Fluxing and casting questions

[dddddmorgan]

After spending a good bit of time reading and re-reading the fantastic work by Glen Fryxell and Robert Applegate (From Ingot to Target) I've come to realize how much I didn't know about boolit casting! I love to learn so this is a good thing.

With my indulgence of a new Lyman Mag 25 furnace I've been happily casting the best boolits of my life over the last few days. In fact I reached into the ammo can last night to refill the furnace and realized I'll have to make a trip to the storage unit to resupply; I probably had 100 lbs in the can so I've been having fun

On to my questions: When casting do you put the sprue back into the pot? I've been doing this since the Lyman furnace is so nice and powerful and that thermostat is accurate so I can keep an eye on when I'm cooling the mix too much.

If you do put cat litter on the top for insulation do you remove it periodically to flux? Do you flux halfway through a pot?

Looking forward to the input.

[Sasquatch-1]

I knock my sprues into an old loaf pan. When I get 20 or 30 in the pan I dump them back into the pot along with any reject I have.

[243winxb]

Sprues go into a metal pan, till there are 5 or so, 4 cavity mold, then dump into Lee 10 lb pot. Flux is beeswax bullet lube. No crap floating on top.

[Froogal]

Sprues go into a metal pan, till there are 5 or so, 4 cavity mold, then dump into Lee 10 lb pot. Flux is beeswax bullet lube. No crap floating on top.

That is pretty much how I do it except I use candle wax (small pieces) and I flux pretty much every time I add a significant amount of lead to the pot.

[jsizemore]

I drop the sprues in as I go. PID temp readout shows a dip of 8-10degF. I reduce the oxides at the start only with some wax I inherited from an old caster. I think it's candle wax mixed with paraffin cast in a cornstick mold.

[Mk42gunner]

I normally cut the sprue by twisting the sprue plate with a gloved hand. Most times the sprue lands in my palm, so it goes right back into the pot. Six cavity Lee molds are a bit different, those I typically drop in two or three at a time. They are still hot, so the pot temp doesn't fluctuate as much as if they had cooled to room temp.

Robert

[Winger Ed.]

I also cut the sprue, catch it in a heavily gloved hand, and slip/ease it back into the pot a couple seconds later.
Nothing special about it, it's just my habit and routine.

[Chill Wills]

I also cut the sprue, catch it in a heavily gloved hand, and slip/ease it back into the pot a couple seconds later.
Nothing special about it, it's just my habit and routine.

That is exactly what I do too. They are going back in hot and in a rhythm. Doesn't hurt a thing.

I don't flux, just skim off at the start of the casting session (and I don't heat cycle molds ether - for what that is worth). The alloy is a solution, not a mechanical mix. Yes, I loose a little metal but not the metal ratio.
I scoot all the oxides floating on top to the side of the pot and use the backside of the spoon to squeeze out the liquid alloy and up and out comes the tiny bit of oxides stuck to the backside of the spoon. I don't loose much! I put it in an old bread loaf pan, and after a year or two's worth I melt it and flux it then. I have had this analyzed. My shooting pard's brother worked at Cummins Diesel and did this for us.
At casting temperatures, 700 - 775F, Tin and Lead oxidize at close to the same rate and Antimony almost not at all. The melting point of Sb is higher than the other two and it appears it won't be a problem until the heat goes much higher.

[Bazoo]

I flux with beeswax, it makes the lead flow better than either sawdust of paraffin wax. I open my sprue with a stick, over a round cake pan. The sprue goes into the pan, and if the bullets have rounded bases, they do too. I have tried both ways, putting the sprues back, and holding off until the pot gets low. Most of the time I find myself after half a dozen casts or so putting the sprues back. I don't really see a benefit either way.

I do not flux normally when putting sprues back. If I have a batch of alloy that seems to need to be fluxed after adding the sprues, I'll hold off as long as I can on it so I can concentrate on casting.

[pworley1]

I usually cast with 2 molds at a time to keep the mold from over heating and to give the sprue time to cool enough not to smear the top of the mold. I fill the mold and set it down, cut the sprue off the other and dump the bullets, put the sprue back in the pot and repeat. The process takes longer to read than it does to do. I flux every time I add more ingots to the pot.

[littlejack]

I drop my sprues back in as I'm waiting for the puddle to solidify on my previous pour. Never had a problem. I flux good at the start. Sawdust and lube. I flux again when the alloy drops about 1/4 pot. Then repeat. I don't think there is a wrong way with all of the suggestions above.

[Slugster]

I have dropped the sprues right back into the pot and have waited until I have a pile of them. The only advantage of one method over the other is that when I drop the sprues into the pot as I cast, the pot keeps more pressure (I have a Drippy Richard - don't judge me) from the weight of the lead for a longer period of time. Results in better weights, less variation. Flux well at the beginning of casting session and whenever I reload the pot.

[Minerat]

If I ust the bottom pour, I cut mine into a loaf pan until it is time to refill the pot. Then dump back in the sprues and add more bars. Then go in and get some ice tea and relax until the PID shows the pot is ready to resume.

If I'm ladle casting then I just cut back into the pot.

[popper]

Sprue goes into old pan. After a lot of casting pot is half empty, sprues go in and I rest. Then stir and re-flux with BW. Any oxide on sprue will sink to bottom and NOT float to top without stirring.

[405grain]

Same as popper: Sprue's go into an old pan and get dumped back in the pot when the pan gets full. I stir in beeswax to flux the pot after the sprue's have melted, scraping the sides and bottom of the pot to get any crud to float, and skim off any impurities that rise up to the top. I figure (could be wrong about this) that if I dump the sprue in one at a time as I'm casting they might be getting air in to the mix that can oxidize the alloy. Probably not true, but we all have our own ways of doing stuff. I use a pair of thick welding gloves and open the sprue plate by hand. I only use a stick to rap on the handle hinge if a bullet is stuck in the mold (which isn't often).

[LenH]

Casting with an 8 cavity mold gives a big sprue. I use a lead hammer to open the
Sprue plate and then return the sprue back into the melt. I us e an old pro melt and those big molds are pot drainers for sure.

[Petander]

Old Pro Melt here.

Welder's gloves, sprue goes back right away to keep the pot from emptying too fast. Seems to work and the pace is good for bigger 4-6 -bullet molds. In summer I may use 2 to 3 molds,alternating. Hot plate,too. I only flux in the beginning of the session with beeswax. My alloy is clean to begin with.