Two question for you

[unique]

Invariably when doing a marathon casting session I get a build up of lead on the mold surface usually on top associated with the spruce cutter.

First question, how do you remove that. I tried local heating with torch but fear warping my mold or use knife edge and scrape off but don't like doing that because mold does get scratched in the process.

Second is there a way to prevent this. I tried some light lube on surface where 'leading' occurs but that always seems to volatizes and end up in mold somehow with results of poorly filled out boolits that requires time to clear up.

Thoughts/Suggestions?

[LenH]

I use the palm of the welding glove I use for casting. I have used the edge of a paint stick to scrape the top of the mold or the bottom of the sprue plate.

I get that smear of lead when I try to cast too fast and usually when I am using an aluminum mold with a steel sprue plate. I us a dab of synthetic 2 stroke oil an
a q-tip to coat the top of the mold and the hinge bolt of the sprue plate.

I hope this helps.

[pworley1]

I cast with 2 molds at the same time. I will pour one and then the other. I open the first and repour it, then open the other and repour it, This gives the sprue time to cool enough to cut clean. This has been working for years without any build up or smear of lead.

[mdi]

Similar to LenH, but I scrub with a rough cloth, a kitchen towel, between casts when the mold is still hot. I use 2 cycle motor oil to lightly coat the mold top, underside of the sprue plate, hinges and locating pins...

[Recycled bullet]

Invariably when doing a marathon casting session I get a build up of lead on the mold surface usually on top associated with the spruce cutter.

First question, how do you remove that. I tried local heating with torch but fear warping my mold or use knife edge and scrape off but don't like doing that because mold does get scratched in the process.

Second is there a way to prevent this. I tried some light lube on surface where 'leading' occurs but that always seems to volatizes and end up in mold somehow with results of poorly filled out boolits that requires time to clear up.

Thoughts/Suggestions?

Read the thread I made called " so I'll be raining bullets"

The two cycle oil cleans it right up if you have got temperature management under control.

The torch will help you get there and if you are careful and even in the application of heat your mold will be clean and usable as it will ever be inside of ten minutes.

The synthetic two cycle oil dabbed on a 100% cotton rag is your thermometer and cleaning tool simultaneously.

[Recycled bullet]

Can you post picture of the problem?

[Winger Ed.]

I don't use a thermometer or one of those fancy PIDs,
When I see shrink holes starting to form, I back off the heat or slow down a bit.
I've found that staying right below the edge of the alloy or mold being 'to hot' greatly minimizes the effect
of both shrink holes and that 'smear'.

[MT Gianni]

Synthetic 2 cycle oil is your friend as is an old style wooden, graphite pencil. I think many sprue plates are over tightened and that one of the best things Veral Smith ever did is the hold down screw for a sprue plate.

[hoodat]

For the sprue plate, I keep a brass brush handy as I cast. The aluminum blocks -- I wonder if you're cutting your sprue too soon.?
jd

[stubshaft]

I use a q-tip saturated with synthetic two-stroke oil on it and periodically swab the top of the mold and the bottom of the sprue plate with it.

+1 - On LBT's hold down finger!

[unique]

I cleaned these up by heating with torch already so do not have any real useful pictures to share. I don't like using a torch hence the reason for my post.

I forgot about using a pencil...I did that a few times in the past and seemed to work. For those using 2cycle oil, any problem getting that on the inside of the mold? What I mean is I have put a very light dab of oil on top of mold in the trouble area and seems like I immediately get fill out problems until it gets 'burned' out and I contribute this to the oil vaporizing and finding its way into the mold.

[Minerat]

Don't use a lot, 1 or 2 drops on a q-tip is enough to do the mold and sprue plate until the q-tip is shot. Only apply when there are boolits in the mold that way you won't contaminant the cavities. If you think you have too much 2 cycle oil on the mold wipe it off before dumping the boolits.

[bosterr]

I apply synthetic 2 stroke oil with a q tip then use the dry end to take off any excess.

[405grain]

Usually, when you're getting lead smearing on the underside of the sprue plate it means that you aren't waiting long enough for the alloy to solidify before cutting the sprue. If you closely examine the sprue after casting a bullet you can watch the liquid metal solidify. Don't cut the sprue just yet, instead keep watching. After the alloy has solidified you might see it change from a bright silvery color to a more grey and flat toned color. If you cut the sprue while it is solid, but still silvery, not all the metals in the alloy may have fully solidified. Once the sprue goes through the change and the color turns a duller grey, then all the constituents of the alloy have fully solidified. Change your casting cadence so that the metal completely solidifies before cutting the sprue.

To remove metal from the underside of the sprue plate, what I've found to work best is an ink eraser. This is similar to a pencil eraser, but is usually a light grey color instead of pink. I wasn't able to find these at office supply stores because apparently no one writes with pen & ink anymore. I was able to locate ink erasures on Amazon. An ink erasure has micro-fine particles of sand embedded in it. Use an ink erasure to scrub off the lead smears from the bottom of the sprue plate and the top of the mold blocks. (mold needs to be cold to do this) Make sure to blow out any crumbs from the erasure after scrubbing the mold.

To help prevent lead build up on the sprue plate, take the cold mold blocks and draw all over the bottom of the sprue plate with an ordinary pencil. This will leave a thin layer of graphite that lead doesn't like to stick to. I use a tiny amount of 2 stroke oil to lubricate the sprue plate pivot, but I haven't tried it as a leading preventative on the mold parts, so I have no firsthand knowledge to share in that regard.

[Shuz]

To remove the lead from the underside of the sprue plate, I take a sheet of 400 grit sand paper and lay it across a piece of plate glass and sand away the bottom of the sprue plate until the lead is gone.
This method insures that the underside of the sprue plate stays flat. It also tends to sharpen the sprue hole edges.

[floydboy]

while mold is hot rub with a cool lead ingot. Smear will come off.

[Wheelguns 1961]

When your alloy and your mold are up to temp, fill the cavities, cut the sprue, and with the cavities full, wipe the top of the mold and the bottom of the sprue plate. I use a scrap piece of rag with a small amount of 2 stroke oil. I keep this rag near me when casting. Sometimes I will also wipe the bottom of the mold, and the guide, if it feels like it is dragging across. I only use enough oil to moisten the rag. This will stop the oil from entering the cavities.

[GregLaROCHE]

Make sure your sprue plate is perfectly smooth on the bottom. Straight with no burs. Tighten it as tight as you can work with it. Be sure the top of the mold is smooth and even too. Something made of wood can be used to scrap off lead residue, but you shouldn’t really need to. Lots of people like to use something to lube with. I don’t because I’m always afraid of it contaminating the mold.

[charlie b]

I also make sure the sprue screw is adjusted, almost flatten the Bellville washer. Also make sure it is flat and smooth. I do 'lubricate' it with a lead pencil on the top of the mold and the bottom surface of the sprue plate.

[farmerjim]

I cast with 2 molds at the same time. I will pour one and then the other. I open the first and repour it, then open the other and repour it, This gives the sprue time to cool enough to cut clean. This has been working for years without any build up or smear of lead.

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