Fluxing?

[Lead Freak]

Since I've been casting bullets, for the past 30-40 years, I have always fluxed the lead as just about everyone else seems to. My older brother, 64 yrs young, tells me that it's uneccessary to flux the lead since this apparently isn't required when using solder pots while dipping electronic components. He retired from a large automotive wiring harness company and said that the pots were never fluxed. I tried to explain that the lighter metals will naturally rise to the top, and if the pot is skimmed prior to fluxing, you will be removing all but the lead. Comments?

[Moonman]

You flux the metal by folding the risen metal back towards the bottom to maintain your alloy mix, kinda like folding egg whites back into a batter.

[plainsman456]

The stuff they use to do the components is of a higher grade that what we normally get our hands on.
They use something like 95/5 without any lead.
It keeps the lead from rusting when the pot os on.

[stubshaft]

I remember going on a field trip to the local newspaper years ago when they still used linotype (had to be about 45 years ago). We toured the area where they prepped the metal and the person there said that they fluxed the alloy every time they melted it with two raw russett potatoes. For some reason that always stuck in my memory.

The point being that if they fluxed it and used the alloy daily then it was good enough for me.

[geargnasher]

First, most electrical solder that I'm familiar with for such machines is eutectic 63/37, which doesn't need "fluxing" because it has no impurities in it to begin with.

Second, lead/tin binary alloy, and lead/antimony/tin ternary alloys DO NOT gravity segregate. Tin oxidizes on the surface (if oxygen is allowed to get to it) more rapidly than the other metals as far as I've been able to determine, and thus some is removed from the melt through skimming of oxides, but I'm not sure if eutectic alloys oxidize in proportion or not.

Don't confuse "fluxing" with "reduction of oxides", two totally different operations with different processes to accomplish them.

There's a great article by Glen Fryxell that's easily accessed on the lasc dot us website called "the 'simple' act of fluxing" that explains all this very well, check it out.

Gear

[MBTcustom]

I second Geargnashers comment. I work in an earospace company and we use solder pots all over the place. In fact, when the solder arrives in bar form, I have to shear it into usable lengths. There are no impurities in it. It is 63%tin and 37% lead and thats it. Now, there are oxides that form on the surface of the liquid metal, but they are very slight and easily swept to the side of the pot if a mirror surface is needed. Another thing is that this alloy melts at a low temperature (less than 400 degrees) and being a eutectic alloy, it is either liquid or solid with no slushy stage in between. I believe that the lead content is the culprit for much of the oxidization that occurs in the pot, as well as the impurities that are present in solution. Solder usually has a lower lead content than most alloys that are commonly found. So if my theory is correct, then that accounts for the difference. Ether way, if you dont mind working around a pile of dookie in your pot as you are trying to cast perfect boolits, and are happy with the results, then by all means dispense with all this fluxing business.
However, if you decide that you like your silver stream to be...well...silver, then I must pass on that sawdust is the most amazing flux I have ever used. (and I have tried a lot of things)

[runfiverun]

pine resin is proba nix that the very best fluxing/reducing agent i have ever used.
it do smell like pine trees though.

[Lloyd Smale]

I flux multiple times when i smelt but very rarely when im casting.

[cbrick]

Folding it back in?
Rusting lead?

Sometimes I feel like a complete failure in my attempts at explaining this. Gentleman, please do yourselves a huge favor and read chapter 4 from the following link.

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

Rick

[cajun shooter]

That is why I have used Pat Marlins wood flux for the past 4 years. It does the best job of fluxing and also acts as a cover of the alloy so that oxidation does not occur.
It is not saw dust like you get from table saw cuts but more of a shaving. It even smells good and that is from my SWMBO

[plainsman456]

When I said rusting I meant oxidizing.
I was in a hurry that day.
Every thing rusts in one way or another.

[Moonman]

+1+1+1 for Pat Marlins wood flux (California Flake Flux or CFF)

[fredj338]

Your bro ia probably tlaking about a soldering pot, & htey aren't trying to make perfect castings. A lot diff than sticking two wires into the lead to get a bond. FLux often, it can't be over done IMO.

[primersp]

+1 with runfiverun ,and i live near pines

[44 WCF]

When the lead and tin form an alloy, does it actually separate when heated like in our lead pots. For some reason I was thinking an alloy became a chemical compound aht won't separate like sugar in water, but am I wrong about that.

[cbrick]

When the lead and tin form an alloy, does it actually separate when heated like in our lead pots. For some reason I was thinking an alloy became a chemical compound aht won't separate like sugar in water, but am I wrong about that.

No, it does not, cannot seperate BUT what is in contact with the air, both on the surface of the pot and in the stream of alloy going into the mold does oxidize. In contact with oxygen = oxidation. Fluxing reduces (returns to the melt) oxidized tin and antimony, fluxing with the correct flux will also remove unwanted impurities such as aluminum.

Seperate . . . nope.

Rick

[hanleyfan]

One question, how do you ever get ahold of Pat? I been wanting to buy his wood flux and I have emailed him, PM him and posted on this web site and He never returns any of them, I wish he just let me know how to go about ordering some of His flux. On His web site he tells you contact through this site but I have no luck.

[geargnasher]

That's odd about Pat. I know he's going through some tough times right now, but as far as I know his business is full-steam ahead.

Gear

[SquirrelHollow]

So, if I want to keep oxidation to a minimum, I need to keep a layer of charcoal on the surface (when using sawdust), correct?

How, then, does some one ladle cast without getting charcoal all over the ladle?

I ask, because I can't figure out how to keep the charcoal or oxides out of my ladles (Lee, RCBS, Lyman, and a 1 lb Rowen). Everything I try to pour, while using sawdust as a flux, ends up with contaminants.

[cbrick]

So, if I want to keep oxidation to a minimum, I need to keep a layer of charcoal on the surface (when using sawdust), correct?

The easiest way to keep oxidation at a minimum is to keep the pot temp as low as praticle. The higher the pot temp the faster and more severe the oxidtion. Tin will oxidize first, lead last.

When I bottom pour (rarely anymore) I leave the burnt sawdust on top of the melt. When I ladle cast (most of the time) I remove it for casting. I give the alloy a quick stir with the ladle with each pour and this along with the pot temp at no more than 700 degrees helps keep any oxidation minimal.

Rick

[Bill*]

I remember going on a field trip to the local newspaper years ago when they still used linotype (had to be about 45 years ago). We toured the area where they prepped the metal and the person there said that they fluxed the alloy every time they melted it with two raw russett potatoes. For some reason that always stuck in my memory.

The point being that if they fluxed it and used the alloy daily then it was good enough for me.

Very interesting, but for some reason I keep seeing a "potato grenade" unless it was sliced thin and gently laid on the surface (maybe). I'd be too scared to try it though.

Never mind, I got it now (reread the quote in my post) :oops:

[SquirrelHollow]

Okay...
So, I changed my technique today, and managed to smelt 105 lbs of miscellaneous alloys, while maintaining a charcoal layer on the surface (until it was clearly saturated with oxidized metals). (8" dutch oven, running as much as 70 lbs of alloy at a time.)

While working with my single ingot mold (I really need 2-3 more), I was casting some Lee 429-200s and 429-310s for future alloy tweaking, and practice casting with the sawdust flux. I did finally find a technique that worked, and I feel like a bit of an idiot now. ;)


I do have to say, though... Today was the first time I stuck with sawdust-only for fluxing. I am absolutely sold.
I am using my own sawdust (Oak, Mahogany, Alder, Poplar, Pine, and Aspen), with about 10% crushed pine needles (my own, of course). I leave a 1/4" to 3/8" layer on the smelt, whenever possible, and ladle through an opening in the filth. It works extremely well.

But... Once I was done casting ingots of all the misc alloys, I had about 3 pounds of scrap, spillage, and leftovers from the various alloys (I kept them separate). Just to see what would happen, I added about 6 lbs of nasty dross from former smeltings that used other fluxes, and refluxed with sawdust. That 9 lbs of misc scrap turned into 8+ lbs of alloy, and just a little bit of dross.

Sawdust... awesome.:happy dance:

[41 mag fan]

I worked as a ast supervisor in a coil dept at a factory, before I switched careers. We soldered wire pins for welding leads on daily. We never fluxed the solder, which was a tin/lead mix. But we did flux the pins before dipping into the solder.
All we did was use a scraper to clean the pot to get the impurities to the surface

[cbrick]

Soldering is not bullet casting and using pure virgin solder shouldn't need fluxing. You did flux the wire for exactly the same reason we flux bullet alloy, to remove oxidation from the wire surface for a good solder joint. Or in bullet casting, a well filled out mold.

Rick

[PatMarlin]

One question, how do you ever get ahold of Pat? I been wanting to buy his wood flux and I have emailed him, PM him and posted on this web site and He never returns any of them, I wish he just let me know how to go about ordering some of His flux. On His web site he tells you contact through this site but I have no luck.

I don't know why we got a disconnect. Talk to folks every day.

Just email me:

mail (at) patmarlins.com

I try to get back within a day but sometimes I just to busy. I'll get back to you. I'm going to have a web site set up for easy ordering soon. And yes- I'm running full steam.

A word about CFF-

When I started selling it, boy did I catch a lot of flack. Folks over on another shooting forum went as far as calling me a crook, and my customers fools for buying such a thing.

What's funny about that is nobody has a problem with buying a favorite wood for their smoker, BBQ, or fireplace. No problem with a favorite species for your gunstock, or handgun grips, or your shop project. We could go on and on with that nonsense.

My CFF is all into it's own. You will not find that wood anywhere unless you live in these here forests that have the same trees I run on my mill. Why in the world does it work so well? I have no idea.

I go to a lot of work to plane, then mix (clean) shavings from 3-4 species of old growth trees from my property here. Mix it up and bag it, then of course box it and it's work. The post office is making the money on it, but I hate to waste such a fine resource and it puts a smile on guys faces, so I'll keep doing it.

Be careful burning pellet chips. Some use nasty stuff in them, and you never know what is in anything that doesn't come from a pure source. Same with just any sawdust. I do not sell sawdust.

CFF is pure as a product you can find anywhere and comes from my trees right here:

...:Fire:

http://www.patmarlins.com/oldgrowth.jpg