Question on new Lee 457 405 mold

[BeemerMark]

Just picked up a new 457 Lee mold. After boiling and lubing the pins I tried to see how it would cast. Will not fill out. So I found the needle was going to score the vent lines.

Problem is, there is NO vents in the molds.

Is this normal? I don't think so, but being Friday night I thought I'f ask here before I try Lee Monday.

[Maven]

"Problem is, there are NO vents in the mold."

Actually Mark, there are. They're spaced between the vertical locating ribs on each mold half. You can open or slightly deepen that space* with a jeweler's file if you wish, but I don't think poor venting is the problem. Rather, casting a too low a temperature with that particular mold will most definitely -> poor fill-out. Moreover, while this may be heresy to some, I'd recommend smoking each cavity and the base pin with a wooden match or two. Do this when the mold is hot so as to avoid condensation in the cavity and the ensuing spatter.

In sum, check your alloy to see that you have 1% - 2% Sn in it; raise the furnace temp. to 800 deg. F; smoke the mold and base pin; use a casting ladle/dipper rather than the bottom pour feature of your furnace.



*When the mold is cold, open the sprue cutter and look directly down at the top of the mold. You will then see the main opening + 2 much smaller holes. The latter 2 are the vents.

[BeemerMark]

"Problem is, there are NO vents in the mold."

Actually Mark, there are. They're spaced between the vertical locating ribs on each mold half.

*When the mold is cold, open the sprue cutter and look directly down at the top of the mold. You will then see the main opening + 2 much smaller holes. The latter 2 are the vents.

Nope no holes. No vents. Can run my thumbnail across the face and it's smooth as a baby's bottom.

[fryboy]

do you have the new style mold or the old style ? the newer style they're much less pronounced , more like faint milling lines than true vent lines , ye olde style they were often barely distinguishable , these are the ones that the needle trick works on
have a good magnifying glass ? it'd about be a must , if there arent any at all ( even faint ones ) i'd call lee , or conversely you can make some if you wish ,i'd suggest a straight edge for such an endeavor

[John Boy]

... first I've heard of a Lee mold with no vent lines. I cast with several old Ideal's with none. Produces perfect bullets

[BeemerMark]

I got a few good boolits, but had to get the alloy and mold real hot so it ran like water, then tip the mold and kept poring until it harden. Slop all over. Like I said I can run my thumbnail across the surface and not feel anything. Thumb nails are very sensitive to any type of groove or crack, even ones you can't see. I'll call Lee Monday. See if they send me another one without sending this one back. Given the cost of a 2 cavity mold it isn't worth the postage to send it back. I'll try making my old vents with a scribe.

[JonB_in_Glencoe]

I just bought that mold, with a handfull of other New Lee 2 cav molds in hopes of finding one that'll work with my 11mm French Gras.

I assume my mold was probably made in the same batch as yours. The vent lines are nearly invisable to the naked eye and feel smooth as a babies bottom :) But they are easier to see with a close up digital photo. They are there and they are tiny. I haven't cast with this mold yet, But I have cast with a couple other similar molds I just got (454-298 and 457-340) and those vent lines looked the same as the 457-405 shown below. I did have some fillout issues, what I did was break the seem (at a 45º angle) on top of the blocks with an eze-lap file, basically making one large vent line, as shown below in the before and after photos.

http://i640.photobucket.com/albums/uu127/JonB_in_Glencoe/cavitiesventlines_zpse26f3f17.jpg (http://s640.photobucket.com/user/JonB_in_Glencoe/media/cavitiesventlines_zpse26f3f17.jpg.html)

BEFORE
http://i640.photobucket.com/albums/uu127/JonB_in_Glencoe/edgefromfactory_zps8beac705.jpg (http://s640.photobucket.com/user/JonB_in_Glencoe/media/edgefromfactory_zps8beac705.jpg.html)


AFTER
http://i640.photobucket.com/albums/uu127/JonB_in_Glencoe/edgebrokenwithezelap_zpsc530a81b.jpg (http://s640.photobucket.com/user/JonB_in_Glencoe/media/edgebrokenwithezelap_zpsc530a81b.jpg.html)