Been a long time

[30calpal]

Since I have cast my own. The weather was COOL and my melt kept skimming over. I have an alum two hole mold. I never did get the rear hole to make a decent boolit. Front hole made on 10-12 from 6-7lbs of wheel weight and sinkers. Rest had to go back in the pot. Pot is new, Lyman. Had it set at 80% but my Harbor Freight infrared thermal temp gun registered only 450*. Does lead pour at 450*? Maybe the temp gun is off. Maybe the pot is not heating up where it should? Next time I'm going to put the mold on a hot plate. You guys tell me what I'm missing here,...what am I doing wrong ...or right. Thanks.

[Bret4207]

Lead melts at about 620F, tin melts at about 450F. If you temp gun is accurate I'd say you have a lot of tin in your alloy. I'm not sure exactly how the mechanics of an alloy work, that is how much tin it takes to lower leads melting point, but I do know some of the softer alloys need a hotter pot.

I'd turn the pot up and start casting. Remember that your control mould temp with your casting tempo, the more time you stand there with an empty mould in your mitt looking at fresh cast boolits the more the mould cools. Pot temp and mould temp are 2 different things. As long as the alloy is liquid enough to pour consistently you can, in theory, cast with it. In practice it usually takes some time under your belt to learn to cast well at lower temps.

[Bad Water Bill]

Part of the problem could be the mould still has some cutting oil from machining in it. Try putting the mould in a pot of soapy water and cooking it for about 15 minutes. Rinse the mould out with fresh water right from the tap and let completely dry.

There have been several posts here on the failure of those fancy heat testers when trying to check the temp of molten lead. Sometimes it's best to stay with the tried and proven things.

[Harry]

IR temp guns are not accurate when directed to shiny reflective materials such as the gleaming surface of melted lead. I would recommend a dial thermometer of the proper range.

[williamwaco]

pal . . .

Am I loosing my mind?

Didn't we do this question about a week ago?





IR thermometers are calibrated for non reflective surfaces, they will not measure any object with a shiny reflective surface.

I have always had trouble casting outdoors in cold weather. I am from Texas. Anything below about 45 degrees is cold to me.

If you can, take it into the garage. If not, try wrapping the pot with a couple of wraps of aluminum foil and make a cute little foil cap to set on top.

Do anything you can to keep the mold hot.

To get the mold hot, start casting as fast as you can without being careless. Dump the bullets as soon as the sprue turns frosty. Do not wast time looking at them. Refill the mold immediately and dump it again. Depending on the ambient temperature, the size of the mold and the size of the bullet, it can take from six or eight fillings and dumpings up to around 20.

You will know the mold is hot enough when it takes the sprue seven to eight seconds to solidify.




.

[Jim]

THIS (http://www.rotometals.com/product-p/lead_thermometer.htm) is the thermometer I use. It's accurate and does not fluctuate with the flames from fluxing.

I pre-heat the mold and run the alloy at 700. Doing that, I get excellent to perfect boolits on the first cast. The sprue hardens to cutting temp in less than 5 seconds.

There's a bunch or reasons one cavity won't fill. First thing that comes to mind is, the cavity might not be venting.

[1Shirt]

Never felt a need for a thermometer, still don't. I cast as hot as I can get the melt, and want the blts to drop at least a little frosty. Find I get more consistancy with that over shiny blts.
1Shirt!:coffee:

[30calpal]

No, Williamwaco, we didn't do this discussion a week age, ...least it wan't me with the question. Thanks to all for the suggestions. I cleaned the molds with acetone before using, but it was the FIRST use of the mold. Maybe nees some break in, or the vent lines need to be inspected under a mag glass.? I will use a high temp dial thermometer next time, and put the mold on a hot plate between pot refills...and pick a warmer day.

[mpmarty]

Good luck on a warmer day.