New to casting couple of questions?

[muzzy17is]

What are you guys using for your tin when casting boolits and also what is the best stuff to use for fluxing lead when making ingots?

[shadowcaster]

You can use pure tin from Rotometals, rolls of solder, and pewter. All are good sources of tin. As for fluxing your melt... Use dry sawdust. You will see many claim that they flux with wax or oil. Waxes and oils are reducers, NOT flux. They help return the tin and antimony oxides back to the melt. Sawdust does both fluxing and reducing.

Shad

[bangerjim]

If you want to step into a big stupid argument, check this out:

http://castboolits.gunloads.com/showthread.php?212865-Who-else-just-fluxes-with-wax

Tin is expensive. Best to buy alloys that already have it in them rather than building up your own mix from soft lead. Clip-on wheel weights (if you can still find them), pewter as mentioned is almost pure tin, and solder from Home Despot (is actually lists the ratio of tin to lead).

Also check out the many private people on here that sell alloys! Good people!

http://castboolits.gunloads.com/showthread.php?209409-Lead-Wheel-weight-lead-Soft-lead-Alloy-lead-Custom-alloying-now-available!&highlight=phoenix

Use the search engine on here for your questions and you will find a plethora of information on just about anything you are wondering and wandering about.

bangerjim

[500MAG]

I use pewter that I get in thrift stores. I flux with sawdust.

[Le Loup Solitaire]

For casting bullets you don't need a lot of tin...1-2% is sufficient to make sharply filled out bullets. A common source of tin is in what is commonly referred to as "solder". It is readily available in hardware stores, home improvement outlets, etc., in rolls or in bars that are usually 60% lead/40%tin by composition. Again you don't need much of it to get some of the tin into the melt. Some folks are very careful about calculating and weighing pure tin, solder or other sources. You can do that if you believe that you have to for whatever reason you deem necessary. Keep in mind that tin is rather expensive so calculate what your needs are. As for fluxing (agents) do some reading on the subject. LLS

[lwknight]

You can use pure tin from Rotometals, rolls of solder, and pewter. All are good sources of tin. As for fluxing your melt... Use dry sawdust. You will see many claim that they flux with wax or oil. Waxes and oils are reducers, NOT flux. They help return the tin and antimony oxides back to the melt. Sawdust does both fluxing and reducing.

Shad

Sounds like you are saying that wax just don't get the job done!
I will disagree emphatically!!
First of all , we do not need "flux" as the true meaning is "flow" . Flux will help intermetallic bonding process like soldering. Serves no purpose in casting or " smelting " which in our world is simply refining junk alloy to clean ingots for later use.

So we get a pot full of junk lead , wheel weights , and whatever. Melt it down. There are a lot of oxides and other floaty impurities. Burning wax will break the surface tension and allow all the junk to float out cleanly with no alloy clinging on causing waste of good alloy. And it can reduce a goodly amount of oxides back into solution.

As for clean alloy, there will always be oxides. Even linotype has oxides when melted. You can reduce 99% of all oxides back to where you have only a tiny bit of carbon left using only wax.

To each his own but don't mislead readers to thinking that wax does not get the job done if you know what you are doing with it.

One other thought: Using wood chips also introduces calcium into your alloy which seems not to matter enough for anyone to notice a difference anyway.

[shadowcaster]

lwknight...
Sounds like you are saying that wax just don't get the job done!
I will disagree emphatically!!

I never said that wax will not do it's job. The point is, which job it does.

First of all , we do not need "flux" as the true meaning is "flow" . Flux will help intermetallic bonding process like soldering. Serves no purpose in casting or " smelting " which in our world is simply refining junk alloy to clean ingots for later use.

To quote gearnasher from another thread (http://castboolits.gunloads.com/showthread.php?184987-Fluxing-with-sawdust-tell-me-how/page2&highlight=sawdust)... "I also see that you don't understand what "fluxing" really is from a metallurgy standpoint. Most of what you call fluxing is really cleaning non-metallic dirt and minerals out of the melt by physical agitation". It actually does serve a purpose in smelting and casting.

So we get a pot full of junk lead , wheel weights , and whatever. Melt it down. There are a lot of oxides and other floaty impurities. Burning wax will break the surface tension and allow all the junk to float out cleanly with no alloy clinging on causing waste of good alloy. And it can reduce a goodly amount of oxides back into solution.

Again to quote gearnasher from another thread (http://castboolits.gunloads.com/showthread.php?212084-Flux-question&highlight=sawdust)... "Boolit casters typically use dirty, contaminated scrap from whatever source we can scrounge up, and that sort of stuff needs special attention to make the best boolits. Clean alloy like nuclear medicine shields or foundry alloy doesn't require as much cleaning.

We need to do three things to our alloy: Clean, reduce oxides, and flux.

Cleaning is accomplished by mechanical action, stirring and skimming dirt, sand, steel clips, rust flakes, copper jackets, whatever. A slotted spoon is adequate.

Oxide reduction is next. We need to deal with the oxide dross formation on top of the metal, whether in smelting pot, or a freshly-melted casting pot full of clean ingots. Boolit alloy dross is very rich in valuable tin, so we need to turn it back into useable metal rather than skim and toss it. The opposite of oxidation is a chemical process called "reduction", so if we induce a reduction/oxidation reaction on top of the metal, we can save the scum. Combustion is a redox reaction. Anything that will burn will trade electrons with the oxidized metal, sort of "stealing" the oxygen and freeing the tin and other metals from the scum so they go back into the alloy. Grease, wax, oil, sawdust, anything like that will work to reduce oxides, and if your alloy is clean of other contaminating metals waxes work fine for this job.

Now, about Fluxing. This is the part that seems to confuse everyone. If your alloy came from wheel weights or other dirty scrap, it likely contains a bunch of other metals that don't cast very well and mess up the flow, or FLUX, of the alloy. This makes it tough to cast good boolits. Things we want to get rid of are zinc, aluminum, iron, calcium, and a few others. Since what we want to get rid of is all pretty much more difficult to reduce than lead, tin, and antimony, we can remove it through adsorption. With a "d". Things that work really well at removing the oxides of contaminating metals are molten borate glass and the carbohydrates in wood. Wax won't do it. The problem with borates (such as Marvellux) is that they don't reduce any of the oxides at all, including tin, they just adsorb them and remove them from the alloy. If you want to save your tin/antimony/bismuth/lead oxides, use sawdust because it saves the good stuff and adsorbs the bad stuff so it can be skimmed and thrown away with the ash when it has finished burning.

So again, sawdust, being a hydrocarbon, will also reduce tin/lead/antimony oxides we want to save while adsorbing the remainder of the junk we want to remove and capturing it in the ash. Two for one, so to speak. Resiny, pine sawdust, particularly sappy yellow pine, is one of the best reducant/fluxes I have ever used because the resin is such a fine and quick sacrificial reducant, quickly reducing the good stuff so it won't get adsorbed, but leaving the oxidized trash metals for the carbon to soak up as the wood chars.

Sawdust and ash cannot get below the surface of the melt and cause problems unless you drag it down there physically so that it gets trapped below the surface tension of the alloy at the bottom of the pot. Carrying ash down there on the end of a fresh ingot, a handful of sprues, or by scratching around on the bottom of the pot with a wooden stick are the principle ways of getting ash junk on the bottom where it will migrate to the spout and cause inclusions in the boolits. Use common sense and it won't happen. A wood stick is the bee's knees for scraping all the stuck, baked dross off the sides of the casting pot, it reduces oxides on contact.

Gear"

In addition btroj and cbrick have this to say (http://castboolits.gunloads.com/showthread.php?204806-Flux-or-reducer)...

"btroj... An organic that burns inefficiently produces carbon monoxide. That gas is the primary reducing agent. It reduces, takes oxygen from, the oxides on the surface of the melt. This puts the tin and antimony oxides back into the melt, a good thing.
The "flux" part comes form substances like charred wood that can the bind, or adsorb, the impurities we want to remove. Some of these are other metals that are not desirable and some are things like sand, dirt, and other grunge.

It is a two act play. Reduction is act one. Anything that can burns can work. Act two requires something with a far bit of surface area or some other way of removing "stuff".

Marvelux does an awesome job of removing stuff but it doesn't reduce anything so it also removes the tin and antimony oxides from the surface, over time this can lead to reductions in the overall alloy quality.

cbrick... "Wax and/or oils will reduce the tin back into the melt.

The sawdust you have been using will do both, reduce the tin & antimony back into the melt AND remove impurities. Stay with the sawdust and you'll be good, leave the wax for those that believe they are fluxing with wax and refuse to listen to the metallurgy of lead alloys . . . They are not fluxing.

Here is an excellent description of the process in chapter 4.

From Ingot To Target (www.lasc.us/Fryxell_Book_textonly2.pdf)

Rick"

As for clean alloy, there will always be oxides. Even linotype has oxides when melted. You can reduce 99% of all oxides back to where you have only a tiny bit of carbon left using only wax.

You are correct in that wax serves it's purpose well as a reducer

To each his own but don't mislead readers to thinking that wax does not get the job done if you know what you are doing with it.

I did not mislead muzzy17is. His question was about tin sources and fluxing material. I gave him the best answer based on fact and my own experience. Had he asked about reducers, wax would have been at the top of my list as an answer. Is it not misleading to new casters to tell them that wax is a flux, when it is really just a reducer?

One other thought: Using wood chips also introduces calcium into your alloy which seems not to matter enough for anyone to notice a difference anyway.

Agreed.. proper fluxing removes the unwanteds anyway.

If using wax while smelting/casting floats your boat.. Then more power to you.

Shad

[el34]

Regarding tin sources, linotype has about 4% tin and a hardness of about 20-22BHN, and monotype has about 9-10% tin and a hardness around 30BHN. By mixing lino with soft lead 1/1 you come close to a good casting alloy with 2% tin and a hardness of around 12-13 give or take. Mixing lead/mono at 4/1 gives you 2% tin and a hardness around 7-8BHN. If your lead is harder than pure (5BHN), you'll get a correspondingly harder alloy. Clipon wheel weights are already pretty hard, so adding tin generally means pure tin or solder.

I've found that $18/lb virgin tin from Rotometals beats buying solder of any flavor at retail. But opportunities pop up, like finding pewter (pure tin) and solder in garage sales etc.

[evan price]

The tin is where you find it. Junk-store pewter. Solder in rolls or bar form from the scrap yards, garage sales, etc. Type metal where it can be found. Babbit metal, the same. SOme lead sources have tin, like Xray foil.
When I smelt I do it in 200# lots in a 3-gallon Stainless steel pot, and I use motor oil left over from changing the oil in my vehicles as flux. It's free, it's a great carbon source, and it works very well as long as the smoke is not a problem.
Stir with a 5-gallon paint stir stick, I get them for free from the home improvement stores.

There are two specific duties for flux, and they are needing different materials.
You have reducing fluxes, these remove oxygen from the melt surface and reduce oxides of tin or lead back into pure form because carbon is the '***** of the elemental world' and wants to bind with oxygen in any form. So the oxide bond with the metal is broken with heat, the oxygen recombines with the carbon in the flux, and you get pure metal and no oxides. This is where motor oil, sawdust, paraffin wax, etc. are good. Lots of free carbon, little to no expense to get it.

Then you have slag forming fluxes. These trap impurities and form a crust on top of the melt. The impurities and slag are skimmed off the surface of the melt. This is marvellux, borax, etc. for this type of flux. The steel foundries use limestone for this purpose to make slag. We don't get that hot!

Dirty used motor oil acts as a reducing flux, and it also containes additives that will allow it to form small quantities of slag (not much but a bit). The best used oil for fluxing is the oil I get from the Diesels, it is pitch black with all the trapped carbon soot.

Add a generous amount of flux material to the melt. I like to stack up the lead I want to melt in the pot, then pour motor oil over it to get it wet and oily (about a cup for a pot of lead). The oil will smoke off and then catch fire. This puts extra heat in the pot and gets the melt going faster, and starts the fluxing process.
Once everything is melted, stir the pot with your long wooden stick, scrape the sides and bottom to get the trapped crud to the surface, then flux it again. Pour more oil in, let it burn, stir some more, the let it burn out. Skim off the crust on top. Nice clean silver alloy is the result.

[el34]

Thanks Shad. Excellent post.

[shadowcaster]

Thanks Shad. Excellent post.

Sure.. No problem. I'm happy to help when I can, and keep and open mind so I can learn from others. :)

Shad

[js98367]

I took a gallon zip lock bag to the local Lowe's store and they were glad to give me a full bag of really nice sawdust for free. It smells great when I use it.

[500MAG]

I took a gallon zip lock bag to the local Lowe's store and they were glad to give me a full bag of really nice sawdust for free. It smells great when I use it.

I also like to stir it real good with a wooden spoon. I pick a pack of them at the dollar store. Talk about the smell. It smells like th fireplace.

[hawgfan]

I had my first problem with candle wax today, I don't know if I added to much or what but it would not burn off. I had to let the lead cool down and scrap off the wax just to get it out of the pot. I'm sure it was something I did wrong lol.

[el34]

Hawg, sometimes you have to light it with one of those long butane lighters. Don't be surprised when it goes "whuummp".

[500MAG]

I had my first problem with candle wax today, I don't know if I added to much or what but it would not burn off. I had to let the lead cool down and scrap off the wax just to get it out of the pot. I'm sure it was something I did wrong lol.
How hot was your melt?

[lwknight]

Wax will auto ignite at about 650 degrees or so when you start stirring.
Probably just not hot enough and you probably used too much.
A pecan sized chunk is a plenty for most pots.

Sometimes I light the smoke with a torch or match.

[bangerjim]

I took a gallon zip lock bag to the local Lowe's store and they were glad to give me a full bag of really nice sawdust for free. It smells great when I use it.

Be VERY careful using dust from Lowes and HomeDespot as they cut "other" wood products such as flake board, particle board, and pressure-treated lumber. All nasty stuff you do not want to use or breath the smoke from.

Use only virgin saw dust from a known source such as your own shop or a buddy that cuts pine, walnut, alder, oak ONLY. Or buy pet bedding at WalFart.

bangerjim

[bangerjim]

I had my first problem with candle wax today, I don't know if I added to much or what but it would not burn off. I had to let the lead cool down and scrap off the wax just to get it out of the pot. I'm sure it was something I did wrong lol.

Use ONLY a marble size piece of beeswax or a 1/8 slice of a tea light candle for your casting pot. Smelting is bigger so use more. If your wax catches on fire in your casting pot and you did NOT light it, you are too hot! Turn your temp down or you will never see the end of tin dross on the top!

Stir.......stir.......stir!

All the wax should be gone within a minute or so and only a black residue left on the top. If you are using a bottom pour, just leave it.

bangerjim

[hawgfan]

Use ONLY a marble size piece of beeswax or a 1/8 slice of a tea light candle for your casting pot. Smelting is bigger so use more. If your wax catches on fire in your casting pot and you did NOT light it, you are too hot! Turn your temp down or you will never see the end of tin dross on the top!

Stir.......stir.......stir!

All the wax should be gone within a minute or so and only a black residue left on the top. If you are using a bottom pour, just leave it.

bangerjim

I was using a big cast iron pot, I think I used 6 tea light candles. So I am sure I used way too much. I had to light it on fire with a match and it burned for a while but when it was done burning I caould still see wax on top of the lead. It was in liquid form and I couldn't spoon it out for nothing. Thanks for the help I will make sure I use alot less next time.

[bangerjim]

I use a 70# CI pot for smelting and use only ONE tea candle cut up into quarters. Stir....stir...stir the wax in. You should not have a thick layer of wax on the top!!!!!!!!! It may flame up, especially since you are probably using a flame to melt the soup.

But ease up on the wax! And you will be a happy melter!

bangerjim