pouring flutter jig with tire weight lead

[hivetool]

I am having trouble getting a complete pour on these thin jigs. have Lee melter set on 9 and preheat mold on top of melter, then more preheat by pouring both cavities, then trying a final pour in hot mold. I can get a pretty complete 2oz, but the 3oz never fills out. wut Im doin wrong?

[bigjim5589]

 Most incomplete pour problems are due to the mold not being hot enough or not staying hot enough between pours.   If you happen to have "ripples" in the lead of those that are not pouring completely, that's a good indicator that the lead is cooling faster than the cavity is filling.

That is not necessarily a problem with the flow rate either, as you can only get a limited amount through the cavity opening. The problem is that with the mold not hot enough, the heat in the lead is transferring into the mold, heating it up, but at the same time cooling the lead too rapidly.  If the mold is already plenty hot, you don't lose the temp in the lead at the same rate, so it flows into the cavity & fills it before it cools too much.

That mold should be very hot, like closer to the lead melting point hot and kept that temperature. 

Another possible issue that causes incomplete pours, is air cannot escape the cavity and is trapped by the lead. Air & lead cannot occupy the same space at the same time. In that case, vents added to the mold help eliminate the problem. I have that mold and have not had any problems with pouring it as far as air being trapped, but I also get the mold very hot. I also use wheel weight lead for a lot of pouring and even though it's considered a "hard" lead, it's neither hard nor soft when molten and is likely still 93 to 95% lead. Be sure you're melting down any wheel weights into ingots before attempting to use them to pour with. Don't put wheel weights into a bottom pour either if that's possible. I use a different pot, a small cast iron pot, to melt down any scrap lead, so I'm only adding ingot lead into my bottom pour.

Getting that mold a lot hotter should cure the problem.   I bought an inexpensive hot plate to use to preheat molds & keep them hot, and that's worked very well.  Since the exterior sides on many Do It molds are indented, I'll also sometimes pour on the outside to get the temp up. That's about surface area, and heating up a larger area at once. Do that several times and the mold should be plenty hot as long as you don't allow it cool down.

[anyfish]

I'll just add, if you don't already, consider smoking the mold or even better in some cases, get the casting release spray that Do It sells. 

[Apdriver]

Good info above but what pot are you using to/how are you pouring this mold?

[ctom]

Welcome to the Do-It forums hivetool!

When I've encountered incomplete filling issues I have had good luck giving both sides of the mold a shot of drop out, then cranking the heat to max. If you are not hand pouring those 2-3 ounce jigs you need to be. Bottom pour pots are terribly inefficient at filling big cavities completely.

[hivetool]

thanks for the replies. so, get it all hotter, yes? my LEE melter pot is a bottom pour and the lead comes out in a piddly little stream. filling mold with a ladle would be faster and result in better fill? I have opened up the fill hole with a file but didnt help have not had any problems pouring 8oz sinkers and jigs

[hivetool]

was wondering about adding some tin to get better flow?

[bigjim5589]

Adding tin cannot change the volume coming from the bottom pour nor will it change the mold temp. If you're not getting a good flow, then perhaps there's something clogging it.

I have both a 20 lb Lee bottom pour pot and the Palmer Hot Pot II electric ladle. I generally don't pour anything heavier than 3 oz with the bottom pour and prefer the Hot Pot for most pouring anyway.  However, I use my bottom pour plenty, and clean it about once a year. There's usually some rust/oxidized metal that needs to be cleaned out, as it can break loose and clog up the spout.   Be sure that you're keeping the pot as full as possible when not using it, as that aids in limiting oxidation of the inner wall. It will take longer to melt, but your pot will stay cleaner for a longer time frame.

When I do clean mine, I run a drill bit up into the spout, by hand and that cleans it quite well. I don't recall the drill bit size that I use, but it's the same diameter as the inside of the spout. I don't try to open it up larger since that will likely result in it dripping too much.  Mine's well over 30 years old, and still works fine.

[Apdriver]

thanks for the replies. so, get it all hotter, yes? my LEE melter pot is a bottom pour and the lead comes out in a piddly little stream. filling mold with a ladle would be faster and result in better fill? I have opened up the fill hole with a file but didnt help have not had any problems pouring 8oz sinkers and jigs

Exactly what I was thinking. The Lee bottom pours are infamous for plugging and stopping up with contaminants and rust. Take a Spinnerbait form or wire and probe that hole while the lead is coming out. Catch the lead in something, wear gloves, and foremost be careful. I’m pretty sure your lead is cooling before the cavity I full creating incomplete pours. I’ve seen this before.