Bottom Pour Furnace....Do You Need To Flux????

[rbertalotto]

With a bottom pour furnace, is fluxing necessary.

I buy my lead from RotoMetals so I know it is clean. When I flux I get a very little bit of discolored lead on the top. Can't I just leave it there as I'm drawing from the bottom of the pot.

Thanks!

[beagle]

I use two bottom pour pots (RCBS Pro Melts) and I always flux no matter what the metal source. No sense in taking a chance on anything in the melt and it don't cost anything. Besides, it also mixes the alloy present. Flux./beagle

[gray wolf]

If i know my metal is clean ( at least the best I can tell ) I still flux with a small amount of pine saw dust.
According to what I see I will treat the metal accordingly.
BUT I think it best to leave a cover of saw dust and or it's ash on top of the melt to keep tin from burning off.
Wax does not provide that feature . also wax is not a complete flux. So the answer for me is yes, since the saw dust is doing a double job, triple actually, it keeps the pot a lot cleaner.

[btroj]

The type of pot used has bearing on the cleanliness of the lead used.

I flux my RCBS every pot full.

[BruceB]

My ingots are cast from well-cleaned metal.

When I cast, the RCBS furnace is at MAXIMUM temperature (870* +/-) and I add hot ingots without fluxing and without stopping the casting routine.

It works for me, and bullet quality is fine.

[bangerjim]

I insure ALL my storage ingots are 110% pure by fluxing and reducing several times during the smelting process.

Therefore, I NEVER flux in my casting pots! Everything I know is ultra clean, so why introduce more crapola to it? What I do is use beeswax to reduce the tin back in. That you need/have to do. But fluxing a clean melt....................is a total waste of time and can even create more problems with crud in you spigot valve!

Now.....if you buy some unknown crapola from an unknown source (ebay, etc).....that is different. But Rotometals is reliably pure.

banger

[oldpapps]

I'm not a metallurgist.

My understanding is that 'fluxing' performs many functions.

When soldering, acid flux cleans the surfaces to be soldered, rosin promotes the solder adhering to the metals.

When cleaning liquid lead alloys, fluxing pulls/separates dross and dirt from the metal.

And the reason I flux. Although a pea-size lump of paraffin or beeswax, in itself does not mix or re-mix the metals component metals. It does allow the dross to be mixed into the body of the liquid metal with the effect of allowing the suspended oxides to melt and be re-incorporated in the mix. End results, I don't loose my tin to oxidation and removal as dross/scum. The hotter the pot, the faster tin separates.

I melted my first lead for casting back in 1968/9 and have used this process with, in my view, positive results. I may be all wrong, but that's what and why I do it.

Enjoy,

OSOK

[snuffy]

It does not matter where the alloy came from, or how clean you think it is. You still need to flux.

Lets get something straight, fluxing is for re-combining the alloy metals back to the metallic state. Any time you melt an alloy, you'll get oxides on the surface of the melt. It happens because there's air in contact with the surface. That causes oxidation. Since tin oxidizes at lower temps, it's more reactive with the oxygen in the atmosphere. So it oxidizes first.

The loss of the tin will gradually result in softer boolits, as the antimony needs tin to stay in solution.

A byproduct of fluxing is it helps float out grit and clean lead from jackets in range scrap. Yeah, I know you THINK all the sand is gone from your fluxing while smelting. Are you sure?

If your ingots have a dull gray look , then their surface is oxidized. Happens over time or if they got wet. Fluxing with sawdust will return most of that oxide back to the metallic state.

Sawdust is best for bottom pour pots, because you can leave the layer of ash to greatly slow down contact with the atmosphere. It's a complete fluxing agent as well.

[JonB_in_Glencoe]

With a bottom pour furnace, is fluxing necessary.

I buy my lead from RotoMetals so I know it is clean. When I flux I get a very little bit of discolored lead on the top. Can't I just leave it there as I'm drawing from the bottom of the pot.

Thanks!

I flux every pot full with saw dust using a charred oak stick to stir and scrape the sides, I use a stainless steel scraper on the bottom. I leave all the dross and ash on top of the melted alloy during casting. It helps insulate the melt for better heat control as well as minimizing oxidation.

[blikseme300]

If i know my metal is clean ( at least the best I can tell ) I still flux with a small amount of pine saw dust.
According to what I see I will treat the metal accordingly.
BUT I think it best to leave a cover of saw dust and or it's ash on top of the melt to keep tin from burning off.
Wax does not provide that feature . also wax is not a complete flux. So the answer for me is yes, since the saw dust is doing a double job, triple actually, it keeps the pot a lot cleaner.

This is what I do as well. I leave the layer of ash on top of the melt which prevents the surface from oxidizing. The sawdust when it has carbonized will reduce any oxidation as well as prevent further oxidation as the atmosphere is not in contact with the melt.

All cut sprues and ingots will have a layer of oxidation no matter how clean the alloy so a good stirring of the melt with sawdust will remove this due to reduction effect that the carbon creates.

I only use beeswax to clean range pickups and WW's prior to casting ingots. I use a separate bottom pour for this as I don't want to contaminate my casting units.

[imashooter2]

My ingots are cast from well-cleaned metal.

When I cast, the RCBS furnace is at MAXIMUM temperature (870* +/-) and I add hot ingots without fluxing and without stopping the casting routine.

It works for me, and bullet quality is fine.

I do the same, although the pot is a little cooler. Cleaning alloy? Sure. But I can't recall the last time I fluxed my casting pot.

[Bigslug]

I flux - with sawdust - only when smelting scrounged metal into ingots. For casting from a bottom pour pot, I'll float about a half inch layer of kitty litter on top to prevent oxidation of tin. When done casting, I skim that off, along with whatever crud might have been in the melt. Crud's gonna float to the top, your boolits are gonna come from the bottom. As long as your metal is decently clean going in, there's nothing to lose sleep over.

[Lloyd Smale]

I flux my bottom pour once at the start of a session. I use clean lead and even if i add lead as im going dont flux again.

[6bg6ga]

I flux everytime I fill the pot prior to casting. It doesn't take long and it assures the lead is cleaner.

[tengaugetx]

I also use a bottom pour Lee 4-20. No way am I going to introduce anything to the pot that could cause a bigger chance of contaminating my pour spout.
I flux my melt at least three times before I cast ingots. Some of the phone lead I get has alot of tape, sealant and who know what else in it, so I flux it more.
I am very confident my ingots are clean before they go in my casting pot. If there are any doubts about the cleanness of my alloy I take care of that before I cast it into ingots. If I bought alloy I was unsure about I would smelt it down, flux and recast into ingots.
I cast in the house so I do not want to flux or reduce my mix then. I get very little dross/crud on the top of my pot. I have found that I get less to almost no yellowing on the top of my mix from the tin separating if I cast at lower temps.

[trixter]

[QUOTE=JonB_in_Glencoe;2502590]I flux every pot full with saw dust using a charred oak stick to stir and scrape the sides, I use a stainless steel scraper on the bottom. I leave all the dross and ash on top of the melted alloy during casting. It helps insulate the melt for better heat control as well as minimizing oxidation.[/QUOTE

Yup, me too.

[Doc Highwall]

I have four of the LEE bottom pour pots and I flux with wood chips and stir with a metal spoon that has a radius that will get into the corners (make it before you fill the pot) and I also use a wood stick to stir with and I always leave the ashes on top.

[fredj338]

I only put clean alloy in my BP pots. I use a wooden paint stick to stir every so often. That is enough to keep things flowing well. I save the sawdust for smelting alloy.

[Calamity Jake]

For those gentelman that don't flux there bottom pour pot, empty it out some time and see how much dirt is in it.

I too flux my smelting pot 3-4 times before I pour inguts, but I still flux my 3 BP pots.

[ShooterAZ]

Even with clean lead from roto-metals, some alloys (especially #2) will be lumpy on top with tin & antimony. You still need to flux it to get it combined, no matter what!

[williamwaco]

Yes!!!

[Shiloh]

I do. Can't hurt.

It's how I learned. My ingots ar clean, but oxidize in storage.

Shiloh

[WALLNUTT]

Once antimony lead and tin combine it forms a true solution and cannot be seperated but will oxodize

[varmint243]

I don't flux when I smelt range lead or when I cast
I tried it a few times, I can't stand the smoke and stench
I just scrape the crud off as I go
I cast about 5,000 bullets last year and did not notice any problems
My friend tested my bullets with his hardness tester and they are about the same hardness as COWW
I am shooting 38 and 45ACP target loads chrongraphed between 700 - 800 fps
Harness, alloy, lube, whatever, doesn't seem to matter much at those speeds
I do notice the tin forming a layer on the top, If I was shooting rifle or magnum pistol loads it would concern me because it gets scraped off with the crud.
I don't see any specs or grit or any of the other things I have read about.
YMMV - who knows after another year of casting experience I may just be the biggest proponent of fluxing on the forum

[WALLNUTT]

If it floats I don't want in my alloy

[snuffy]

I don't flux when I smelt range lead or when I cast
I tried it a few times, I can't stand the smoke and stench
I just scrape the crud off as I go
I cast about 5,000 bullets last year and did not notice any problems
My friend tested my bullets with his hardness tester and they are about the same hardness as COWW
I am shooting 38 and 45ACP target loads chrongraphed between 700 - 800 fps
Harness, alloy, lube, whatever, doesn't seem to matter much at those speeds
I do notice the tin forming a layer on the top, If I was shooting rifle or magnum pistol loads it would concern me because it gets scraped off with the crud.
I don't see any specs or grit or any of the other things I have read about.
YMMV - who knows after another year of casting experience I may just be the biggest proponent of fluxing on the forum

Can I have the dross---scum---layer that you're scraping off the lead? It would be a great source of tin for my alloy.


If it floats I don't want in my alloy

What floats may BE some of your alloy. At least the tin part of it. I'll repeat my above comment, send me your dross!

[varmint243]

Can I have the dross---scum---layer that you're scraping off the lead? It would be a great source of tin for my alloy.



I honestly believe there is nothing salvageable in the crud that gets scraped off.
If there was I would be happy to send it to you.
99% dirt/dust 1% metallic crud mixed in.
If your still not convinced, I can send a pic and you can see for yourself that it's nothing you or anyone else would want.
I usually just take it back to the range and toss it on the backstop.

I consider myself quite fortunate to have a neighbor that takes the jacket material for me.
He is willing to clean it, sort it with a magnet, pull out any FMJs that didn't bust open and does who knows what with it. :roll:

[WALLNUTT]

WAS in my alloy

[captaint]

I use a bottom pour and I use sawdust always. First, I like the layer on top of my melt to help prevent oxidation. Even though my ingots are clean, I still get those little spots in my boolits - that tells me it's time for a stir. Then I take a spoon and smash the "stuff" against the side of the pot and it shrinks considerably. Now we've blended the metals together again and I pull the little bit of ashy stuff that's left. Keeps the boolits clean !! Mike

[terryt]

Hi:

A friend told that he has been using bullet lube the cheapest he can findfor over 40 years. Has any else heard of this?

thanks,

Terryt

[snuffy]

Hi:

A friend told that he has been using bullet lube the cheapest he can find for over 40 years. Has any else heard of this?

thanks,

Terryt
I assume you mean for flux??¿¿

Boolit lube can be made of many different oils and waxes. Both paraffin wax and beeswax. Some contain alox, a synthetic lubricant, others may have ATF in them.

They ALL would work good for fluxing, BUT not as good as sawdust.

[Doc Highwall]

Not to mention the saw dust and wood chips smell a whole lot better. I bought some cedar bedding real cheap at tractor supply and it makes it smell like I am not casting.

[Rooster59]

Thanks for having this conversation guys. I just learned a whole lot more about casting in the three minutes it took to read this than I have in two years of researching how to do it.

[myg30]

That's the best thing about this site, the information is great and reading everything you can is beneficial. Click on the cast bollit notes from L.A.S.C below and keep reading. SOOO much to learn and if your like me its a great reminder of what you forgot !

Saw dust on top of lee bottom pour pot always workd fer me. If im smelling the wood im breathing in lead and its a good reminder as well as doing its job of keeping the O2 from killing my mix.

Mike

[Nrut]

That's the best thing about this site, the information is great and reading everything you can is beneficial. Click on the cast bollit notes from L.A.S.C below and keep reading. SOOO much to learn and if your like me its a great reminder of what you forgot !

>>Saw dust on top of lee bottom pour pot always workd fer me. If im smelling the wood im breathing in lead and its a good reminder as well as doing its job of keeping the O2 from killing my mix.<<

Mike
>>This last statement does not make sense..<<

[myg30]

To keep it from oxidizing is what I ment.

Mike

[Ole]

With normal/clean ingots, I usually put some sawdust on top of the melt when I start casting.

I don't normally actually clean/flux/remove anything from the pot until the pot gets down to around 4-6-8lbs left.

[rbertalotto]

I'm the fellow that started the discussion............Amazing amount of knowledge on this site!


Can I have the dross---scum---layer that you're scraping off the lead? It would be a great source of tin for my alloy.

This is what I feared. I scrap off this "stuff" from the top of the melt and I was afraid it was the tin. I use a wood paint stirrer to "flux" as I was told as it chared in the lead it added the carbon or some such thing. Was I told correctly? Anyone else ever hear about using a wooden paint stirrer to flux?

I saved this "stuff" I scraped off. Should I introduce it back into the alloy? And then flux as recommended here...sawdust?

Thanks!

[bangerjim]

I honestly believe there is nothing salvageable in the crud that gets scraped off.
If there was I would be happy to send it to you.
99% dirt/dust 1% metallic crud mixed in.
If your still not convinced, I can send a pic and you can see for yourself that it's nothing you or anyone else would want.
I usually just take it back to the range and toss it on the backstop.

I consider myself quite fortunate to have a neighbor that takes the jacket material for me.
He is willing to clean it, sort it with a magnet, pull out any FMJs that didn't bust open and does who knows what with it. :roll:

I save all my skimmings and gunk in a can. Later when I have a 3# coffee can full, I remelt it with beeswax and alder saw dust, then skim off the dirt. I end up with a LOT of heavy tin-based ingots from that stuff that many seem throw away.

Put me on your list to get skimmings too!!!!!


banger

[Ghost101]

Ok, I started using wood shavings that you buy at the pet store. Yesterday all was very good an liked how the pot an lead was flowing. Didn't care for the smell that much thou. Today as I was adding more lead to the mix,I also added more of the wood chips, I stirred it up a bit, scraped the sides an bottom, when all of a sudden I hear a bubbling sound. I pulled the spoon out an a twinkle latter lead whoosed out of the pot. Not a whole lot, but enough to hurt you. I store my lead in ammo cans, .50 cal. And the wood chips are in a sealed plastic container.
What did I do wrong to get this to happen?
By the way, I like how the sides of the pot are so clean as it gets lower an lower.

Ghost101

[Shuz]

I flux with Marvelux at the beginning of my casting sessions with any new "clean" alloy in my bottom pour furnaces. I know a lotta the folks don't like Marvelux, but it has worked well for me down thru the years. After I flux and scrape any grit and grime off the top of the melt, I introduce a layer of new, not used, kitty litter to the top of the melt. This layer of diatimaceous (sp)earth keeps oxygen from reaching the melt and reduces the need for further fluxing until sprues or new ingots are added. Often this is about the time head pressure drops and I need to replenish the alloy.

[WALLNUTT]

Well there's at least one other person using your system Shuz except I've found I don't need to flux when adding fresh clean ingots. I add ingots as I cast to maintain head pressure.With that said though I am going to try the wood thing after reading some or all leave the ash on top as a oxygen barrier.

[LenH]

I finally tried the sawdust for a flux. My son keeps reptiles and he has a bag of aspen bedding. I filled 2 coffee cans with it and tried it last night.
I got the alloy melted and the mold heated. I grabbed a handful of the shavings and put it on top of the melt and stirred for several minutes and left
the char on top of the melt. I have never had a more successful casting session. I was using a H & G 4 cavity #50 mold. Out of the 500 bullets cast
I only had 10 or 12 rejects.

Like someone said earlier, you read enough on here to learn a life time. But this old dog learned a great lesson about using wood shavings. I just need
the nerve to stir with a paint stick and I'll complete the fluxing circle.