June 6, 2000, 11:44 PM | #1 |
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Tonight was my first time I've casted since college (almost 2 decades). Beeswax was used to flux the lead (from wheelweights) and a short while after fluxing, stirring, scimming and casting a few bullets, a new layer of scum would form on the surface. I found myself repeatedly scimming (and sometimes fluxing & stirring). Is this normal?
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June 7, 2000, 12:31 AM | #2 |
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Oh. Fluxing. I thought this was an adult subject thread.
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June 7, 2000, 12:43 AM | #3 |
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I usually fluxed about 3-4 times per hour. You'll get heavy dross at the top more frequently if you're running the alloy too hot--that tends to burn off the tin too fast.
The scummy layer like sorta like the skin on uncovered pudding left in the 'fridge is tin burnoff. Just dirt-type dross is frequently crud mixed in with your dirty lead source. Love that smell of beeswax, and even of ordinary paraffin, and the gentle aroma of hot metals! Remember to ventilate! |
June 7, 2000, 04:59 PM | #4 |
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Yup every 10 to 15 mins. Its necessary even with a bottom pour furnace to put the tin in the scum back into the alloy. I use some of my bullet lube and it works but its smoky. I have a tube of soldering flux that I had out of a cheap soldering gun kit and it works a lot better. No smoke and the results seem to be better and last longer but its slowly running out. Possible I can get some like it at a welding supply shop.
------------------ Carlyle Hebert |
June 7, 2000, 08:29 PM | #5 |
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Soldering flux at most hardware stores and radio shack.
------------------ beemerb We have a criminal jury system which is superior to any in the world; and its efficiency is only marred by the difficulty of finding twelve men every day who don't know anything and can't read. -Mark Twain |
June 7, 2000, 09:25 PM | #6 |
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Years ago I wondered what different fluxing made so I used a single cavity mould, saved all my bullets in their as cast order, fluxed every 15 minutes and then constructed a weight curve of all the bullet weights. What I found was that the fluxing interruptions invariably cause weight losses in the bullets cast immediately after the fluxing was done and that it took 5 to 10 minutes for the weights to restability. I haven't fluxed since.
During casting you want a temperature consistency. That is the most important thing. If you have to flux do it at the beginning or end but not during a casting session. Don't believe me? Just do the experiments I described and you can see for yourself. Truth is that I didn't at first believe it either so I did that experiment several times. Eventually I was convinced. |
June 8, 2000, 01:50 PM | #7 |
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Ken do you think that the reason for the weight loss may be because the alloy has a higher tin percentage in it right after fluxing? More tin and less lead equals less density.
------------------ Carlyle Hebert |
June 8, 2000, 04:39 PM | #8 |
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I agree with Southla1. The weight difference is because you have put the tin back into the melt.
Paul B. |
June 9, 2000, 09:08 PM | #9 |
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I'm absolutely positive that the weight difference was due to mould block temperature. Linotype is a eutectic alloy. One property of such alloys is that it does not separate and hence fluxing does not recombine the metals in the alloy.
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June 9, 2000, 10:46 PM | #10 |
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I too flux my alloy about every 10 to 20 minutes. I use Marvelux instead of bee’s wax or paraffin.
I usually cast at a temperature of 725 degrees F. Running the temperature too high will surely burn off the tin in your alloy leaving your bullets softer as time goes on. |
June 11, 2000, 07:49 PM | #11 |
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I've fluxed with surplus candles (assume parrafin-based) without problems for lots of years. Fluxing cleans the melted metal mixture and returns lead oxide and tin/antimony/arsenic to the melt--it is considered necessary. Whether it alters the mass of the cast bullets I cannot say.
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June 12, 2000, 04:14 PM | #12 |
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As you well know, fluxing with waxes, greases etc. can make a lot of smelly smoke in a hurry. My solution is when it starts to smoke, light the fumes with a match. (I use a BIC) It doens't get rid of all the stink, but it does cut down greatly on the smoke.
Paul B. |
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