problem base of boolit

[Alberta Separatist]

base of the boolit has fins protruding after being cut with the sprue cutter.
do I need a new sprue plate?

[DHurtig]

Fins are normally a sign that the mold is not fully closed. Dale

[prs]

Fins running along the the seams where the mould halves mate, see above response. Fins perpendicular to the base could be lead smearing (cutting too soon --- I doub't it) or bend spru plate (cutting too late). Lee or other large multicavity moulds with spru handle, cut spru soon as they freeze. Shoud take very little pressure. One or two cavity moulds, use gloved hand. You may need a new plate.

prs

[ku4hx]

A couple of pictures might be helpful.

[runfiverun]

if it's on the cavity closest to you the plate is too tight.
if it's the one furthest from you [closest to the screw] tighten it a little.

[303Guy]

There are the mechanical causes like has been suggested. Alloy can do it. High temperature and do it. Are there only base edge feathers and are those even all the way round? I've had an alloy that would flow into the vent holes but I don't recall much in the way of edge feathering - a little I think. Those wiped away with a finger. Is this a new development and did it coincide with a new alloy batch? Ladle cast or bottom pour? Bottom pour can put a lot of pressure in the mold.

[popper]

If it is a smear and on one side, it's cutting too early or sprue plate. If all the way around, it's something else. If it is thin and brushes off, no problem. You could cut it and then size or size and leave it.. Bet they don't drop easy either.

[Alberta Separatist]

thanks for all the suggestions.. I e mailed Lyman and they responded with " buy a mould rebuild kit"; which indicates a new sprue plate.

I think that maybe my alloy might be contaminated with some zinc wheelweights; but not all my boolit bases have burrs; some cut perfectly clean.
I think I'll try the loosening the tension on the plate before I contact Lyman.

I'm also going to use the Lyman super moly spray lube on the mould; it does wonders for the mould release.

thanks everyone!

[runfiverun]

stop.....do not spray it unless you want smaller boolits.
a little lapping will make them drop much easier.

[leadman]

The Lyman mold rebuild kit contains a thicker sprue plate that works better then the old thin plate. Just make sure the sprue holes are tapered all the way to the bottom or the sprues can stick in the plate.
If you tighten the screw for the SP too much it will tip it up. Can be seen if you look at the mold from the side at eye level.

[Alberta Separatist]

very interesting... thank you leadman!

[Alberta Separatist]

purchased a mould rebuild kit at Wholesale Sports here in Calgary; problem solved.:-)

[codeNshoot]

I acquired an older ideal mold that fills out perfectly with a pour from the ladle but will build up around the bases when "pressure" poured.

I don't really see it as much of an issue, but I'm sure a rebuild kit wouldn't hurt.

Tried it loose, tried it tight. Results only varied with pouring method.