrap it. I have some true hardcast alloy i'll give it a shot.
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March 7, 2011, 10:58 AM | #9 |
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I wouldn't scrap it.
If you are getting good boolits out of it after correct and thorough fluxing, who cares what is floating on the top of the melt? It's just dross. If it really bothers you, after you flux, put a layer of kitty litter on top of the melt, and you wont' see it. |
May 21, 2011, 04:07 PM | #10 |
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The brown stuff on top of your melt is dross. The tin is drossing out, because you are melting too hot. At 900F most of the tin in a 5% tin alloy will dross off in thirty minutes. Be aware that Lee melters have a thermostat but nothing to tell you what the temperature is. I have tested three of them with a thermometer of proven accuracy, and at their mximum settings the temp is up in the 900 region. 900 is in the beginning of the area of fuming, and lead fumes are colorless and odorless.
I like and recommend Lee melters, but only with a separate thermometer like those offeed by RCBS and Lyman. I also suspect that you have too much tin (bar solder) and that your alloy i too soft (no antimony). Tin does little to harden lead, antimony is the hardening agent. Bullets weighing more or less than nominal weight means nothing. In fact 123.8 from a 124 grain mould is amazingly close. Because of manufacturing tolerances there can be considerable variance in moulds. In fact you can assume that of ten identical moulds you will get at least two grains variance, and it will be unlikely that more than any two moulds will cast the same weight. I have two identical Lyman moulds that cast four grains different. |
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