I'm doing something wrong...

[coopersdad]

I read of zen-like casting sessions, getting in "the zone" and pouring huge amounts of shiny perfect bullets varying .5 grain or less. My sessions are stress-filled and frustrating where I spend hours producing a bunch of unusable junk.

I am ladle-pouring 480 gr. Martini-Henry bullets, CBE brass mould, Lee 4-20 pot, RCBS ladle, 20:1 alloy from Rotometals. Thermometer in the melt always, first session was 730 and second was 800 degrees, tried to only cast when it was within 10 degrees of those. Mould and ladle pre-heated on a hot plate. Mould washed with dishwashing soap/hot water, then dried and degreased with acetone. Sprue plate very lightly lubed with bullplate.

Once the melt is to temperature, I'll put some sawdust in, let it burn, then stir with a wooden stick, and skim.

I cannot get into any consistent rhythm, since I have to stop and skim large amounts of gray powdery debris every three or so pours, sometimes trying some wax, or it gets into the ladle and into the boolits. I try to push it aside and dunk the ladle deep, doesn't seem to matter. I put the ladle and mould back on the hotplate during this to keep them warm, but surely the mould and ladle are cooling. Cast about 125 between the two sessions, no keepers.

I get debris inclusions and ugly rough bullets, contributing, with the temp variations, to large weight spreads, 4 - 5 grains spread pretty evenly, not a bell-shaped curve at all. The bases are usually nice and sharp.

I attached some photos of the melt debris after about three pours, and some typical boolits. I'd love some critique and suggestions!! Thanks!


I can't figure out how to make this right side up...
270503

270504

[44Blam]

I find that larger boolits are actually harder to get good cast boolits out of. I just did a session with a 350 grain 45 caliber mold and it took a little while to get them perfect.

One thing I found was that you have to pour it faster. I use a bottom pour and I found that I set it to where it starts to drip and then back it off just enough to stop it dripping. This makes it come out as fast as possible. Then I pour straight into the hole without touching the sprue plate and I end up getting good boolits. I do not have this issue with smaller boolits. I also tend to cast just under 700 degrees but I also use an alloy with more sn/sb.

Also, 4 grain difference is pretty big - if you look at the bases of the lighter ones, is there a little hole? Sometimes you can get a bubble in there. I throw anything that has even the smallest hole because I know there is a bubble and have no idea how big it is.

The pic of your boolits looks like you have good fill out and not too many wrinkles - just looks like maybe some of the carbon from the saw dust... To me, that's fine. I look for good fillout, no wrinkles and a good sharp base. A little crud gets covered up by the powdercoat...

[super6]

Looks like a cold pour, What I mean by that is your mold is not hot enough. I think buy the looks of the pot melt.. Flux more! A bit more tin may help.

[Winger Ed.]

I think your mold isn't hot enough.

Flux & stir is the only way I know of to get all the trash out,
and I have to run everything hot & fast for doing .45 cal. 405s and have them come out right.
A little extra bump of Tin should help a little too.

[flyingmonkey35]

Also attitude is a big part of it.

If your having a bad poor and it's just not improving. Turn it off and do something else.

But honestly those bullets look pretty good.

And do you mean .05 weight. + - is about normal.

Some big molds like that need to be so hot that the bullets almost have a frosty look to them.

The ryhtem doesn't start till almost the 10th to 20th cast.

Sometimes it never comes even when your having a good day.

Also as you are ladel casting. Flux and remove slag untill it is mirror shine. And don't forget to stir Evey now and then.

A good cast boolit is like wine. It will last a long time as long as the proper condition s are met.

Sent from my SM-G960U using Tapatalk

[Dusty Bannister]

You may want to discontinue the use of saw dust in the casting pot. That introduces the specks and debris you end up on the surface of the bullets. You probably are casting too hot for the lead-tin blend and that is also adding to the dross on the surface. Brass molds do take some breaking in before they build up that patina that makes mold fill out better. Not sure how many sessions you have tried or if the mold is really up to casting temperature. Perhaps someone familiar with brass molds can give you better suggestions.

When you fill the mold, are you holding the mold with the sprue plate on the side, dipping and swirling the dipper and pulling it filled from the pot and inserting the nozzle into the sprue plate and then turning the mold/dipper as one unit to pressure fill the mold? Leave the ladle in the pot between pours. We are starting into cooler weather and the ambient air temperature can result in "cold pours". Pour a generous sprue puddle. This might help smooth out your production a bit.

[coopersdad]

How hot? Last session I ran at 800, pour for two seconds, if I cut the sprue as soon as it frosts it tears the bases, so I'd wait ten seconds and cut, usually worked a bit better, and I tried pressing the sprue plate against a damp cloth 3 seconds or so as well before cutting, and then re-pour. I can't get more than three or so pours without stopping to flux, so that cools stuff off I'd guess. If I run the melt hotter that would maybe keep the mould hotter.

Last session, before casting, I fluxed with sawdust and then at least 5 times with wax, started casting and still had to stop every three or so pours. Should I do more?

Dusty, your last paragraph describes what I was at least trying to do.

[Bazoo]

Sounds like you need to flux better. The way I do it is, no sawdust, only wax. Throw in a marble sized chunk and let it flame up. If it dont flame up I either light it or just wait a spell longer. Then whenever it stops flaming I stir well with my ladle. I scoop air down into the mix. I stir and scrape the pot sides and bottom about 30 seconds. Then I switch to a spoon and scrape the ladle, and the pot sides and bottom another 30 seconds. Skim the grey stuff. Then, sometimes I repeat if I'm having trouble. I also wire brush the spout of my ladle and give it a whack on the rim of my dross can to dislodge as much of the scum as I can.

When I cast, I let the metal freefall 3/4". I also have a healthy sprue puddle. That helps the oxidized alloy to come to the top. Pressure casting helps too, But I don't pressure cast unless I can help it. I think your temperature is okay if you thermometer is correct. And your bullets are filled well. That grey scum in your bullets, not the inclusions, personally I shoot them with that. I don't find it makes any difference with ammo except for the very best.

[Mk42gunner]

I've cast several hundred pounds of boolits with a Lee 4-20 and an RCBS Ladle, although most of mine were with wheel weights not 20-1. It is definitely possible with your equipment; don't get too discouraged.

I think it is a combination of things:
1. Your alloy is probably too hot, and
2. Your mold is too cool.
3. Oh and you are fluxing too much.

This works for me. Set your alloy temp about fifty degrees over where it turns liquid. Leave your ladle in the alloy to keep it hot. I preheat my molds by resting them on top of the 4-20, (wiring issues in the old farmhouse preclude sensible use of a hotplate anywhere near my casting station).

I've even been known to dip the front end of the mold in the alloy to heat it a bit faster, if lead sticks to the mold, it is still too cool.

Your ladle has a fin on the bottom to clear a path for dipping, use it instead of skimming all your tin off.

Try this and see if it helps.

Also, I put clean ingots into my pot, and flux it once or twice with an old candle or old boolit lube (from cleaning out secondhand lubrisizers) then once I get a shiny surface, I don't flux again until I have to add alloy.

Good Luck,

Robert

[Bent Ramrod]

Some moulds just need a few sessions before they straighten out and start working right. But I think a good part of your problems are related to needless worry about what the melt’s surface looks like.

I flux the pot and skim the surface once everything is melted and then cast continuously without fluxing until the pot is depleted. Learn to use your ladle to push or sweep the surface crud away from a spot along the periphery of your pot and turn the ladle so the clean, shiny metal flows into it.

The surface scum is inevitable and forms from the oxidation of the molten lead where the surface contacts the air. You might as well leave it there, protecting the rest of the lead from further oxidation, and cast from the little clean area you keep sweeping with the ladle. Keeping your mould filled will keep it at a temperature sufficient to cast good boolits. With large castings, you may need to slow your pace to keep the mould from getting too hot.

Don’t take these tales of long casting sessions that produce boolits within 0.1gr too seriously. Integrating over all the posts some of these casting gurus make will often show that they cast within 0.1 gr but haven’t weighed a boolit in years, they just look them over with their expert, discerning eyeballs.

Like Elmer Keith said about the guy who measured his powder charges by pouring them into little piles an a piece of paper, “He had better eyes than me.”

[Goofy]

770* is your target temp w/20:1 alloy. Don't understand exactly what is causing your problem. What is your source for lead and tin? Try cleaning your mould with carburetor cleaner.

Keep working it, things will iron out. If I made it work you can as well.

https://i.imgur.com/AnC36ob.jpg

[Bird]

I like my bottom pour pot as any junk stays in the surface and does not get into the pour. I have tried sawdust, its not the way to go. Candle wax is better, but beeswax is by far the best
If the edges of the grease grooves are nicely filled out, then you have enough heat in you pot and mold. I find my larger mold likes 780 to 800 deg pot temp and a steady casting rhythm.

[bangerjim]

Those you pictured are perfect to shoot! A little ding will not hurt anything. We are not doing a model photo shoot here.

You should ONLY be fluxing in your re-melting pot and NOT your casting pot......if you are using 3x fluxed ingots. Fluxing materials can leave gunk in your casting pot and ultimately in your boolits. Wax is a REDUCER not a FLUX. It reduces the Sn and Sb back into the mix and gives you a mirror surface on the pot. I use ONLY bees wax. Sn lowers the surface tension of your mix to give you better mold fills. You could add a bit & see if that solves your problems.

Preheat your molds on an electric hot plate to FULL CASTING TEMP, not just warm!!!!!! Not on the edge of your casting pot. By doing that, I get perfect drops on the 1st pour. Buy one. It will save you tons of time in the future.

I use pine sawdust only in my re-melting pots. I stir my casting Lee 4-20's with a wooden stick to get a little carbon in there and to mix the wax in well.

Big boolits can be a bit tricky. I cast 300g 45's for my 45LC long guns and just use a bit more heat + 2% Sn.

Good luck!


banger :guntootsmiley:

[405grain]

Try reducing the temperature of your casting pot to 720 to 740 degrees. I'll bet that the grey powder that you need to keep skimming off the melt pot is your tin being oxidized by too high of a temperature. Try pre-heating your molds, either by setting them on a hot plate or resting them on top of the melting pot as your alloy is melting. Your ladle pouring, so you can pick up carbon from the sawdust with your ladle. The sawdust flux works much better with a bottom pour melting pot. Do your fluxing with wax (I like bee's wax). This will reduce the oxides back into the alloy. Be careful though, the wax can catch fire. If it does don't worry - it will burn it's self out very soon - just wear gloves while stirring in the flux and don't freak out if it catches on fire. The boolits in your picture look like the molds were too cold. Once the molds are at a good temperature and start dropping well filled out boolits, that's when you need to get into a rhythm. Remember to let the sprue completely solidify before cutting it off with the sprue plate. If you cut the sprue too soon lead will start smearing in between the mold and the sprue plate. Expertise in casting comes with experience so the more you practice the better you will become.

[GhostHawk]

Sometimes you just need to ignore whatever is on top of the melt.
Use a big enough ladle so that you still have some left in it after all cavity's are poured.

That lets you just ignore whatever is on top.


That gray powder is probably tin coming out of solution. When you do scrape and clean, save your drippings.

Try not to get tied up in all the many things that could be going wrong and just CAST.

If a fisherman was constantly fussing with his rod, his bait, his line, getting frustrated, losing his cool he is not going to catch any fish.

Sometimes you just have to cast until the pot is empty, refill it, then look at what you cast, Timing can be everything.

[mehavey]

- Wax, not sawdust for surface dipper-pour
- (large "pea"-sized clump/use dipper to repeatedly submerge into lead/scrape off powdery dross/discard
- 740-ish
- Hotter hotplate/mould temp to start

[robg]

flux well before casting .once you start casting dont flux again ,that causes more weight variation .run pot hot with big boolits.

[asecertified]

If this helps I can tell you the basics I have learned after 40 plus years of casting boolits. Clean your lead in a separate pot no matter if its a pot over a turkey fryer. Yes I use CLEAN sawdust and bees wax. Brass molds ? In my opinion for what its worth. Not the best mold for a newbie due to the break in period required. It can be extremely frustrating to get quality projectiles in a short period of time. The bigger and the heavier the boolit weight the hotter the lead has to be. Ladle casting ? Check out the bottom pour ladles at Rowell. They work great . Yes I also have Lee bottom pour pots. I also powder coat everything I cast from .22 to 12 gauge slugs. The boolits in the picture you cast ? Coat them and shoot them. What you are trying to achieve in your bullet casting sessions will take time and practice. These comments are all MY opinion.

[coopersdad]

Thank you everyone for your help. I will keep at it.