Fill out problems

[epj]

Been casting some 158 gr in a new Lee 6 cavity. Even though I am making a much larger sprue than I did with the 2 cavity mold, I am seeing a lot of the boolits come out with poorly filled bases. Many almost look like they are bevel base, though the mold is definately a flat base design. I'm wondering if my alloy needs more tin. Using smelted ww's that contain a small percentage of soft lead stick on ww's. I'm thinking that in the course of smelting that I have been inadvertantly removing some of the tin with the dross. Also, I just read the thread concerning zinc contamination. Never seen anything that looks like oatmeal on top of the melt, but there are certainly zinc ww's in the mix as well as steel. So far as I can tell, I'm gettting them all out of the alloy before they melt, but since I don't have a thermometer, I'm not really sure.

As a side note, the 6 cavity molds sure put out a lot of boolits. In some cases, I only got 4-5 good boolits per pour, but still managed to produce over 1000 in the course of a couple of hours. Years back, I had a Lyman or RCBS 4 cavity mold for 200 gr .45's. That puppy absolutly wore me out, and I was 30 years younger!

[docone31]

You can try more tin, but, I suspect you need to crank up the heat!!! If you are useing a bottom pour pot, put it flat out, fill the mold after preheating it, let the castings sit in it after cutting the sprues.
I like to set my Lee Molds in the pot untill the lead falls off the bottom, then when I start, I like to see my sprues take forever to freeze. From there, I let it cool enough to see the spure button flash grey and the center pull in.
After reading on the results of others, I am so glad I only have two bangers.

[Larry Gibson]

As mentioned; turn up the heat and preheat the mold. It appears you're using straight WWs so if that doesn't work add 1-2% tin.

Larry Gibson

[Calamity Jake]

As stated above, more heat with a little tin, and, Venting, Venting, check the venting, you need to get the air out.

Use a fine knife sharpening stone and put a VEEEEEERRRRRYYYYY small bevel on the cavity side of the mold at the top along its full length. Then lightly smoke the cavities with a butane lighter.

[epj]

I'm using two Lee 10# bottom pour pots. Thermostat never gets off max. The sprues are taking a few seconds to harden. Still, you may be right about the heat. In some cases, I'm getting some run over into the next hole before I can get the mold lined up to pour directly into the cavity . This usually results in a reject.

[j20owner]

Wow, about your heat settings. I never have to turn my Production Pot 4 up past 5 and if I cast too fast, it takes forever for the sprues to cool enough to get a clean cut on the base.

[jdgabbard]

I turn my Pro 4-20 over 5 and my heat is just way too high. I try to stay under 700. If your mold is still too cold doing that, then you just need to cast faster.

[Echo]

To condense, add a little tin (lino, solder, whatever, to get up to at least 2%). This means 50/50 lino/WW, or a quarter pound of lead-free solder per 10 pounds of WW. If this still leads to rounded bottoms (Hmmm...), then kick up the heat. Should not need to go over 700* with this alloy...

And cast fast to keep the mold hot. If it gets TOO hot, set it on a sopping wet (not damp - sopping!) towel for a few seconds to cool down. In my experience, if the sprue starts breaking when I knock it off, I am too hot and need to cool down.

[jdgabbard]

In my experience, if the sprue starts breaking when I knock it off, I am too hot and need to cool down.

Yeah, but I've been to that point and still had my boolits not completely fill out. One of these days when I decide to drop some cash I'm going to invest in something a bit nicer than the Lee stuff to see if it makes any difference. I have noticed though that the TL boolits tend not to fill out as nicely as the non-TL molds though.

[TAWILDCATT]

the lee molds are good molds just takes the right tecneac?.they need to run hot.
I take a new mold and stone the faces,then fine fill and break the corners all around.smoke the new mold as lee tells you.I have several makes are have used them and they all work if you know how.after over 60 yrs I do.

[mooman76]

If you are ladel pouring make sure you leave a good size puddle of lead over each cavity. That helps to increase the presure when the lead shrinks down.

[randyrat]

In other words... Run your mold hotter not your lead. It takes a lot of heat to heat a 6 banger up to to the right temp. Untill the heat is even and hot enough you'll have fill out problems.