Oatmeal on top of lead melt questions

[chutestrate]

After all the advice I received on my mold question I believe I need to address another issue that was pointed out to me. Oatmeal on the top of my lead. Chances are it's zinc, and doing multiple fluxing/smelting...whatever word you choose to call it, with sawdust will clean it up a lot.

I questioned if there was a way to minimize removing alloys I want. Did some reading, and came away with the sense that if I kept my casting temp around 700 Fahrenheit that the zinc would not melt into my alloy and be captured by sawdust fluxing.

Am I correct, or are there better materials and ways to do it.

I'm finding this all quite interesting, and enjoy learning the process.


Or....in the end if I'm getting good fillout with what I have leave it alone, and buy some good certified alloy for hunting applications. Naww, what's the fun in that.

Thank you all for your guidance.

[MBTcustom]

The oatmeal on top of your melt is most likely undissolved alloy. I've dealt with it myself, and XRF tested it for content and found it to be surprisingly close to the alloy it came from.

[454PB]

What Tim said. Crank up the heat and see if it melts in.

[bhn22]

Flux the pot again. Often times it ends up being dirt or some other trash that didn't flux out initially. I tend to use sawdust for initial fluxing, then something like paraffin for the final round. It just works better to me somehow. You can usually pick up childrens crayons at the Goodwill store for practically nothing. Old candles work fine too. You can ignite the fumes from the melted wax to keep the smoke down.

[largom]

As directed by others, turn your heat up a little. Hopefully you have a thermometer and are not going by the dial on your pot. When you flux cover the top of the melt with sawdust and then stir well.

Larry

[mdi]

Wow! Where was my head? I saw the thread title and thought you were fluxing with Oatmeal (ya know, like Quaker Oats). I just might try Oatmeal flux next time I do some casting just to see if it works. Prolly smell good too...:bigsmyl2:

[chutestrate]

Ok, I'm using a thermometer. I'll be making some sawdust this week, and trying the fluxing.

[454PB]

This is very common when melting linotype or other type metals. A lot of people skim it off as dross and waste valuable components.

[GabbyM]

Heat it up to 800 degrees then flux it with white lard. It will smoke and flame a lot.

My guess is your casting thermometer is off by about 50 degrees and you're running 650 degrees when it says 700.

[dkf]

I get a small bit of "oatmeal stuff" on top of the melt sometimes and it can be hard to get it to go back in. I figure it is some alloys that got separated from the heat cool cycles I put it through from several cast sessions. I have found candle wax as a flux mixes it in real quick for me. Paraffin canning wax did not do it but the candle wax sure did.

[trapper9260]

Wow! Where was my head? I saw the thread title and thought you were fluxing with Oatmeal (ya know, like Quaker Oats). I just might try Oatmeal flux next time I do some casting just to see if it works. Prolly smell good too...:bigsmyl2:

When I seen the post, I was thinking of the same thing also.Let us know if you do use and let us know how it work out.Make a different post on it.

[chutestrate]

I will. I have a few different suggestions to try. I'll definitely try the candle wax since I can get my hands on some of the stanky candles my wife insists on buying. I'll have sawdust to try a little later in the week.

I imagine that these methods make a bit of smoke?

[Deadpool]

I will. I have a few different suggestions to try. I'll definitely try the candle wax since I can get my hands on some of the stanky candles my wife insists on buying. I'll have sawdust to try a little later in the week.

I imagine that these methods make a bit of smoke?

Ashes from a wood stove or fireplace works just as well, and without any smoke. Throw on a healthy scoop, stir it, and pour ladles of your oatmeal through the ashes. When "flux" like sawdust burn, it's leaving behind carbon. It's the carbon that is used as flux. Ash is simply the end result.

If you still keep getting oatmeal after turning the pot up to 700F (can you measure the temperature?) then you could have zinc contamination. Alloy separation (losing antimony) may only happen at lower temperatures before the whole pot reaches liquidus.

If you do have zinc contamination, a very small amount can cause oatmeal, and it'll keep coming out. So PUT IT ALL BACK IN if you've been removing it, you're just wasting good alloy. A tiny amount can be a good thing but will ruin your boolit after a long aging period, anyway. It's been posted many times on here, clean up your zinc problems using copper sulfate. A tablespoon as "flux", let it turn white before stirring, then stir pour through it, don't remove any unless the white chunks won't go away anymore. You'll be replacing zinc with copper using this stuff, which is very good to have in your alloy.

Copper sulfate will react with zinc much faster than anything else you have in your melt, so ignore what people say about losing tin, it only slowly reacts with tin if there isn't any zinc left, and you'll have a very hard time getting 2% tin to become 1.9% tin with this method.

[dkf]

I will. I have a few different suggestions to try. I'll definitely try the candle wax since I can get my hands on some of the stanky candles my wife insists on buying. I'll have sawdust to try a little later in the week.

I imagine that these methods make a bit of smoke?

The candle wax smokes quite a bit. A match to make sure the wax on top lights off helps keep smoke down. Make sure to wear gloves while you stir in the wax.

[texassako]

Fluxing removes stuff, reducing converts oxides back into the useable components. A ball of wax, lit after it melts and stirred while flaming, will eliminate the oxygen and reduce the oxides for you. It may take a bit more heat than the usual casting temp.

[btroj]

Ashes from a wood stove or fireplace works just as well, and without any smoke. Throw on a healthy scoop, stir it, and pour ladles of your oatmeal through the ashes. When "flux" like sawdust burn, it's leaving behind carbon. It's the carbon that is used as flux. Ash is simply the end result.

If you still keep getting oatmeal after turning the pot up to 700F (can you measure the temperature?) then you could have zinc contamination. Alloy separation (losing antimony) may only happen at lower temperatures before the whole pot reaches liquidus.

If you do have zinc contamination, a very small amount can cause oatmeal, and it'll keep coming out. So PUT IT ALL BACK IN if you've been removing it, you're just wasting good alloy. A tiny amount can be a good thing but will ruin your boolit after a long aging period, anyway. It's been posted many times on here, clean up your zinc problems using copper sulfate. A tablespoon as "flux", let it turn white before stirring, then stir pour through it, don't remove any unless the white chunks won't go away anymore. You'll be replacing zinc with copper using this stuff, which is very good to have in your alloy.

Copper sulfate will react with zinc much faster than anything else you have in your melt, so ignore what people say about losing tin, it only slowly reacts with tin if there isn't any zinc left, and you'll have a very hard time getting 2% tin to become 1.9% tin with this method.

Ashes from a fireplace will not do anything. You need low order combustion. Ashes won't burn.

[GabbyM]

Ashes from a fireplace will not do anything. You need low order combustion. Ashes won't burn.

Low order combustion. Well the lard at 800 degrees I suggested will rise a flame about a foot above the pot. That's what I meant by smoke and flame a lot. Little bit past low order combustion I'd suspect. I like to toss in some wood chips first. To get a fire started so the grease fumes don't build up and flash off. Candles work well to. Fancy flux is bees wax blended with lard. Sometimes known as black powder bullet lube. If you don't have a decent vented hood it may be time to go outside.

[btroj]

By low order I mean smokey. Lots of carbon monoxide is produced, that is the primary reducing agent.

[leadman]

I use Marvelux on lead alloy like this. Works well. Also Zep Root Killer which is copper sulfate will work. Be sure to leave it on the top of the pot until it changes from blue to white or you may have a visit from an unpleasant fairy.

[44man]

Our metals will alloy in at 600* but zinc will float into oatmeal. If you flux you just alloy in the zinc. Raising heat and fluxing just puts the zinc in easier. If a bunch of stick on weights were used you will have zinc.
I use pure antimony to make a harder mix and it melts in and alloys just fine at 600*, never go higher. Just needs the proper flux.
Get your lead to 600* and skim the oatmeal off, save it to play with later by itself. I can't see losing any good stuff since the zinc is not in alloy with anything. As long as you have tin, the antimony will stay in solution at 600*, it will not float.
Tin helps prevent oxidation at 700 to 750* hotter can reduce that ability and needs more fluxing to keep it in solution.

[cs86]

Someone correct me if I'm wrong, but I remember reading that if you have some muriatic acid that it can indicate if you have zinc in the pot. The acid has a reaction to zinc and turns green and bubbles. You could dab a little on the alloy and see what happens. I put some on a zinc wheel weight to learn what the reaction would be and it did bubble, I thought turned green and stunk to high heaven. So do it outside, have good ventilation, and keep your face away from it. I don't know if it has any reaction to the other alloys that might be in the mix.

[reloader28]

This is very common when melting linotype or other type metals. A lot of people skim it off as dross and waste valuable components.



The crazy old coot that started me casting does this. No matter what I say or how many times I say it, he always skims the top of the pot til its shiny, and then fluxes.[smilie=b:[smilie=b:
Makes me sick to watch.

[44man]

The crazy old coot that started me casting does this. No matter what I say or how many times I say it, he always skims the top of the pot til its shiny, and then fluxes.[smilie=b:[smilie=b:
Makes me sick to watch.
Depends on temperature. Best to soak at 600* before turning up the heat. Remove what does not melt. It is best to cast at 700* to 750* max, not 650*. Pure will need up to 800*. Add tin and you can reduce the heat.

[Deadpool]

Ashes from a fireplace will not do anything. You need low order combustion. Ashes won't burn.

I guess I don't know how to flux then. I suppose that also means I never needed to flux, if my fluxing didn't do anything. And I thought my shiny, perfectly formed boolits with low tin were a direct result of my understanding. I guess I'm just perfectly stupid.

[Char-Gar]

Here is what I have been doing for many years;

1. Put alloy 1 lb ingots into the pot and bring to full temp. Allot of folks are impatient and do not wait long enough and try to cast with alloy that is not hot enough. Then end up turning the setting on the furnace back and forth, like they are trying to find a radio signal. They chase the temp up and down trying to find the right place, when waiting another 20 minutes would have made this unnecessary.

I have never owned a lead thermometer. I heat the alloy until it will flow through a dipper like water. Even though I use a bottom draw furnace, I check the alloy with a dipper to make sure it is hot enough. I note the setting on my furnace and seldom have to change that setting.

2. Flux well, stiring and scraping the sides and bottom of the pot to disloge any dirt.

3. Repeat No. 2 above.

4. Skim off and discard any dirt and impurities that have come to the surface. Anything left floating on full temp alloy after two good fluxes, is not anything you want in your bullet.

5. Cover the top of the melt with 1/2 inch of clay kitty litter.

6. Place other 1 lb ingots on the lip of the pot to warm.

7. Cast my bullets

8. With a pair of tongs place warm ingots on top of the kitty litter and let them sink when more alloy is needed. Depending on how much alloy there is left and how much you add you may need to let the alloy come back up to temp again. There is no need to reflux when adding alloy.

9. Replace the warm ingots with fresh ones on the lip of the pot.

10. Continue casting and repeating adding newly warmed ingots as needed.

11. When through, unplug pot and go have a beer.

[GabbyM]

44man:
If it is zinc. Zink will separate back out after turning the temp back down. Then you'll know. Sb will separate out. Especially when ladle dipping. Since I have CRS I'd need to get the book out again to see just why that is. Think it has some to do with the tin oxidizing.

An old saying. Use a big enough hammer and it will go in.

[Char-Gar]

I guess I don't know how to flux then. I suppose that also means I never needed to flux, if my fluxing didn't do anything. And I thought my shiny, perfectly formed boolits with low tin were a direct result of my understanding. I guess I'm just perfectly stupid.

I would not be so quick to take offense. There is not particular mystery to fluxing. I have used candle wax, paraffin, beeswax, bullet lube, motor oil, olive oil, saw dust and a few other things and they all work. I have never heard of folks trying to flux with wood ash, like like the other fellow I don't see how that would work. But, maybe it will. If you are happy, then no need to change or get miffed at folks who don't understand.

[MBTcustom]

I guess I don't know how to flux then. I suppose that also means I never needed to flux, if my fluxing didn't do anything. And I thought my shiny, perfectly formed boolits with low tin were a direct result of my understanding. I guess I'm just perfectly stupid.

Your not stupid. You simply did something you thought would work, and couldn't tell a difference between what you did, and the accepted forum wisdom.
Ive thrown just about any kind of stuff in my pot to "flux" that you can imagine. I am very disconnected with popular opinion and "solid facts" that are based on a measured effect that happened three conclusions ago.
IE:I really don't put much faith in statements that are three or four conclusions away from something I can observe, measure and test for myself.

When it comes to the subject of fluxing, the first thing I would ask is "what effect are you looking to achieve by doing this?"
For myself, I am looking for measured improvement in the quality, accuracy, and consistency of my bullets (see my thread "consiststancy applied" if you want to know what I mean by that.)

since my goals are clearly stated, I can see what produces a positive, neutral, or negative effect towards that end.
Now, you can operate how you wish, but for me, I don't care to do things that are neutral or negative, and I have a system to find out what is, and what is not.
I simply cast with and without said tool, and let the measurment tools and the appearance of the bullets decide if I get better results using said casting tool (sawdust in this case).

What I have seen is that sawdust is a two edged sword (like so many things). Yes, it does a good job of fluxing but does not aid castability of the alloy as much as beeswax does. Not only that, but there is a very real possibility of getting pieces of black dust in your bullets, which will cause your bell curves to go strange, which will prompt you to start filing through all of your bad bullets to determine what part of your process is messing you up, and when you find not voids, but little chunks of black stuff in your bullets, you might do as I have done and relegate the sawdust fluxing to the smelting pot only.

At the end of the day, all you can do is test the validity of your process for yourself, and once you know what works, when, where, why, and how much, nothing that is written on this forum is going to change that. It either works for you orit does not.
Actually, that's all were really here to find out isn't it? So if somebody tells you something does or does not work for you, you either know they are right or wrong, or you do not know whether they are right or wrong. I would indeavor to always be in the former state of mind via testing and experimentation, and when you are, people can say whatever they want, and claim whatever they want, to their hearts content, but the proof is in the pudding, and when the pudding tastes good, you don't have to share with those who don't like the taste.
LOL!

[44man]

Yes tin allows antimony to alloy so don't get metal too hot. Zinc is a funny metal and might surface as temps go down.

[JonB_in_Glencoe]

After all the advice I received on my mold question I believe I need to address another issue that was pointed out to me. Oatmeal on the top of my lead. Chances are it's zinc, and doing multiple fluxing/smelting...whatever word you choose to call it, with sawdust will clean it up a lot.

I questioned if there was a way to minimize removing alloys I want. Did some reading, and came away with the sense that if I kept my casting temp around 700 Fahrenheit that the zinc would not melt into my alloy and be captured by sawdust fluxing.

Am I correct, or are there better materials and ways to do it.

I'm finding this all quite interesting, and enjoy learning the process.


Or....in the end if I'm getting good fillout with what I have leave it alone, and buy some good certified alloy for hunting applications. Naww, what's the fun in that.

Thank you all for your guidance.

You never "clearly" stated if this Oatmeal was formed while Smelting raw wheel weights into Ingots, where you could have accidently melted a Zinc WW ?
OR
melting your ingots in your Alloy furnace for making boolits ?

If it's the Later, I'd say it's just Dross...like Goodsteel stated, that dross is gonna be the same as the alloy in your pot. You just need to reduce those oxides back into the melt.

NOW, if it's the Smelting of Raw WW, and this oatmeal is such, that no matter how much you skim off, more forms...then it's likely Zinc.
If you poured ingots, did they look like these ?
http://castboolits.gunloads.com/showthread.php?155778-my-first-Zinc-contamination-in-WW-smelting&highlight=

[chutestrate]

Sorry Bill, you are correct that I did not clearly state what part of the process I am in. I am melting ingots to make slugs. My ingots are very similar to the ones in your link.

[Springfield]

It has been stated here before by people who are smarter than me. Use some sawdust to bring all the impurities to the surface. It helps if the melt is at least 700, but not over 750, in my experience. Let it sit a while, at least 15 minutes. Then put some wax of some sort on top, stir it up and ignite it, making sure it covers the complete surface of the melt. The lack of oxygen will reduce the dross back into the melt. It may take 2-3 tries, but it almost always works, and I cast a lot. All you should have left on top is ash. Lots of times I thought I had zinc, but with following these steps it went back in 99% of the time. Just don't rush it.

[Cadillo]

When I began using monotype to sweeten my melt for good fill out, I at first had a problem with a lot of mush forming on top of the melt. The crayons and paraffin I was using at the time would do nothing to help with the issue. I then converted to using sawdust for flux, and through a bit of study, learned that the mush was mainly antimony, that requires that the melt be brought up to higher than casting temp in order to properly blend into the melt. That plus a good fluxing with sawdust does the trick for me.

As I ladle cast over a propane burner, I'm able to just lower my flame, and wait until the melt comes down to my regular casting temp.

[44man]

If you flux in any zinc and cast some boolits, you can get a galvanized rain gutter look to them. The zinc will move to the surface.
If you know there is no zinc and suspect just antimony, it will flux in at 600* too. Need some tin with it. Tin is the great binder and once alloyed in, antimony will not surface.
I have some pure lead that got contaminated, No stick on's in it, just cable sheathing and pipe. I don't know where zinc came from but I had galvanized boolits. At 600* I got it clean. Pure is very easy to clean.

[Engineer1911]

I had this problem when casting on my deck. The problem was 'low voltage' at my melting pot. After I built my garage, had a dedicated 'casting circuit', thoroughly cleaned the inside of my RCBS melting pot, it was the end of oatmeal on the melt.