First results

[DeadWoodDan]

I noticed on a few the base of the boolit was rounded not square and some the grease groove wasn't pronounced. I'm curious if i'm not letting them cure in the mould long enough before taking out? Does it matter how long you wait after you pour before you open the sprue plate? I once read to leave a steel mould full to prevent rust?? to they cut the sprue off and just leave mould closed? OR can you leave the sprue in place???

NOE 311-165gr GB
LEE 4-20 furnace
Alloy = WW with 40/60 solder added

Would like some feed back on pictures please.

thanks
DWD

[Larry Gibson]

Alloy is probably not hot enough.

Open the adjustment to let the alloy come out and into the mould faster with more pressure.

Leave a good sprue on top of the plate, even if it runs over.

Let it cool until the sprue hardens. You can see it shange texture and color as it hardens. How long depends on alloy temp, mould temp, ambiant temp where you cast, air flow if any across the mould and how fast you are casting........

I once read to leave a steel mould full to prevent rust??

This too depends; on how humid it is where the moulds are stored, the type of flux used and how well the alloy seals the cavity. Where I live in the Pacific NW it doesn't work that well.

Larry Gibson

[DeadWoodDan]

How tight does the sprue plate need to be tightened down? I was getting a little smear on top of the mould and contributed this to plate not being tightened down enough and / or not waiting long enough before opening.

Thanks for the help

[runfiverun]

changing the sprue plate tightness can change the venting on the mold.
you have to be careful doing it, if you tighten it a titch too much you then have a loose problem on the cavities away from the screw.
you want it flat.
sometimes this is loose [and swings on it's own weight] and sometimes it has a little friction on the mold top.
i have seen it change as the mold heats up too...

use the bullplate you got with the mold.
number 5 is what you are looking for from the noe molds.

[stubshaft]

The only thing that I can add to Larry's response is that you may be pouring too slowly. I can have everything going right for me when casting but if I pour too slowly I sometimes get a rounded base.

[runfiverun]

the long boolits seem to like the alloy shot straight into the hole.
then a good sprue to keep the plate hot.

[williamwaco]

Alloy is probably not hot enough.

Open the adjustment to let the alloy come out and into the mould faster with more pressure.

Leave a good sprue on top of the plate, even if it runs over.

Let it cool until the sprue hardens. You can see it shange texture and color as it hardens. How long depends on alloy temp, mould temp, ambiant temp where you cast, air flow if any across the mould and how fast you are casting........

I once read to leave a steel mould full to prevent rust??

This too depends; on how humid it is where the moulds are stored, the type of flux used and how well the alloy seals the cavity. Where I live in the Pacific NW it doesn't work that well.

Larry Gibson


DITTO + 1.

Insufficient sprue is my personal number one cause of rounded bases.

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