TBait Posted October 20, 2004 Report Share Posted October 20, 2004 Is it possible to overheat lead, for a pouring or casting situation? I use map gas instead of propane and the lead seems to set up quicker than when I used to use propane. Is this just my imagination? I am using different types of molds. From wood to metal to putty. I know.....dumb question. Quote Link to comment Share on other sites More sharing options...
TBait Posted October 20, 2004 Author Report Share Posted October 20, 2004 I am using bulk shotgun shell shot, to melt down for my lead. Only because it was free. Could this lead shot be the problem? Quote Link to comment Share on other sites More sharing options...
jigmaster Posted October 20, 2004 Report Share Posted October 20, 2004 Not sure there would be any difference from heat sources. I do know that you can overheat lead.....when it starts to take on a reddish hue......then it is too hot. That is also when it starts to get dangerous to inhale, as it gives off toxins in the fumes. I typically pour at about 750 deg. seems to be the best temp range. The shot may be contributing to the variation in some way...my guess is that it is indeed part of the equation. Quote Link to comment Share on other sites More sharing options...
Glaucus Posted October 20, 2004 Report Share Posted October 20, 2004 It is possible that overheating will change the composition of some lead alloys. Tin, if present, will oxidize, thereby changing the alloy. A tin-lead alloy melts/solidifies at a lower temperature than pure lead. Here is a phase diagram for lead tin, it shows the melting temperatures http://www2.umist.ac.uk/material/research/intmic/phase/pbsndiag.htm Adding flux to lead alloys will reverse tin oxidation. I've used shot before and had no problems with it, if I got it for free I'd definitely use it. Some shot contains arsenic, which increases hardness. This site has more info about lead http://www.lasc.us/myweb/CastBulletNotes.htm Quote Link to comment Share on other sites More sharing options...
Richoc Posted October 21, 2004 Report Share Posted October 21, 2004 Mapp also leaves a gas in to the lead mixture. It burns hotter because it is half acitilene gas. Just exposing the lead to Mapp will cause it to become a harder lead mixture. Best not to use Mapp for the lead, for casting. Setting a cast iron pipe, the only why to go. Quote Link to comment Share on other sites More sharing options...
TBait Posted October 21, 2004 Author Report Share Posted October 21, 2004 I will switch back to propane. .. Quote Link to comment Share on other sites More sharing options...
