Scratched mold

[Will]

I have a Lee 38 swc mold that has scratches on top where the spur cutter hole moves across the top when opened. What causes this and can it be fixed?

[badgeredd]

I'd guess you have a burr on the sprue plate where the sprue hole is cut into it or a burr on the edge of the sprue plate. You may be abe to polish most of it out by removing (See leementing) the sprue plate and using a fine grit sand paper on a flat surface like a piece of glass gently move the blocks in an ocillating motion to remove some of it. Also do the same with the removed sprue plate. Good luck.

edd

[HeavyMetal]

Before you put the sprue plate back on do two things:

First heat the sprue plate up with a propane tourch, not cherry red just 300 degrees or so the put as lite coat of Bullshops sprue plate lube on it with a q tip and then let cool natrually.

Second take some anti size, and be careful a microscopic amount of this stuff will cover a small car, and coat the sprue bolt and the hole in the sprue plate. The trick is to get good lube with out getting it in the cavities when the plate slides back and forth on the mold top.

The sprue plate lube prevents the gauling that started the scatches in the first place I just think the anti size lasts longer as a pivot point lube!

[44man]

Believe it or not, just a lead buildup will scratch a mold. Cutting the sprue too soon and smearing lead will cut the blocks. Let the sprue harden fully and it goes away. BP lube helps but nothing takes the place of proper casting technique.

[dardascastbullets]

Your scratches can indeed be caused by lead smearing on the bottom surface of the sprue plate and the top of the mould block. They can also be caused by prematurely cracking of the sprue plate. This scenario sets up a too hot-of-a-plate rotating against the cast iron of the mould block. You may be lacking lubrication also - use silicon spray lube (just a little dabble do ya) every 500 cycles or so and your smearing will be reduced to nill.

Hope this helps ya!

[44man]

If you see some lead starting to build on top of the mold and bottom of the plate, strike a wood kitchen match and blow it right out. Rub off the lead with a few match heads. It really works!
Then Bullplate lube VERY lightly.