Mold Frustration... HELP!!!

[ChuckS1]

Okay, this one has me stumped and need some help.

I just picked up a single cavity Ideal 429348, the 180 grain fill wadcutter. Cleaned it three times with brake cleaner and then tried it with WW alloy. Once it's warmed up, it'll cast fine, but I have to have my 10lb Lee pot set at the highest temp setting and cast pretty quick to get good fillout on the driving bands. The base edges will be nice and sharp for maybe 10 casts or so, but then the base edges will round and I get incomplete fillout of the base. The driving bands stay sharp. I've tried a 10 count with the mold open to let it cool a little between casts and sometimes (seemingly randomly) that'll work, then I'll go 5 or 6 casts with rounded bases, then it gets nice and sharp bases again.

Never had that happen with my other molds. What do you guys think? Mold and/or melt too hot?

TIA.

[revolver junkie]

ive had this problem with a lee mould check your vent lines they may need a little tweaking the next thing i would try is trying to get the stream of lead right over the champhers for the sprue on the sprue plate that usually works with my lee mould other than that i bet one of the more expeienced members will probably put me in my place

RJ

[MT Gianni]

I agree that it is venting and advise you to loosen the sprue plate and see if that improves venting. Some almost need to swing under their own weight.

[ChuckS1]

Venting may be the problem. There are only 3 vent lines; one on the bottom of the cavity that goes straight down and two more that go out at 45 degree angles from each bottom corner of the cavity. Not the many horizontal vent lines on my other molds.

The sprue plate is a little tight. I'll loosen it and see if that helps.

[ChuckS1]

Loosening the sprue plate fixed it. Thanks for the suggestions.

[happy7]

Another fix is to LIGHTLY run a file on a 45 degree angle along the top edge of each mold face. You want to remove just enough metal to make a v shaped ventline between the blocks. The important thing here is to not overdue it. You don't want to remove too much. I sometimes do it while in the middle of casting. This way, I can remove a little, cast, remove a little more, etc., till I have just enough. In any case, don't remove more than a normal vent line. You don't want to make it big enough that lead can flow into it.

[WHITETAIL]

:Fire:Chucks1,You see these guys and gals know their stuff!

[sharpshooter3040]

Okay, this one has me stumped and need some help.

I just picked up a single cavity Ideal 429348, the 180 grain fill wadcutter. Cleaned it three times with brake cleaner and then tried it with WW alloy. Once it's warmed up, it'll cast fine, but I have to have my 10lb Lee pot set at the highest temp setting and cast pretty quick to get good fillout on the driving bands. The base edges will be nice and sharp for maybe 10 casts or so, but then the base edges will round and I get incomplete fillout of the base. The driving bands stay sharp. I've tried a 10 count with the mold open to let it cool a little between casts and sometimes (seemingly randomly) that'll work, then I'll go 5 or 6 casts with rounded bases, then it gets nice and sharp bases again.

Never had that happen with my other molds. What do you guys think? Mold and/or melt too hot?

TIA.

I have the same mould and have had the same problem. The problem is the venting. Take a jewlers loop and examine the vent lines in relation to the cavity. the vent lines are cut first then the mold is cherried. When the cherry cutter cuts the cavity the cutter closes off the vent lines with a tiny burr. Use exreme care and an exacto knife to open them back up. Also take a needle file and deburr the outside edjes as someone else suggested. the top of the mould where the sprue plate slides also needs to have the edge broken on it also. When opening up vent lines place the block half in a vise and lightly push the exacto blade toward the cavity removing the burr on each vent line. Put a piece of leather in the cavity just in case you slip so you don't scratch the mould.


Doug