Lee six cavity mold misalignment?

[jmac2112]

Hi,

I have just started casting boolits using a Lee six cavity mold, 452-230TC using WW alloy. When I mic the boolits, I get some funny readings. Typically I'll get about .452 side to side (i.e. not in line with the part). When I measure the diagonal just to one side of the part, I get .454, while if I measure just to the other side of the part I get .450. All six boolits from a casting measure in a similar way, with very minor variations.

If I put the mold blocks together with a straightedge across either end and hold it up to a light, I can see that the blocks are not quite aligned, which may or may not be significant.

Does this sound like a misalignment problem? If so, is there a fix other than sending the mold back?

Thanks!

John

[HtNRun]

Following.

My experience, I was pulling measurements from dead on .452 all the way to .460. I was wondering if I was running those aluminum molds too hot. Using WW alloy as well from a lee 20# bp.


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[Garyshome]

I usually size them after casting. Its tough to keep the Lee pot at a constant temp. But that shouldn't make that much difference. I would contact Lee's tech support and ask them. They have great customer service.

[Larry Gibson]

Look closely at the alignment hole. Many times they get dinged and develop misaligning burrs by not having the blocks far enough apart when knocking the bullets out.

Also don't hold the sprue plate handle when pouring, only hold the mould block handles. Holding the sprue plate handle will/can also cause a misalignment of the blocks and cause odd out of round and oversize measurements.

Larry Gibson

[jmac2112]

OK, thanks for all the advice/commiseration! I really need the boolits to be bigger in any case, so I will probably end up enlarging the cavities. I'm seeing a number of threads on here about how to do that. That should hopefully take care of any misalignment as an extra benefit.

[Larry Gibson]

You might also add 2% tin to your WW alloy. It will give you better bullets. The tin gives better fill out for more consistent diameter and larger diameters also. Also cast with the alloy around 720 degrees +/-.

Larry Gibson

[matrixcs]

This variation adjacent to the parting line is always caused by miss-alignment of the blocks. one or both pins may not fully engage with the sockets or there are burrs or dents in or on the pin or socket. I have fixed a couple of the six cavity molds by moving the steel socket to engage fully. I had to rework the pins and sockets after they were buggered up when I loaned the mold to a friend who has a habit of slamming the mold shut. (all his molds need work)

[jmac2112]

Thanks, Larry and matrixcs! A couple of follow-up questions:

1) Larry: Where to get tin? I've seen some sort of "super hard alloy" from Rotometals. Or should I be able to get straight tin at the local recycling yard?

2) Matrixcs: When you say you moved the steel socket to engage fully, do you mean that you drove it a little further out from behind? All I can say so far about my mold is that I used to be able to see a little light through the seams when it was closed. Then I clamped it in my vise (with soft jaws), and now I can't see light any more.

Thanks!

John

[TexasGrunt]

Rotometals sells tin, you can find it here in the Swap section or you can salvage pewter.

[gundownunder]

You get what you pay for. I would recommend replacing the Lee mold with a quality mold.
I've bought a couple of Lee molds and they were both consigned to the trash can in very short order.
Both were out of round, the second one was a six gang 358-125 RF which I only bought a couple months ago, and it went from .357 to .361 depending on which side you measured from. I couldn't even close it properly until I de-burred it.
Sorry, but Lee Precision is precision in name only. In future the only Lee stuff I will buy is stuff that doesn't need to be precise.

[matrixcs]

Thanks, Larry and matrixcs! A couple of follow-up questions:

2) Matrixcs: When you say you moved the steel socket to engage fully, do you mean that you drove it a little further out from behind? All I can say so far about my mold is that I used to be able to see a little light through the seams when it was closed. Then I clamped it in my vise (with soft jaws), and now I can't see light any more.

Thanks!

John
Even when no light is visible the blocks can slide one way or the other if the pin is not fully seated in the socket.
The method I used was to clamp the blocks tightly in a vise leaving 1 end where the pins and sockets exposed
then using a large c clamp and pins large enough to fit in the holes for the pin and socket to compress the pin and socket to be fully engaged.
then repeat on the other end.
one of mine was missing engagement by .020 before I seated them using this method.

[JohnH]

You can get lead free plumbing solder at Lowes or Home Depot. A pound will run about $25.00 and is 95% tin and 5% antimony