toadfrog Posted August 1, 2013 Report Share Posted August 1, 2013 I haven't had time to really think this through so I'm throwing this out for pro's and con's . Lead melting , lead pots ect . have often been the topic of conversation . Once in a while somebody mentions pressureized lead injection . I have mulled this over a little but I'm so strapped for time I haven't been able to put theroy to fact . I was thinking might be possible to make an economical lead injection this way . Take a machined cylinder that will have an I.D. to match a piston . Create a manual arm that can move the piston up and down in the cylinder . The arm should be able to raise the piston completely out of the cylinder for lead loading . Create a slide bar gate valve and end cap that is screwed on to the cylinder for access and cleaning . This unit could possibly be heated by digitally controlled bands rather than an element . Also the slide bar would need a heating element . Once assembled pressure could be applied to the lead before opening the gate to the mold by the arm handle . I also realize that automated means could be applied if the lead can't pass the piston rings . Like I said this is just a nutty Idea if anybody wants to chime in here please feel free . Or just tell me to go jump in the lake . Quote Link to comment Share on other sites More sharing options...
Kasilofchrisn Posted August 1, 2013 Report Share Posted August 1, 2013 (edited) What are the goals of this project? Are you thinking this would lead to more complete pours in molds that do not like to fill out completly? Maybe a time saver via faster pours? Possibly this could be used to fill larger molds say ~3oz and above that would normally not allow use of a bottom pour pot? This would neccessitate a large resevoir as big jigs use a lot of lead. I make really big stuff so I know this well. Would Jamming the spout into the gate be enough to stop lead from spewing out around the mold and possibly burning onesself? I am not sure most of us have need for such a system but you never know. Price might also be an issue. Especially when you are potentialy talking some machinist work to the cylinder and bore. Edited August 1, 2013 by Kasilofchrisn Quote Link to comment Share on other sites More sharing options...
DaBehr Posted August 1, 2013 Report Share Posted August 1, 2013 It would make me REALLY nervous to have molten lead at 621+ degrees under pressure. You would need some significant safety shielding or it could be deadly. The reason why lead pouring works as well as it does is because lead is dense and it gravity feeds nicely. There are a number of large lead pour pots out there that allow for volume ...but rely on the gravity feed vs a pressure feed. Quote Link to comment Share on other sites More sharing options...
JSC Posted August 1, 2013 Report Share Posted August 1, 2013 TF --- U havin night mares again? Seriously all of the commerical lead pouring that I know of use the gravity flow of lead from a pot of sorts .. know of them being automated to the point of clipping the sprue and back into the pot (This is on some Egg sinker molds) Also one company (I think it was FLA Tackle) that poured the lead in a flat ribbon and "Punched out" split shot and the remainder of the ribbon went right back into the pot ... Do not know if any use a pressure system out side of gravity flow ... seems if it would have been practical some one would have done it (and maybe they have) ... Quote Link to comment Share on other sites More sharing options...
toadfrog Posted August 1, 2013 Author Report Share Posted August 1, 2013 YES it was another night mare jsc ! ARRRG got to lay off those knarly chilli dogs . LOL The goal was to make more complete pours on hard to pour molds . I just thought I'd bounce it off every body to see what they thought . So far I think I better look for a nice lake to jump into . I do understand the danger but I'm known for going full steam ahead till I'm dead . I also do big stuff but nothing that weighs over a pound and anything like that needs to be ladled anyway It's just easier for me . The only pressure system I know of uses an auger type system that pushes the molten lead through a die assembly and onto the product . Once the auger stops the lead pressure drops Almost immediately . Talking some real live expense with something like that. I've even considered that since a system like that is not gravity feed it would not have to be vertical but horizontal which has implecations in itself . Like loading a mold . The size and no of cavities that would be possible . All in all centrifugal casting still got it beat . Quote Link to comment Share on other sites More sharing options...
joelhains Posted August 1, 2013 Report Share Posted August 1, 2013 I think a larger opening in the bottom of the pot would be more effective than all the moving parts required for a pressurized system. I was thinking about this today as well. I was pouring some spinnerbaits and the 1/2 ounce heads wouldn't fill completely. I kept thinking "if only my pot had a larger opening so the lead would flow quicker". Quote Link to comment Share on other sites More sharing options...
mark poulson Posted August 2, 2013 Report Share Posted August 2, 2013 Isn't that what centrifugal molds are supposed to do? Quote Link to comment Share on other sites More sharing options...
cadman Posted August 2, 2013 Report Share Posted August 2, 2013 I think a larger opening in the bottom of the pot would be more effective than all the moving parts required for a pressurized system. I was thinking about this today as well. I was pouring some spinnerbaits and the 1/2 ounce heads wouldn't fill completely. I kept thinking "if only my pot had a larger opening so the lead would flow quicker". Joel, You have a valid point with making the lead flow faster. However there is at some point a trade-off. Reason being is the faster the lead flows or pours the better chance of getting air pockets which means you will get bad or incomplete pours again as trapped air will not allow lead to seep in. I have tried this (not to say I did it right or correctly), and that was my result. Maybe a faster flow with a bigger sprue opening. However a bigger sprue means you will have to saw it off and won't be able to use gate shears. There are soooo many variables. On bigger jigs this might work. On smaller jigs I found slow and steady with a tilted mold works 90% of the time. Then you have lead composition, humidity, reliefs in mold to let air escape and other things. I have shoved lead mold sprue holes up against pot nozzles and let gravity force the lead into the cavity but this was on mainly smaller jigs biggest being 1 oz. This is a very interesting topic to explore and I would like to hear everyone's input on how they do all of their finicky pours. Quote Link to comment Share on other sites More sharing options...
JSC Posted August 2, 2013 Report Share Posted August 2, 2013 "I have shoved lead mold sprue holes up against pot nozzles and let gravity force the lead into the cavity" (Cadman) I have found that is the best way on all the molds I have (Xcept some spinner/buzz bait molds where I have to ladel). TF Mention the "Auger" type reminds me that I have heard of lead being "Pumped" as well. Quote Link to comment Share on other sites More sharing options...
