Casting issues/questions

[CLP]

Finally had a whole weekend to enjoy some of my hobbies.

I started by trying out casting 38 cal (RCBS 158gr SWC) in Lyman #2 alloy.
The two questions I have:
I tossed exactly two of these same bullets from a previous casting session into the melting pot because they had wrinkles. I used those bullets to try out my lubrisizer. I also put gas checks on those two. I put about 5lbs of #2 alloy ingots into my Lee furnace/pot. I assumed the gas checks would just float to the top and I could skim them out. There was a little bit of dross, but no gas checks as far as I could see. It wasn't hot enough to melt copper. What gives?
The main question I have about casting these bullets is that some of them come out with some haze on them. Most are uniformly shiny, but there are some that are mostly shiny but have splotches of haziness. Is that from removing them from the mould too soon? Is that an indication of the lead being too hot?

Lastly, I cast some .570 ball for my 58cal Hawken using pure lead. I tried using a ladle to cast these and don't have a good ladle pouring technique down yet. In my frustration I opened the mould too soon which left a tiny splotch of lead between the top of the mould and bottom of the sprue plate. I haven't attempted to remove it. What's the best way? I don't want to ruin this otherwise brand new mould.


Thanks for your advice!

 

[mdi]

I'm sure the gas checks are in there somewhere, they won't melt at molten lead temperatures. I have removed lead spots from my molds with a piece of denim cloth. I heat the mold to casting temp, open the mold and scrub the surface with the denim. For really stubborn spots (and I only suggest this to be used with ultra-care) I have used a bronze brush (the tooth brush size). Lightly brush the area of the spot, just enough to remove the offending lead oops...

 

[blarby]

The gas checks are in there. Stir well, and sift through the dross.

I often find GC in my dross, to the side of the casting area. They will not be that shiny copper color after a trip through your oxidizer...erm...lead pot. They will at best look like old pennies. Can make them hard to spot.

As for the mould residue.... Are the spots large enough to have a raised edge to them ? If so, those plastic dental picks work really good on a cold mould- not a hot one.

On hot moulds with this problem, I use wooden toothpics. Works pretty well, although you will break more than a few of them- the toothpics- but who cares, they ARE toothpics.

If they are "flat" spots that do not obstruct the closing of the sprue, you can use any type of serrated plastic to abride the lead off. I've used everything from the edge of shotgun hulls, to dixie knives.

The main reason you want these spots off is that they attract more spots ! They allow a wider and wider gap between sprue cutter and mould.... and the cycle continues.

If its really stubborn ( ive had a few of these) Start by heating the mould up, with the sprue removed. Reinsert the sprue cutter screw !!!!!! Overfill the mould so that the runoff contacts the spot, and tap the mould at whatever spot you normally do to eject the casting until the spot is removed. Basically you are melting it off by contact with the other hot lead. This can be a little messy at first, but once you know how to do it, you'll be happy you learned how. Dont let the lead overflow BOTH sides of the mould, or you will have new problems. Tilt it to the side away from the sprue cutter bolt so the river flows away from the moving parts. An olde tymer caster tought me this one, and its like voo-doo withcraft it works so well. Not something you can do during a "normal" casting session, though.

Once the spot is off, reinstall the sprue cutter correctly, and lube it ! Lube it well, wipe off the excess, clean the cavities with a q-tip, and cast a few bullets to get the remaining lube out of places it shouldn't be.

Sprue lube conditions the mating surfaces of the metal really well, and prevents this type of problem most of the time.


Depending on how it got there, this can be traced to one of a few problems, these two being the most common( other than an unlubed sprue-cutter) :

A. Opening the sprue too fast; you are essentially dragging semi-solid hot lead between the surfaces. Bad ! Builds up fast, and will ruin either the sprue cutter or the mould in short order. Having done both, don't do this. 100% preventable.

B. Uneven plate alignment; Not all metal is as flat as it looks- especially when it comes to gaps the size of the vent lines on your mould halves. Can be either uneven to begin with, or can be created by over torqueing the sprue plate bolt, or- BOTH. Ya, that one is irritating.....Been there, too. I learn the hard way on most everything. This can be easily checked by "smoking" the top of the mould blocks with the sprue cutter away from the blocks, closing the sprue and opening it. You will get different "readings" in the soot depending on using a hot vs cold mould, but it'll give you the story either way. Should be a clean slate all the way across the top of the mould blocks. If you get any large trails that look like railroad tracks, you have warpage. The cure for this one is a little intense. If its a lee aluminum mould- just deal with it. If its a quality steel/iron mould, or a one-off custom, any decent mould maker should be able to re-true either the mould blocks or install a new sprue plate thats true depending on where the problem is. You can re-true lee moulds, its just not worth it. I've done it using a diamond hone. 3 days later when it was done, I vowed never to do it again.

This covers about 99% of the issues. The rest are exceedingly rare, and not really worth discussing on what I assume is a new mould.

As to your "hazy" bullets :

Could be impurities, or a temp issue. Would need to see it. Given that its sounds like you are re-smelting in your casting pot, I'll lean towards impurities until the pics tell a dfferent story. Usually what happens is that you get a tiny dot of impurity, and it causes rapid oxidization as the alloy cools. If you examine the bullets AND the top of your lead pot when it cools, are the hazy spots about the same color as that hazy looking stuff around the edge of your alloy still in the pot ? if so, thats oxidization. Harmless. Irritating I know, for us perfectionists, but harmless. Given that I tumble my loaded ammo, the cast bullets never stay that shiny anyway. Its like caring that you ripped the wrapping paper wrong on your Christmas gift.

Sometimes those impurities can cause oxidization in our cavities- although it is rare. If you get the same "spot" over and over across multiple bullets, might be worth having a look inside the cavity casting the bullet, and giving it a clean-out using q-tips and lube. They dry it out using q-tips, and cast till they come out good.


Hope this helps !