Lyman Mold Problem

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  • Last Post 23 January 2011
Steve E posted this 07 July 2010

It might not be a mold problem it might be a me problem.  I have been casting Lyman 475 gr. 45/70 bullets and it seems I have a spot on the middle band that doesn't want to fill out. I am using straight wheel weight and have tried casting at 650, 750 and 800* to see if it will fill out but It still seems to be there, even after casting 40 to 50 bullets at each setting. Mold is clean, mix is clean. I am a newbie to casting as I only started in 1992. Thanks for any info.

 

Steve E...........

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Dollar Bill posted this 07 July 2010

Steve, I would have to say that the mold is not clean at that point. Sometimes, when I'm having problems like that, I wrap a piece of OOOO steel wool around a wooden dowel, chuck the dowel up in a cordless drill and spin it in the mold for a minute. That usually takes care of the problem. HTH.

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Steve E posted this 07 July 2010

I just happen to have some 0000 and a dowel that i was using to clean up a chamber so I can use that. It looked clean but I guess it might not be. I'll give it a try. Thanks.

 

Steve E.........

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RicinYakima posted this 07 July 2010

"Looking clean” usually isn't enough. Oils and greases in the pores of the metal may only be weeping out at high heat. Boiling water, an old toothbrush and a little soap will usually cure this if it isn't caused by a blocked vent line. Ric

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jppr26 posted this 08 July 2010

i have had the same problem, and as ricinyakma said boil it and scrub it with some dawn, works for me.

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Daryl S posted this 15 August 2010

Hot tap water, toothbrush and Ajax Cleanser does an incredibly good job of de-greasing about anything.

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.22-10-45 posted this 03 December 2010

Hello, Steve E. If mould is truly clean, try smoking cavities with wooden match, try casting with untouched smoked cavity & try after lightly brushing out with soft natural bristle brush. Be sure to brush out the vents before casting. If still balky, try a very thin strip of paper between blocks at that point...If band fills out, it is a venting problem & one or more vent lines need to be looked at. Best of luck!

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hunterspistol posted this 03 December 2010

     They are 100% right, the wrong contaminant in the mold and spots appear.  I've had the cleanest looking molds do that.  It can be a very light film or just a spot of something that splattered into one section of the mold.

     Ron

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Fg1 posted this 03 December 2010

Lighter fluid , acetone, denatured alcohol, rubbing alcohol and q tip scrub sometimes help too .

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Steel 13 posted this 09 December 2010

I cast the Lyman 457125 500gr. and have had difficulty getting middle of the bullet fill in initially as well. My problem was temp. Even though the mold was pretty hot, getting good nose fill and good base fill, the middle of the long fat bullet was not up to temp yet. The nose gets hot from preheat. The base gets hot from sprue. It just takes a bit more time to get the middle to fill. I had to take my mold to just the point that the outer edge of the base was frosting until I got good fill. alloy was 40 to 1.

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CB posted this 09 December 2010

Boil it in hot tap water. Disassemble the mold and boil the crap out of it. The hot temp will expand the pores in the metal slightly, make the oil more viscous and then it will float to the top. Remove the mold and let it dry and cool on a paper towel and reassemble when cool. Avoid putting in any soap or cleaners like TSP. If it is really cruddy, scrub out with a toothbrush and a cleanser like barkeepers friend, but be cautious as this is an abrasive cleaner.

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Trap4570 posted this 10 December 2010

Cleaning the mold with hot soap and water works well. I always baste the inside of the mold with cold blue. It helps to seal out oils during storage and it also gets the mold dropping good bullets quicker. Also I avoid commercial oils for storage because they have additives designed to penetrate and protect. I use olive oil stolen from the wife's cabinet. It works well for me at least.

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adrians posted this 23 January 2011

all of the above and also get a magnifying glass out and check your vent lines in that area,a blocked vent line can cause a small “air pocket ,so to speak ” and restrict flow of melt. it could be that simple . have a great evening .adrians :hunt::taz::riflebr:

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CB posted this 23 January 2011

I'll go with Steel 13 on this one. Stick the front bottom edge of the mould in the melt for about a 30 count and see if it fills out. The bullet will be frosted as hell for the first few casts but let the mould cool a bit and I think you'll be ok. Run the alloy at a temp that will give a nice even frost with WW.

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