What is best technique to keep molds warm when casting?

[terrydull]

What has been your experience to be the best technique to keep the molds warm during the casting process?

Minnie's all turn out good until the mold starts to cool down ...

then, I put it back in the oven to heat it back up. There's got to be a better way :confused:

Thanks, in advance, for your suggestions.

Terry

[Rob FreemanWBR]

Casting with molten lead is the best way.

Using an "oven"?????

I typically reject the first 10 - 12 casts as the mold is warming up, when I start to cast a batch of rounds.

By the 12th pour, the mold should be warm/hot enough based on the quality of your cast bullets - results may vary.

Continuous casting should keep your mold at a relatively steady temp.

[Maillemaker]

What I read, and fully agree with, that like almost everything with firearms, consistency is key. So that means don't stop and admire your work while you are casting, and don't change what you are doing while you are casting.

My biggest problem while casting is not the mold going cold, its the mold getting too hot. You end up waiting for he bullet/sprue to solidify.

So generally what I do is cast with two molds. I fill one mold and then set it aside to solidify, then I pick up another mold and fill it and set it aside to solidify. When the second mold is down, I pick up the first mold and it is ready to pop open and drop the bullets into a 5-gallon bucket of water with a towel clamped to the mouth so that only a couple of inches of water are visible in the basin formed by the towel. Then I fill the mold and set it down, and pick up the second mold and break it open into the bucket, and so on.

In this way the molds stay hot but do not overheat.

If I am not needing two different kinds of bullets then I only do one, but I have to wait a fixed amount of time before I can strike the sprue. I flip my sprue striking stick 5 times and then it is time to break open the mold.

Steve

[terrydull]

Using an "oven"?????



Yes, I pre-heat my molds in the oven ... that way I don't have to pitch the first "batch" ... but when they cool ... the minnie's skirt becomes defective ...

I guess I need to pick up the pace when casting ...

[jonk]

Just as my melt gets molten, I put the mold on a stove burner and set my dipping ladle in the melt. stove burner is on a medium low flame (gas). I wait about 3 minutes, then take the now hot ladle out of the melt, flux, set it back in, then go get the hot mold. Perfect fill otu from the start, or at least as perfect as anyone gets; still might get 1-2 rejects per batch.

If I keep the pot on high the mold certainly doesn't cool down any. It gets hotter still. With pure lead, getting 'too hot' isn't a problem either. Pure lead hardens fast and the sprue doesn't tear when cut. I just keep it on full blast.

If you are having the mold cool off too much to get good fill out you need a new element, thermostat, or both; or if using a coleman stove or something, simply more heat.

[RaiderANV]

Terry......sounds lkke your lead my not be hot enough? I cast between 850-925. I have two pots strung one above the other. then handles are connected so when I open the bottom pot to pour the top one opens as well resuppling the bottom pot. I onky an lead to the top pot. This keeps my lead temp from dropping in bottom pot and I can cast a thousand minies without stopping if I don't get wore out first 😆

I also place my mold on top of the lead pot while it heats up. I might toss out the first two or three rounds. The two pots strung together work great when you cast fast and especially when cast Maynard rounds in a six cavity mold. Pot can run empty fast.

[terrydull]

Terry......sounds like your lead my not be hot enough? I cast between 850-925.

My lead pot only has Low Medium and High ... do they sell thermometers for this process? Or should I just keep it on High?

Thanks,
Terry

[Harley1247]

My lead pot only has Low Medium and High ... do they sell thermometers for this process? Or should I just keep it on High?

Thanks,
Terry

Your best bet is to use a thermometer. You can constantly watch the temp. and there is no guessing I used one for years. 750 degrees for lead and around 700 degrees for alloys. Midway, Cabela's and Lyman. Cost is around $60.00.

Pa. 1st Calvary, Company B
Art Forgione 01247

[Greg Ogdan 110th OVI]

If using an aluminum mold, cast like what Rob freeman said using the temps of Harley. You should be able to run about 2 1/2 bullets per minute. If using a 20# Lee pot temp should stab y between 750 and 800. No need to be hotter. For hard lead temp between 700 and 750. to recharge, add a 1# ingot every 15th bullet or so and temp will stay good.

Greg

[Maillemaker]

I also set my molds on top of the pot while warming up. But I also keep a blowtorch on my bench and I blast the mold with that for a couple of minutes prior to casting. That way I have virtually no throw-outs.

I love the idea of the double-pot setup! Very cool! Or hot! :)

Steve

[Robt. Propst]

I have found that starting using a full Rapine pot, balancing the mold on top of the ladle while the lead heats warms the mold quite well. A block of wood secures the handles outside and off the pot. First 2 or 3 bullets may be throwaways, but not many more. Same technique keeps the mold heated when taking a break.

[John Bly]

I've never had that problem. Get your lead hot enough to start with - somewhere around 800 deg F, preheat your mold and start casting. When the bullets look good, throw 5 more back into the pot and then start keeping them. If you keep up a good pace with your casting your mold will never cool down, in fact you may need to adjust your pace to keep from overheating the mold. You should easily be able to do 100 bullets an hour from a single cavity mold. Casting with a lead thermometer can help but it is really not needed once you get some experience. All molds have unique peculiarities that require you to learn just what they need for the best results. Best of luck to you.

[Mike McDaniel]

My experience: If you're using an aluminium mould, toss it. I've never found a way to keep one hot enough to make good bullets. Run the lead hot. Pre-heat the mould over the pot. Toss the first 8-12 bullets. Then cast as quickly as possible, especially with Minies. Don't bother to inspect the bullets, keep the pour going. Don't pour he lead directly into the cavity, pour it onto the sprue cutter and let it pour into the mould from there. Rock the mould gently as the lead hardens.

Minies are a PITA to mould. Round balls of .50 and less are MUCH easier.

[R. McAuley 3014V]

For the past 30 years, I've done all my bullet casting on a Coleman 2-burner stove, and typically lite both burners, using the left burner to heat up my bullet mould while using the right burner for a 10-lb lead pot. I rarely have any rejects, and once I begin casting from the pot, I simply turn off the left burner. I have at other times, spread open the mould placing it face in against the pot to heat up the mould, but have found using the spare (left) burner works best. Although I have a thermometer to check the lead temperature, I generally rely on the color to determine the ideal casting temperature -- usually when the surface turns to a yellowish-bronze color-- it's around 900 degrees. If the color begins to turn more bluish, I know its getting hotter, and turn the flame back to cool the molten lead so as to maintain a constant bronze color. On average, I cast between 150 to 200 bullets an hour depending on bullet weight, and often cast 300 to 500 bullets per casting session.

[Maillemaker]

My experience: If you're using an aluminium mould, toss it. I've never found a way to keep one hot enough to make good bullets.

Man, do you guys read a book or something after you do your pour? :)

The only thing that slows me down when casting is waiting for the darn sprue to solidify after the pour. As soon as that sucker frosts over I'm cracking it open and dumping the bullet. After the mold heats up you end up waiting longer and longer for the sprue to harden before you can dump.

I have no problem with aluminum molds. I've got a Lyman 575213OS that's aluminum, and I've got a Moose Molds that is aluminum. I also have Lee molds that are aluminum. None of them give me temperature problems.

The biggest problem with Lee Minie Ball molds is that they make the core pin and the blocks out of aluminum, and so they gall. But their simple book molds, like I use for round ball, are just fine. I also find it helpful to finely polish the top surface of the blocks and the bottom of the sprue plate to minimize galling between the steel sprue plate and the aluminum blocks. Moose Juice is also very good to minimize the friction there.

They say that the purpose of smoking molds is not so much as a mold release agent but as a thermal transfer barrier to the mold. If you are having heat loss problems you could try smoking your mold cavities.

I do agree, though, that steel molds are much more durable, provided you don't let them rust.

Steve

[Mike McDaniel]

I dump the bullet as soon as the sprue hardens, but have never seen a set of aluminium moulds that delivered anything but wrinkled bullets. My experience has been that they just can't retain enough heat to make a good bullet - not a big one, anyway.

[Timmeu]

I have 2 pots on the bench at all times. I use one and get the other up to speed and then trade back and forth. One is 20 pounder. When I get to the end of the two I size bullets while I am waiting. This keeps everything moving for me and getting my new rounds stored safely before I do something dumb an mess up the new lovelys.

[terrydull]

Thanks guys ... did a bunch last evening ... keeping the pot on the highest setting ... worked well ... round balls turned out great.

I appreciate the feedback.

Terry

[Tom Magno, 9269V]

I dump the bullet as soon as the sprue hardens, but have never seen a set of aluminium moulds that delivered anything but wrinkled bullets. My experience has been that they just can't retain enough heat to make a good bullet - not a big one, anyway.

Mike, I have two 6-gang moulds in Aluminum - a .54 Wilkinson and a .515 Maynard. Never have a problem with them at all, except the alignment pins need to be reset every once in a while. They stay plenty hot enough with 6 bullets in them at a time. I preheat on my stove, then go to work. Smooth bullets in all cavities, and usually mould 100-200 at a time from each and only stop to refill my lead pot and wait for it to come back up to temp.