BigFoot Posted January 11, 2011 Report Share Posted January 11, 2011 Hey guys, I made a 2 part RTV mold of 1/2 ounce football jigs so I don't have to pour one at a time. Since I couldn't find a production mold for the football jig. Well it came out pretty good for someone who hasn't ever messed with the stuff. When I pour the lead its like the lead takes forever to harden and when i open the mold the head CRUMBLES. any tips or a place to get a production mold. if i wasted 30 bucks oh well. i tried and it gave me a lil bit of experience lol Quote Link to comment Share on other sites More sharing options...
psilvers Posted January 11, 2011 Report Share Posted January 11, 2011 I use RTV molds and they work OK. I think the problem is that your lead is too hot. Do you have a thermometer in the pot? Keep your lead at the lowest possible temperature that your particular alloy will permit. Do NOT let it get more than 650-700 degrees. I am pretty sure that is your problem. Pete Quote Link to comment Share on other sites More sharing options...
BigFoot Posted January 11, 2011 Author Report Share Posted January 11, 2011 I use RTV molds and they work OK. I think the problem is that your lead is too hot. Do you have a thermometer in the pot? Keep your lead at the lowest possible temperature that your particular alloy will permit. Do NOT let it get more than 650-700 degrees. I am pretty sure that is your problem. Pete you know pete now that you said something, I usually heat my lead in the pot at full blast and turn it down ... let it get to that low point as i pour in my aluminum mold. imma try that here in a minute and let ya know if it worked ... before i go do i need to heat the mold Quote Link to comment Share on other sites More sharing options...
BigFoot Posted January 12, 2011 Author Report Share Posted January 12, 2011 i let my lead melt at the lowest setting on the pot. it is a lee production pot . sigh ... any more suggestions from anyone or is this a lost cause? Quote Link to comment Share on other sites More sharing options...
psilvers Posted January 12, 2011 Report Share Posted January 12, 2011 Where did you get the RTV from? The stuff that I have used is from Miniature Molds and it doesn't give me any problems if I pour the lead between 650 and 700. Do you have a thermometer that you can put in the pot? One note - if you heat the lead on a 'High" setting and then then turn the heat down, it will still be WAYYYY too hot. If my lead is too hot ( as measured by a thermometer that reads up to 1000 degrees) I put in some bars and let them melt. That effectively lowers the temp. Pete Quote Link to comment Share on other sites More sharing options...
dlaery Posted January 12, 2011 Report Share Posted January 12, 2011 You need to wait longer before you open the mold. Silicone does not absorb heat like aluminum. I have several RTV molds and it takes 30 to 40 seconds before you can open and when the RTV molds get hot, it will take longer to open. For faster production you could make 2 more molds and then while one is waiting to open you could load another and pour, and so on. I will say this, I spin cast lead in vucanized silicone molds and I have used several different types of silicone and some take longer than others before you can de-mold. On spin casting I spin the mold, pour the lead and let spin fo 10 seconds, take out the mold and let set for 10 seconds, remove the top of the mold and let set for 10 more seconds before I demold. So thats 30 seconds before I can demold. Anything 1 oz or bigger needs to set longer, they are crumbly if I don't. Quote Link to comment Share on other sites More sharing options...
RSBreth Posted January 12, 2011 Report Share Posted January 12, 2011 I know this is leading you back the other direction from the RTV mold issues, but were you looking for a weedless or regular production jig mold in 1/2-ounce? There's a production mold for 1/2-ounce footballs here:http://www.luremaking.com/catalogue/catalogue-index/catalogue-items/football_jig_mold.htm If you were looking for a weedless version, wouldn't it be easier to just modify that mold for weedless pins? I don't know. Quote Link to comment Share on other sites More sharing options...
BigFoot Posted January 12, 2011 Author Report Share Posted January 12, 2011 Where did you get the RTV from? The stuff that I have used is from Miniature Molds and it doesn't give me any problems if I pour the lead between 650 and 700. Do you have a thermometer that you can put in the pot? One note - if you heat the lead on a 'High" setting and then then turn the heat down, it will still be WAYYYY too hot. If my lead is too hot ( as measured by a thermometer that reads up to 1000 degrees) I put in some bars and let them melt. That effectively lowers the temp. Pete I bought the alumilite stuff from hobby lobby .... i had a 40 percent off coupon lol so i thought why not. When I tried the second time I let it melt on the low setting Quote Link to comment Share on other sites More sharing options...
Peterjay Posted January 13, 2011 Report Share Posted January 13, 2011 Like Dave said, you're opening the mold too soon. Once the metal cools, it won't crumble. Give it 5 or 10 minutes and see if there's a difference. Work backwards from that and you should be able to figure out a demold time. There's a huge difference between a silicone mold and an aluminum mold as far as demold time goes. Also, a silicone mold will retain heat longer - you might want to let it cool down a bit after a few pours, otherwise, you'll be increasing your demold time even more. Quote Link to comment Share on other sites More sharing options...
BigFoot Posted January 13, 2011 Author Report Share Posted January 13, 2011 okie dokie ill try that ... im really ready to see if my cousins bro in law will cut a mold for me in his cnc if i drew it in cad for him since his machines can open cad drawings and cut lol ... Quote Link to comment Share on other sites More sharing options...
RSBreth Posted January 18, 2011 Report Share Posted January 18, 2011 1/2-OUNCE PRODUCTION MOLDS. I think maybe you didn't read this, or is it not what you were looking for? I know this is leading you back the other direction from the RTV mold issues, but were you looking for a weedless or regular production jig mold in 1/2-ounce? There's a production mold for 1/2-ounce footballs here:http://www.luremaking.com/catalogue/catalogue-index/catalogue-items/football_jig_mold.htm If you were looking for a weedless version, wouldn't it be easier to just modify that mold for weedless pins? I don't know. Quote Link to comment Share on other sites More sharing options...
BigFoot Posted January 23, 2011 Author Report Share Posted January 23, 2011 1/2-OUNCE PRODUCTION MOLDS. I think maybe you didn't read this, or is it not what you were looking for? It wasn't what I was looking for because of the weedless :-( I was all excited when I saw it and it was for non weedless i got sad Quote Link to comment Share on other sites More sharing options...
BigFoot Posted January 23, 2011 Author Report Share Posted January 23, 2011 (edited) AHHHH DOUBLE POST! Edited January 23, 2011 by BigFoot Quote Link to comment Share on other sites More sharing options...
