smearing problems

[archeryrob]

Okay, i got really frustrated today. I have been having this trouble with my 11bhn lead since I started casting bullets for the rifle or pistols. Never had any of these issues with my pure lead for BP shooting. I had smearing with 124 truncated cones for 9mm with smearing (Aluminum mold). Did some 30 cal bullets for the 30-30 and had a lot of lead pieces sticking to the MP mold that I still need to clean off (Aluminum mold).

Today I use the same lead alloy and melt for casting 147gn RN BB bullets for the 9mm with the MP mold (Brass). I have heated this mold over and over until it aged up good color wise for the patina. It started casting well as I heated on the hot plate and then with the lead a few runs. I started getting a coating sticking tot he sprue plate. It would be like the edge of the sprue puddle would leave a ring. I had some base fill out problems with the lead being 625 got up to 675 and mostly went away but not completely. I would fill the mold and watch the sprue solidify and count yo ten and bang the sprue plate open. If good into the bucket in not on the towel. The lead got up near 700 and I counted to twenty before opening the sprue plate and it seemed good. Then I got smearing. I got out the propane torch and heated the sprue plate and it got hot enough and I used a towel and off it came. A slight trace could be seen still of where it was before. The mold I heated longer and could only get some off. I tried to cast another one and it smeared awfully and I counted to over 30 on this one.

Maybe the mold was too hot? I read on here make it hot and go.

Maybe this alloy has trash in it?? I cast a while and keep getting a scum on the surface. I scrape it off and keep casting fluxing doesn't seem to change it. My pour ladle has seemed to be covered in lead trash lately and adding the ladle to the hot lead pot makes more scum surface.

Maybe something else? I am wondering if I did something wrong or I have contaminated lead with some of stuff like zinc or other metal. I have no troubles with pure lead and this stuff just is not working.

Also, once I solve this how do I clean all these molds and the pot?

[Ben]

By looking at the underside of your sprue plate, it looks like you have antimonial smears. Most likely caused by the Sprue Plate being too hot when you open the mould.

You can slow down your casting, you can place a wet sponge on the sprue plate before opening the mould to minimize this.

It may also be helpful to clean the underside of the sprue plate and put on a VERY thin film of synthetic 2 cycle oil on the sprue plate prior to casting again.

Sounds like there is a real chance you are casting with alloy that is too hot.

[358429]

I do not recomend using your heirloom cotton rags for this... so here's what I did.

Get clean white cotton rags that are never going to be used for any thing else, cotton Rags from the hardware/parts store would be okay.

Pour on some 2-cycle oil into the rag, unfold the rag over and over so it absorbs.

The rag is going to start out blue but it'll start turning gray as the rag begins to burn from regular use.

Get the mold up to full temperature even slight overheat with the propane torch and then just scrub/wipe the mold with the oily rag and it will become clean!
Scrub the bullet cavities! Scrub all sides of the sprue! Scrub everything!

(Optional)
When you're done go drink a beer and look at how good it looks, let it cool down 30

minutes should be about right, you want to be able to touch it with bare fingers unless

you feel like being frisky,and using those tiny Allen keys with leather gloves,

disassemble the sprue and then polish the bottom of the sprue and the top of the mold blocks with a strop and Jeweler's Rouge if you've got it.

Check with your fingernail or a q tip and make sure that there's no burs on the Leading Edge of the sprue and also and the holes where you pour the lead.

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[archeryrob]

I saved a 2 cycle oil bottle to treat 2 gallons of fuel I saved just for lubing molds. I was oiling under the sprue on top of the mold and the mold alignment pins with a Que tip. The spure plate cleaned right up under the torch but the mold did not seem too. I thought I put lots of heat on the mold but maybe I quit too early? I went back to casting any maybe the sprue was super hot.

So recommend the best leaning way for the mold(s). Heat and oily cloth?

What temp should I cast at? I was having fillout problems at lower temps and getting a better run and then this?

[358429]

Yes you want the mold to steam mildly, when you wipe it down. The sprue plate is going to look like a old blued remington 1911 when you wipe it down, at least until It gets dirty again. Gorgeous to cast in the Sun when it looks like that, then just periodically wipe it down as maintenance, also helps with cooling if you overheat.

I like to just slightly overheat it on purpose, wipe it down and then start casting. Usually by the third series of castings the mold cavities are clean and I'm getting good excellent bullets.

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[358429]

Temperature is going to be trial and error. Brass Mold needs a higher alloy and mold temperature.

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[Conditor22]

I do all my casting between 700 --720° (750 for pure)

For fill out problems, add a little more tin/pewter. Pre heat the mold on a 400° hotplate.

Smearing is a heat and lubing issue. Wait until the sprue frosts over before you open THE SPRUE PLATE.

synthetic 2 cycle oil fuel additive is your friend

after you cast your first boolit, cut the sprue but don't dump the boolit.
Dampen a q-tip with synthetic 2 cycle oil fuel additive, swab the sprue hinge, top of the mold, and bottom of the sprue plate. Work the sprue plate back and forth for a few seconds then wipe off all the excess oil. open the mold and dab the alignment pins and holes with what's left on the q-tip [DON'T GET ANY IN THE CAVITIES]

Het up the mold and sprue plate, then with a lead ingot or sharp piece of wood rub/scrape off all the smeared lead. DON'T USE METAL.

OR You would submerge the mold in the pot, when it gets hot enough all the lead will just slide off.

[archeryrob]

I let the sprue plate frost over and when the dimples over the bullet hole settle I start counting. When I got the smear I did 20 seconds. So I was wondering if I just got the mold too damn hot.

it's too hot to mess with it now. I am off between jobs so I can heat and torch the molds to clean them and try again tomorrow. I just want to make sure I do it correctly.

I thought the higher temp worked better too but I had issues. Maybe I just need to pause longer.

[gwpercle]

I've been reading all this with interest ... there is such a thing as having a mould too hot and having alloy too hot .
I don't put my mould on a 400 degree hot plate , I just rest it on top of the pot and bring alloy to 750 degrees and start casting .
When sprue's frost over , hardens , I count to seven by 1000's , then open the mould .
Mould lube on top of blocks and underside of sprue plate ... a very thin coat .,, easy to over do .
Cast untill boolits start to get a frosty sheen , cut temp. back to 725, cast them right at a light frost .
I'm not sure if a hot plate at 400 degrees is a good thing ... try old school no hot plate and see if that helps .
I think you might have things too hot and that's causing some problems .

Casting has a tough Learning Curve ...but the only way to lean how to cast boolits is to cast boolits .

Clean off all the smears , and lube ...whenever you see a smear ...stop and clean and lube . I use an old coarse piece of burlap with a little oil , to scrub the hot mould smears . It will only get worse and in bad case it will damage an aluminum mould top ...I've done it .

Keep on ...don't throw in the towel yet , you will get the hang of it .
Gary

[Dave W.]

The long and short of it is that your mould is too hot. The lead is not having enough time to solidify, what you are seeing is the soft lead smearing and adhering to the surfaces. On of two things needs to happen, either wait longer before opening the sprue plate or cool the mould off. Personally I would do both. The sprue plate should be a little hard to open, it needs to cut the sprues off cleanly, opening easily means the lead has not cooled enough to get hard. Hang in there, it takes a while to get the feel for it.

[archeryrob]

I heated the mold back up on the hot plate and then took the torch to it. The sprue plate cleaned up really nice. The oily rag did make it look like gun metal. The mold took a lot more heat and the smears from the second and third cavity closest to the handle kind of turned dark colored like a brown. I heated it some more and oily ragged it and no change.

I ran a pot of lead with my dip ladle and got about a pint of good bullets and sorted them and the few base no fills or heavy wrinkles went back into the pot. It seems my largest problem was my own damn patience. I have a 2x3 piece I use to set the bowl for skimming trash into and resting hot stuff on. I would fill the mold once I got good fill out and no winkles and rest it on the 2x3 for thirty seconds or so. I'd have some coffee since its too early for beer. Then bang the sprue off on the towel and dump the bullets in the bucket of water.

Thanks for the help. No pictures as I do not have a phone. In between jobs. Quit the last and start the next on on the next Monday. Phones are supplied by both companies and not buying burner for a week.

[Wayne Smith]

The other option is to have a wet rag or sponge on your casting bench. If you get these smears your opening your sprue plate too soon - the lead is not solid. Turn your mold over and put the sprue plate on the wet sponge/cloth to cool it, open sprue plate, and dump.

[Burnt Fingers]

Are you sure of your lead temps????

I run my pot around 700-720 when casting with brass 6 cavity molds. I NEVER have to wait a 20 count after the lead has frosted over. Maybe a five count at the max.

My sprue plate tops never look like the ones you have pictured. Nor do the bottoms.

[archeryrob]

It is all good now. I casted another pint of 9mm bullets this morning to make more rounds. I was running over 700 and let it rest on the 2x3 for 20 or more seconds and never had any smearing again. I did have a touch of lead in the fill outs neat two cavities and one at the bottom. After finished I put the torch on them and rubbed the rag on them to clean it up to cool down and be put away.

[Conditor22]

I set my molds on a 1x6x12" piece of steel bar to cool.



or



Setting my molds on a hot plate to pre-warm allows me to get good boolits on the first or second cast.

[gwpercle]

I set my molds on a 1x6x12" piece of steel bar to cool.

Setting my molds on a hot plate to pre-warm allows me to get good boolits on the first or second cast.

But do you pre-heat the moulds to 400 degrees ?

[bruce381]

I put my hot plat to high whatever that is then the pot is 700 good from the start and if too hot SLOW down and use 2 cycle oil as needed.
AL molds need a lot of heat to start iron not as much.

[Conditor22]

I set my hotplate to 400°, I have a 3/8" piece of steel over it and set my molds on the steel. I turn the hotplate on with the molds on it the same time I turn my pot on. It works -- I never measured the temperature of the molds.

[Cowhide]

A couple of questions to responces given in this thread

disassemble the sprue and then polish the bottom of the sprue and the top of the mold blocks with a strop and Jeweler's Rouge if you've got it.

Check with your fingernail or a q tip and make sure that there's no burs on the Leading Edge of the sprue and also and the holes where you pour the lead.

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When you do the leather strop with Jewelers rouge on it. Do you go in just one direction? And if you develop a burr what do you use to remove the burr? Is burr removal different if it is on the sprue plate verses the mould cavity rim it self?

[358429]

A couple of questions to responces given in this thread

disassemble the sprue and then polish the bottom of the sprue and the top of the mold blocks with a strop and Jeweler's Rouge if you've got it.

Check with your fingernail or a q tip and make sure that there's no burs on the Leading Edge of the sprue and also and the holes where you pour the lead.

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When you do the leather strop with Jewelers rouge on it. Do you go in just one direction? And if you develop a burr what do you use to remove the burr? Is burr removal different if it is on the sprue plate verses the mould cavity rim it self?

The polishing of the parts is to improve fitment of the parts.

It needs it only if it needs it.

Have you polished parts before? Adjust the direction of polishing to leave a smooth uninterrupted surface.

The de-burring is to remove any sharp edges that may scratch the mold blocks.

Do your mold have sharp edges or scratch marks?


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