Six cavity mold technique

[wallenba]

I just started using this website, so forgive me if this subject has been covered. I've been using Lee two cavity molds for a while with no problems. Since buying my six cavity molds I just can't seem to get them up to temp and keep it there. I thought about using a hot plate, but don't really want it laying around while I'm working. I thought if I just kept pouring sooner or later it would come around and give good boolits. Nope. Pot is set at seven and a half. Is the mold is too big to get a good heat sink from my pot, or is the aluminum just shedding heat too efficiently?

[ghh3rd]

I wonder if your pot is runnnig cool, although, if the boolits are filling out correctly, it seems like the mold should heat up accordingly. Are you taking long between casts? Is there a strong breeze (perhaps a fan) blowing on the mold?

Perhaps you can lay the mold accross the top of the pot in between casts to keep it warm.

Randy

[ept000]

If you cast faster your mold will stay hotter.

[wallenba]

I wonder if your pot is runnnig cool, although, if the boolits are filling out correctly, it seems like the mold should heat up accordingly. Are you taking long between casts? Is there a strong breeze (perhaps a fan) blowing on the mold?

Perhaps you can lay the mold accross the top of the pot in between casts to keep it warm.

Randy

Yeah I use a small box fan for cross ventilation, but I' m not letting the mold dwell in the breeze. I could speed up a little to see if thats the problem, but I really don't think so. It's been cool up here in Michigan for spring, and I cast in my garage. I really did not consider that before because it was not a problem with the other molds. I'll try on a warmer day.

[truckmsl]

I'm using a Lee 4-20 pot and 6-cavity aluminum molds with no troubles. I lay the mold over the pot when I first turn it on, let the pot get up to around 850 F, and start casting with good size puddles on the sprue plate. Depending on which mold it is I might turn down the heat after a bit, but I always place the mold back on top of the pot when fiddling with boolits or whatever. I had to replace my thermostat once, but it'll run 900 F now if I let it. I cast fast enough that I need to cool the mold down on a wet sponge occasionally.

[Bret4207]

The 2 ways I know of to affect mould temp is alloy heat and casting rhythm. You can up the heat and up your tempo a bit till you hit a happy medium.

[Gunslinger]

I find the perfect solution to be dipping the sprue plate on a wet cloth allowing it to cool rapidly! There's a thread on it somewhere, speedcasting bruce something. It works great... boolits pile up very fast with a single 6-cav...

[mpmarty]

Other than my 45/70s and 311413s all I use are six cavity Lee molds. I've got two 452s and two 401s for my 45acp and 10MM pistols. Shooting both IPSC and IDPA it's sometimes hard to keep up with demand:bigsmyl2:
I use a shallow 12" round pan with a folded towel and water and with pot temp at 700 to 725* after a few casts I rest the mold on the wet towel for a few seconds before cutting the sprue and dropping it into the pot and then dropping the boolits. By doing this I can cast as fast as I can pour, swing the sprue plate and drop boolits and not have more than very minor frosting.

[Springfield]

First off, forget the "7 and a half" , and get a real thermometer. Second, how long do you wait after pouring until you cut the sprue? If it is much over 12 seconds then it is probably too long.

[Fish_N_Russ]

dunk your mold in the pot and keep it there for count of 10, should be plenty hot then....
also make sure your lead flow is not blocked ie clean out the spout, you want a full fast stream coming out. Then you can just pour in one swipe as the molds fill, cut the sprue, tap the mold on a wood block, open up and drop boolits (at least thats what my rythym is). good luck

[runfiverun]

my first lee 20 lb pot hit exactly 620 on full bore i had to adjust the contact points in it.

[garandsrus]

I think that the key to using any molds with more than two cavities is to pre-heat them. This allows the sprue to cut easily and gives good boolits within just a few casts. An easy cutting sprue saves a lot of abuse to the mold.

I use a lot of 6 cavity Lee molds and unless I am casting boolits over 300 or so grains, no cooling of the mold has ever been necessary. With most molds you can cast as fast as you want to without overheating. I keep my alloy between 650 and 700 degrees F.

John

[Goatlips]

Wallenba, I cast the six holer and it seems to stay hot for me. Touching the sprue to a wet rag and keeping up a good rythm seems to work. I cast in Michigan too, mostly Cowboy. :Fire: I have a site here that might help and likely could do no harm. Needs updating:

http://goatlipstips.cas-town.com/casting.html

Goatlips

[wallenba]

To all, thanks. I got some good tips here. Strangest thing though. When I ordered the molds from Midway they had no handles in stock, so I welded up a working set from scrap stock I had in the shop. Yesterday two handles arrived that I ordered direct from Lee Precision, so I put them on a mold and began casting good bullets within five throws! I can't figure out any thermodynamic reason why this is, but nothing else is different. The 1 x 1/8" flat mild steel stock I used might have been working like the cooling fins on a motorcycle engine, thats the best I can come up with. Thanks again, Wallenba.

[wallenba]

Wallenba, I cast the six holer and it seems to stay hot for me. Touching the sprue to a wet rag and keeping up a good rythm seems to work. I cast in Michigan too, mostly Cowboy. :Fire: I have a site here that might help and likely could do no harm. Needs updating:

http://goatlipstips.cas-town.com/casting.html

Goatlips
I'm in Garden City, you?

[UncleClark]

I have had pretty good luck with the Lee 6 cavity by preheating by sticking the nose of the mold into the melt until the lead doesn't freeze up on it any more, then wait a minute or two and then start casting. I never cool the mould - if I see its getting too hot then I just keep the mould open for 15 seconds or so to let it dissipate some heat. Those moulds like to run pretty hot.

[KYCaster]

To all, thanks. I got some good tips here. Strangest thing though. When I ordered the molds from Midway they had no handles in stock, so I welded up a working set from scrap stock I had in the shop. Yesterday two handles arrived that I ordered direct from Lee Precision, so I put them on a mold and began casting good bullets within five throws! I can't figure out any thermodynamic reason why this is, but nothing else is different. The 1 x 1/8" flat mild steel stock I used might have been working like the cooling fins on a motorcycle engine, thats the best I can come up with. Thanks again, Wallenba.


Sometimes they just need a break-in run. You can't get a good boolit out of some new molds no matter what you try. Set it aside and try it again tomorrow and beautiful boolits will fall out of it like rain.

Don't sweat it...it's just the Galena Gods trying your mettle.

Jerry

[badgeredd]

To all, thanks. I got some good tips here. Strangest thing though. When I ordered the molds from Midway they had no handles in stock, so I welded up a working set from scrap stock I had in the shop. Yesterday two handles arrived that I ordered direct from Lee Precision, so I put them on a mold and began casting good bullets within five throws! I can't figure out any thermodynamic reason why this is, but nothing else is different. The 1 x 1/8" flat mild steel stock I used might have been working like the cooling fins on a motorcycle engine, thats the best I can come up with. Thanks again, Wallenba.

Hi from Three Rivers.

I believe you have the thing figured out. I'd agree that your "temporary" handles likely were acting as a heat sink. FWIW, I much prefer to have my molds pre-heated on a hot plate. I have it setting away from my casting area and as soon as the mold is up to heat, I turn off the hot plate and start casting like a fool. Usually the second fill are good boolits.

Just a thought.

Edd