Cover your furnace pot OR NOT?

[bbogue1]

Covering a pot makes it heat faster and reduces oxidation. I have a Lee Pro4 pot that I made a little cover for. Does anybody cover their pot while casting?

[OS OK]

No...I want to see when it's time to re-flux and stir in the oxidized surface. Sometimes you think you are running clean Pb and a thick layer of crud will surface...you want to get that stuff out of there.
Putting the sprue cuts or more ingots in the pot would prolly take something like pliers to remove the lid...a lid sounds like it might complicate matters a bit...

Often times, the colors will reveal a little something about the Pb you think you have...or the temp you think you are running unless you have a reliable thermometer or PID control.

Naw...I just like to see into the pot.

[ikarus1]

I cover it while its warming up with the same little SS dish that catches my sprues. Seems to help warm the pot and lead much faster

[Beagle333]

No. I like to see it and also I add sprues back as I cast, one my cadence is set.

[JBinMN]

Open tops on the 2 ladle pots & Lee bottom pour for me. I think I may pour too fast for the ladle ones to be able to do it & the bottom pour actuator would get in the way for that Lee one. Also, doing as OS OK said with the adding lead/sprues, fluxing, cleanout dross, etc.. I think it would be kind of a hassle with what I am using & how I do things.

[HATCH]

I don't cover mine up. I cast inside (have a vent).
If you cast outside and it is cooler then I can see covering the pot to keep the warmth in.

[OS OK]

Covering a pot makes it heat faster and reduces oxidation. I have a Lee Pro4 pot that I made a little cover for. Does anybody cover their pot while casting?

I noticed you made this statement in another thread this morning.
A lid on a pot will not reduce oxidation. The lid does not prevent oxygen from coming into contact with the surface of the Pb. Paraffin or bees wax or a thick layer of sawdust can do this though.
Sawdust is better because it can help remove impurities and reduce the tin at the surface back into the metallic state of the melt. You have to be careful with the saw dust as it can get down into the bottom valve and cause it to drip.
Paraffin or bees wax can form a barrier to the oxygen but doesn't pull impurities from the Pb.

Here's an interesting read that can explain this much better than I could hope to...http://www.lasc.us/Fryxell_Book_Chapter_4_Fluxing.htm

[John Boy]

Does anybody cover their pot while casting?

No - see no need

[country gent]

A flat aluminum cover with a small protrusion into the lead would act as a hot plate and warming spot for moulds and ingots to pre heat some also. It doesn't reduce or slow oxidation, On a 2 pot set up it may with a properly alighned hole reduce some splashing when emptying the top pot into the lower one though. I find a shield around the pots exterior speeds heat a lot more than just a cover.

[PaulG67]

No a cover just gets in the way.

[pjames32]

I cover while heating up, then remove to cast.

[Mike W1]

Mine were made with an insulated aluminum with a knob handle. Haven't bothered with em' for years.

[Walter Laich]

another chance for me to be odd man out

I bought the aftermarket one offered on this site as well as the shelf.

I think it keeps the pot at temp along with my PID. and as long as I 'think' it works, it does

gives me a place to put ingots to pre warm without an additional electricity usage

[Jack Stanley]

No , it seems to get up to heat just fine without it .

Jack

[Bzcraig]

No sir.....

[captain-03]

Nope!

[JohnH]

While I've never done this, making a manifold that would fit around or over the pot and running an inert gas like argon through it while casting would eliminate oxidation of the melt surface. The oxidation we observe comes from two sources, the melts contact with oxygen in the air and oxidized metal we introduce into the melt in the form of ingots or sprues. I don't put sprues or boolits directly into the pot for this reason. By weight, sprues have more oxidized surface than do ingots. Adding sprues not only adds more oxidized metal into the pot, they tend to splash and wave the surface exposing more of the melt to the air (oxygen) than adding ingots. Even using a bottom pour pot, adding sprues back to the pot creates the need to flux the melt more often. The only way to prevent oxidation is to remove or limit exposure to oxygen and the only way to do that is to displace the normal atmosphere, hence the use of a manifold for an inert gas. The rig wouldn't have to be sophisticated. One could rig a burner from an old gas stove to a supply line attached to a regulator on a bottle rented from a welding gas supply house. I've not done this as I really see no reason for this level of oxidation prevention. Using ingots instead of sprues to limit melt disruption, a bottom pour pot instead of ladling, keeping heat to 700 degrees or less if possible will all go to reducing oxidation. I typically run about 50 pounds of metal through my pot before I flux it and it is not uncommon to run twice that much. In winter I'm known to simply scoop the dregs off the top of the melt and toss it into the bucket I knock the sprues in and flux it all when I remelt the sprues and make ingots from them. I've said it many times, casting ain't rocket science, and it is actually quite forgiving, if it weren't lots of us here wouldn't be able to do it all

[JSnover]

If I need to add lead I'll cover it and take a break while the temp comes back up. Park the mold on top so it doesn't cool so much.

[JonB_in_Glencoe]

While I've never done this, making a manifold that would fit around or over the pot and running an inert gas like argon through it while casting would eliminate oxidation of the melt surface. The oxidation we observe comes from two sources, the melts contact with oxygen in the air and oxidized metal we introduce into the melt in the form of ingots or sprues. I don't put sprues or boolits directly into the pot for this reason. By weight, sprues have more oxidized surface than do ingots. Adding sprues not only adds more oxidized metal into the pot, they tend to splash and wave the surface exposing more of the melt to the air (oxygen) than adding ingots. Even using a bottom pour pot, adding sprues back to the pot creates the need to flux the melt more often. The only way to prevent oxidation is to remove or limit exposure to oxygen and the only way to do that is to displace the normal atmosphere, hence the use of a manifold for an inert gas. The rig wouldn't have to be sophisticated. One could rig a burner from an old gas stove to a supply line attached to a regulator on a bottle rented from a welding gas supply house. I've not done this as I really see no reason for this level of oxidation prevention. Using ingots instead of sprues to limit melt disruption, a bottom pour pot instead of ladling, keeping heat to 700 degrees or less if possible will all go to reducing oxidation. I typically run about 50 pounds of metal through my pot before I flux it and it is not uncommon to run twice that much. In winter I'm known to simply scoop the dregs off the top of the melt and toss it into the bucket I knock the sprues in and flux it all when I remelt the sprues and make ingots from them. I've said it many times, casting ain't rocket science, and it is actually quite forgiving, if it weren't lots of us here wouldn't be able to do it all

JohnH, I'm borrowing you post for an explanation/reasoning of my technique, as you have put it better than I could have.

I do not Ladle cast, I only do the bottom pour. I leave the dross (dregs) on top of the melt, if that layer is less than 1/2", I'll add some dross from a previous session. That dross will insulate it some, as well as block some O² to reduce oxidation, and also prevent splashing if I chose to drop the sprues back into the pot, which I do when casting pistol boolits.

[bbogue1]

This has been so informative. I do stand corrected. I have learned the only way to prevent oxidation is to eliminate oxygen from contacting the surface of the lead. The two thoughts that stand out to me is using the top surface of the molten lead to tell what is going on in the alloy by observing it's color and heat retention or increasing the initial melt speed is the real use of a cover with heating molds as an added bonus. Keep this up there are more ideas about a cover or not.