LEE mold annoyance

[rickt300]

I have a 35-200 mold I have owned for 5 months or so. This one has far too many rejects and I can't figure it out. I have cleaned and oiled it several times but the problem still persists. fully half or a bit more of the bullets come out with a little "c" mark on one of the bands between the lube grooves almost dead center. Mold cleans up beautifully. Any ideas? Send it back?

[Rickf1985]

Have you called Lee? They will certainly help you out and if it appears that the mold is defective they will replace it. I don't know if they will refund your money due to the time you have had it but if it is bad they will replace it. I am assuming the mark is not from the oil?

[rickt300]

No I detail cleaned it and applied 2 stroke oil in the correct fashion. Might be a vent line is plugged, think I will get it out and take a good look at it.

[kungfustyle]

Tin, heat, cadence. You need to be using 1 to 2% tin in your alloy. Increase the heat in the pot, 750 or so. Increase the cadence that you pour. Go till you get frosty bullets and see if they still have this "c"

[Dusty Bannister]

Bottom pour or ladle pour? No mention of your method of cleaning or if you have heat seasoned the mold. We have to presume that you have no other Lee molds giving you this issue. What is the casting history with this mold. A flaw in a bearing band might just be slow fill or tilting the mold when filling. As always, a photo would be helpful in seeing what the defect actually is.

[mehavey]

Unless you can 'C' [pun intended] a defect in the mould where the aberation occurs in the bullet, it ain't the mould.

- No oil to start.
- Toothbrush scrub with dishsoap under hottest-possible water from tap (maybe 2-3 times)
- BrakeCleanSpray/Dried/preheated
- Strong-stream Ladle pour (not contact) w/ sprue puddle

See if the defect goes away.


*If the Lee 358-200RF, I'm shooting the same one.)

[waksupi]

Tin, heat, cadence. You need to be using 1 to 2% tin in your alloy. Increase the heat in the pot, 750 or so. Increase the cadence that you pour. Go till you get frosty bullets and see if they still have this "c"

This. Aluminum molds need run hot.

[mdi]

In one cavity or all? Is the "C" the same every cast, on every bullet from one cavity? Or is the "C" different, from different cavities? I agree with mehavy; "Unless you can 'C' [pun intended] a defect in the mould where the aberation occurs in the bullet, it ain't the mould."...

[Bloodman14]

Cast 5 or 6 and take a pic of them lined up so that we can 'C' what you are talking about. Pics always help!

[Stopsign32v]

It's not hot enough

[243winxb]

For Lee mold problems-

[megasupermagnum]

This is not a problem of cleaning. There is nothing wrong with the mold. While tin helps, you can cast pure lead just fine in a Lee mold.

There are only two possibilities here. Temperature, or fill rate. Either your pot temp is too low, or you casting cadence is too slow (mold too cool). Less likely, but definitely possible is you are filling the mold too slowly. You want them to fill fairly fast, you want that inrush of lead to provide some pressure to fill the mold. Also highly unlikely is your spout is too far from the sprue plate, which makes the lead lead too cool before it is in the mold.

[Winger Ed.]

Raise the heat, speed up your fill rate with the mold angled down a little, and going from the front cavity to the rear.
Leaving a generous sprue puddle helps with keeping the heat up too.

I get 'em hot enough to frost a little, then back the heat off until it stops.

[TurnipEaterDown]

Hard to say what the 'c' is when we can't see it. (If needed, apologies for the say can you see reference...).
I would sometimes get odd little 'c' shaped marks on bullets from a LEE mold or two I had, and I found that my trouble was contaminant related. Oxides / hard particles, on surface of the melt.
I have also had odd worm track like marks when temp was too low when lead was flowing in the mold cavity. Solved that w/ higher pot temps, or putting the ladle spout up to the sprue hole if I remember right. This, like a comment above by MSM.
Pictures would be good.

[quilbilly]

This is not a problem of cleaning. There is nothing wrong with the mold. While tin helps, you can cast pure lead just fine in a Lee mold.

There are only two possibilities here. Temperature, or fill rate. Either your pot temp is too low, or you casting cadence is too slow (mold too cool). Less likely, but definitely possible is you are filling the mold too slowly. You want them to fill fairly fast, you want that inrush of lead to provide some pressure to fill the mold. Also highly unlikely is your spout is too far from the sprue plate, which makes the lead lead too cool before it is in the mold.

What he says! Also you could try a light bit of smoking to the mold after it is already hot. That has helped for me on occasion.

[BLAHUT]

More heat

[ChuckO]

I have noticed the "C" mark on bullets cast in a 6 cavity Lee mold before. When opening the sprue plate I have noticed a small "crumb" of lead left on the sprue plate in the pour hole. If I don't remove this bit of lead then it gets washed down into the bullet cavity on the next pour and leaves this type of mark. If I remove this bit then the bullets cast don't seem to have the mark. I think that this bit of lead is only partially melted when the next bullet is poured and that leaves the mark.

I was getting this on about 30% of my casts with a Lee 6 cavity 356-120-TC mold if I did not knock off this bit of lead. When I started checking after each pour and removing the bit of lead I was able to cast over 600 bullets without a mark.

[oley55]

I have noticed the "C" mark on bullets cast in a 6 cavity Lee mold before. When opening the sprue plate I have noticed a small "crumb" of lead left on the sprue plate in the pour hole. If I don't remove this bit of lead then it gets washed down into the bullet cavity on the next pour and leaves this type of mark. If I remove this bit then the bullets cast don't seem to have the mark. I think that this bit of lead is only partially melted when the next bullet is poured and that leaves the mark.

I was getting this on about 30% of my casts with a Lee 6 cavity 356-120-TC mold if I did not knock off this bit of lead. When I started checking after each pour and removing the bit of lead I was able to cast over 600 bullets without a mark.

^^^That right there may very well be a stroke of genius! Well at a minimum something to consider and possibly experiment with. Thanks..

[rickt300]

Well when I get around to casting my fall bullet supply I will check into all of these possibilities. Low Temperatures are not the problem but possible contamination of alloy might be. I can cast perfect bullets out of my NOE mold which I alternated with when using the LEE mold. Both aluminum and both 35 caliber molds.

[Dusty Bannister]

But the Lee molds now have a reduced mass by milling off part of the bottom of the blocks for the 2 cavity molds. This would not be relevant if you are using a Lee 6 cav and a NOE 4 or more cav mold. Those would have similar block mass to deal with.