tigerfire Posted April 23, 2013 Report Share Posted April 23, 2013 I looked around and searched, but couldn't find the answer. If I have a lead weight, can I make a two piece pop mold, then use the pop mold to pour lead into? Good idea, bad idea? Would I need some kind of special release agent? Is there a better way to make my mold? Quote Link to comment Share on other sites More sharing options...
CNC Molds N Stuff Posted April 23, 2013 Report Share Posted April 23, 2013 (edited) I would be hesitant to use POP for that, but silicone molds are used for lead with an expected limited life expectancy. There are even some videos on Youtube of guys pouring lead into silicone molds. There are some high heat silicones, out there for mold making, but some of these guys are claiming to get upwards of a hundred pours out of regular silicone caulk mixed with some kind thinner to get the consistency of pancake batter before making the mold. Been a while since I watched this video, but I think he said the mold shrinks a little bit. The best material for a lead mold is probably aluminum, but a custom mold is quite expensive. On the other hand, the mass produced aluminum jig molds are pretty darn cheap. Edited April 23, 2013 by Bob La Londe Quote Link to comment Share on other sites More sharing options...
andy1976 Posted April 24, 2013 Report Share Posted April 24, 2013 Talked,to a company that makes molds with plaster of Paris for hot glass. They said you have to mix silica sand into the plaster to make it heat resistant. You also need to make sure the mold,is completely dry. Post a pic of what you are looking to copy. A mold may be available. Bondo works really good. Got a lt of pours out of one Bondo mold. Quote Link to comment Share on other sites More sharing options...
RayburnGuy Posted April 24, 2013 Report Share Posted April 24, 2013 I would be hesitant to use POP for that, but silicone molds are used for lead with an expected limited life expectancy. There are even some videos on Youtube of guys pouring lead into silicone molds. There are some high heat silicones, out there for mold making, but some of these guys are claiming to get upwards of a hundred pours out of regular silicone caulk mixed with some kind thinner to get the consistency of pancake batter before making the mold. Been a while since I watched this video, but I think he said the mold shrinks a little bit. The best material for a lead mold is probably aluminum, but a custom mold is quite expensive. On the other hand, the mass produced aluminum jig molds are pretty darn cheap. Barefooted........cut off jeans..........no shirt..........This guy will never be the poster child for the safe handling of molten metal. Ben Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted April 24, 2013 Report Share Posted April 24, 2013 I agree with Andy, bondo would be my choice. But still the mold would have a limited life span. If you want to pour more than half a dozen at a time, then it would be best to make several molds, as the bondo tends to soften under the heat of lead pouring. Dave Quote Link to comment Share on other sites More sharing options...
tigerfire Posted April 24, 2013 Author Report Share Posted April 24, 2013 Cool video. I only need to make about 5 of these weights. So, I'm not too concerned about the life span. It sounds like bondo may be the way to go. Do the bondo molds get sealed like a pop mold? Thanks for the info everyone! Quote Link to comment Share on other sites More sharing options...
mark poulson Posted April 24, 2013 Report Share Posted April 24, 2013 Barefooted........cut off jeans..........no shirt..........This guy will never be the poster child for the safe handling of molten metal. Ben Amen!!! Kind of like roofers working hot tar with no shirt. Quote Link to comment Share on other sites More sharing options...
mark poulson Posted April 24, 2013 Report Share Posted April 24, 2013 I would be hesitant to use POP for that, but silicone molds are used for lead with an expected limited life expectancy. There are even some videos on Youtube of guys pouring lead into silicone molds. There are some high heat silicones, out there for mold making, but some of these guys are claiming to get upwards of a hundred pours out of regular silicone caulk mixed with some kind thinner to get the consistency of pancake batter before making the mold. Been a while since I watched this video, but I think he said the mold shrinks a little bit. The best material for a lead mold is probably aluminum, but a custom mold is quite expensive. On the other hand, the mass produced aluminum jig molds are pretty darn cheap. Bob, Do you know what kind of solvent/thinner they were using for the silicone? Quote Link to comment Share on other sites More sharing options...
andy1976 Posted April 25, 2013 Report Share Posted April 25, 2013 Cool video. I only need to make about 5 of these weights. So, I'm not too concerned about the life span. It sounds like bondo may be the way to go. Do the bondo molds get sealed like a pop mold? Thanks for the info everyone! No need to seal the bondo mold. Quote Link to comment Share on other sites More sharing options...
CNC Molds N Stuff Posted April 25, 2013 Report Share Posted April 25, 2013 Bob, Do you know what kind of solvent/thinner they were using for the silicone? I do not, but I thought he mentioned it in his comments on YouTube, Might be worth clicking the Watch on YouTube button. Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted April 25, 2013 Report Share Posted April 25, 2013 Like Andy, I didn't seal mine - no problems. Dave Quote Link to comment Share on other sites More sharing options...
Mr.Nsmith Posted May 16, 2013 Report Share Posted May 16, 2013 When you're talking about Bondo, a car body fixer (correct?), what is the product that you actual use (the name)? Quote Link to comment Share on other sites More sharing options...
CNC Molds N Stuff Posted May 16, 2013 Report Share Posted May 16, 2013 When you're talking about Bondo, a car body fixer (correct?), what is the product that you actual use (the name)? Bondo. http://www.tools2parts.com/Bondo-265-p/4619-4023.htm?gclid=CNabvpTvmbcCFWRyQgod6V8A1Q&click=1006 Quote Link to comment Share on other sites More sharing options...
Mr.Nsmith Posted May 16, 2013 Report Share Posted May 16, 2013 Thanks Quote Link to comment Share on other sites More sharing options...
Mr.Nsmith Posted May 16, 2013 Report Share Posted May 16, 2013 So you can use bondo to make a 2 part mold much like P.O.P. or silicone molds, correct? Quote Link to comment Share on other sites More sharing options...
CNC Molds N Stuff Posted May 16, 2013 Report Share Posted May 16, 2013 (edited) This guy thinks so. http://yumabassman.com/forums-new/index.php?topic=3194.0 I doubt it would work well for plastic, but with a mold release it looks like it works for lead. Edited May 16, 2013 by Bob La Londe Quote Link to comment Share on other sites More sharing options...
andy1976 Posted May 17, 2013 Report Share Posted May 17, 2013 I've seen some pretty decent plastics poured out of bondo molds. I used to thin mine some with bondo fiberglass resin. The bondo is pretty thick to pour and level. Quote Link to comment Share on other sites More sharing options...
yoda Posted May 17, 2013 Report Share Posted May 17, 2013 I used Bondo fiberglass resin the used for boats for soft plastics worked great and easily worked with sandpaper and dremmel. Quote Link to comment Share on other sites More sharing options...
