CNC Molds N Stuff Posted December 12, 2016 Report Share Posted December 12, 2016 For those of you guys using teflon pins in lead casting molds: What is your casting life? 100, 1,000, 10,000, or more? If you have guesstimated the life what do you think are the things that kill them? 1 Quote Link to comment Share on other sites More sharing options...
Saugerman Posted December 12, 2016 Report Share Posted December 12, 2016 Bob, I have been using mine for several years. I know that they have been used 1000's of times. They are well worth the cost. Just my 2 cents. 1 Quote Link to comment Share on other sites More sharing options...
dlaery Posted December 12, 2016 Report Share Posted December 12, 2016 I don't think they wear out from the heat, but I could be wrong. In a silicone mold they don't get very hot but in an aluminum mold they would probably get a lot hotter. I have some that have poured 200,00+jigs with approximately 200 teflon pins and I don't see any breakdown of the teflon. I use a mic to check the diameter on the ends where they would be in the lead. what makes them wear out is they are pulled out with needle nose pliers and grabbed by the end instead of grabbing them in the middle. when grabbed on the end and using too much pressure with the pliers they get distorted, oblong, and then can't get the weed guard in the hole. 2 Quote Link to comment Share on other sites More sharing options...
jcool3 Posted December 13, 2016 Report Share Posted December 13, 2016 i had 3/16 teflon rods which warped badly. they were 3 inches long in the middle of a 5 oz inchiku jig. Teflon will get very soft, sitting in molten lead. 1 Quote Link to comment Share on other sites More sharing options...
cadman Posted December 13, 2016 Report Share Posted December 13, 2016 I was the one who started the craze here, learning about it from George Reeves. I've had teflon pins going on 6 years and they are still good. The only thing that happens to them is that they get bent a little bit (which you can bend them back) or I lose a few now and then. I easily pour 6-10 K jigs with the pins per year. I also use mine for painting as well. I wouldn't do this any other way. 1 Quote Link to comment Share on other sites More sharing options...
CNC Molds N Stuff Posted December 13, 2016 Author Report Share Posted December 13, 2016 (edited) I'm working on a project with a 1/4" diameter core. The original core pin was made from 303 stainless. It worked ok, but even very hot there were some constriction areas where voids often appeared. I switched to a 1/4" teflon core pin, and the voids are all but eliminated. There are some little things, but the difference in results is huge. Even with a cold mold. If the biggest problem with the teflon pin is mechanical damaged from removal my next step is to try to make it stronger. I already installed a collet closer (a 3 jaw or 4 jaw chuck would crush the rod) on my small lathe so I could turn the nose of the core round, and drill a hole in the tip for a mating wire core. Now my thought is to turn it around, put it back in the lathe, and drill and tap it for a screw that will reinforce it and provide a stronger point to use for pulling it out of the cast item. I wanted something that works, but I also want something that lasts. Thank you very much guys. P.S. A second benefit for the collet closer is that it makes radiusing the ends of mold alignment pins much faster than the 3 jaw I was using before. Edited December 13, 2016 by Bob La Londe Quote Link to comment Share on other sites More sharing options...
CNC Molds N Stuff Posted December 13, 2016 Author Report Share Posted December 13, 2016 The screw will also allow for a place to put the positioning cross pin shown in the picture. Yes, those are pliers marks all over the pins. Quote Link to comment Share on other sites More sharing options...
Salty's Posted December 21, 2016 Report Share Posted December 21, 2016 Billions and Billions served..... They don't go bad. I'm going on 10 years. Billions. Quote Link to comment Share on other sites More sharing options...
Skimpy Posted December 21, 2016 Report Share Posted December 21, 2016 I have no idea how many times ive used mine, but its been a few years Quote Link to comment Share on other sites More sharing options...
CNC Molds N Stuff Posted February 1, 2017 Author Report Share Posted February 1, 2017 2 Quote Link to comment Share on other sites More sharing options...
