Fluxing?

[jsteed]

Haven't been able to locate much about fluxing and as I'm getting close to casting for the first time, I understand it is part of the procedure. On another site I see the use of sawdust, beeswax, parafin etc. How often is fluxing done during a casting session? Thanks for info.

[mdi]

I will flux as soon as the alloy melts and once or twice per potful (20 lbs. if I cast that long per session). I use sawdust and a pine stick (like a paint stir stick) and occasionally just stir well with the stick (I found some "shims" at my local hardware store/builders supply. They are cheap wood, about 12" long, 1 1/4" wide, and 1/4"-3/8" on one end, tapering to a point at the other. Pretty rough cut and works well for stirring my pot. Cost about 5$ for a bundle of mebbe 24).

[FLINTNFIRE]

If you are talking about smelting your lead , I flux it a couple of times while pouring ingots , after it is cleaned and in ingot form I start it melting in my pot and usually add the sawdust and add more sawdust after I have ran the pot down and added more metal , with me it is more of a how it looks and what I feel like

[dmclark523]

Good question. I also struggled with this at first, but it's relatively easy. After you get your pot filled and the alloy melts, throw in a handful of sawdust. It'll smoke pretty bad and likely won't smell good, but as it starts to turn black, stir in for about a minute. I use a cheap $1 serving spoon from the Dollar Store. Scrape down the sides, and scoop it out.
When I first started, I bought a jar of this: http://www.midwayusa.com/product/593033/frankford-arsenal-cleancast-lead-fluxing-compound-1-lb
It works great and doesn't really smoke or smell, but its a bugger to get out of the pot. I find that wax or anything like wax just makes a mess, so I generally stick with sawdust shavings. Good luck!

EDIT: I don't ever find the need to reflux during casting, but it might be a good idea to do so, and stir the pot up a bit.

[cbrick]

Here ya go, accurate full description of fluxing, what it is, what it does and why you do it.

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

I recommend the entire book but chapter 4 is on fluxing. It will explain why wax & oil are not fluxes and cannot flux.

Rick

[detox]

Ladle or Bottom pour?

Ladle: I flux more often using ladle because of excessive dross built up on surface and ladle. Before casting I first flux and clean metal using pine sawdust. I stir vigorously while scraping sides and bottom with stainless spoon. Then skim off dirt to get melt mirror clean. There after i use parafin or beeswax just to put dross back into the melt. I take a break about every 30 or 45 minutes then flux using wax before going back to work.

Bottom pour: I flux way less often using bottom pour. Too much fluxing will leave contaminants (ash, dross, sawdust residue) between melt and pot ...you will never get all out without draining and cleaning pot. These contaminants will eventually run down then out into bullets causing dirty bullets with small voids. I never stir using stick because the stick leaves contaminants between wall of melt and pot. I allways stir vigorously using stainless spoon.

I once tried sappy pine lighter sawdust for flux thinking it would work better. Wrong! This stuff leaves behind a nasty mess that is hard to clean off. Regular pine board sawdust works better for me.

[geargnasher]

Haven't been able to locate much about fluxing and as I'm getting close to casting for the first time, I understand it is part of the procedure. On another site I see the use of sawdust, beeswax, parafin etc. How often is fluxing done during a casting session? Thanks for info.

Do read the link CBRick posted, it is exactly what you're looking for.

Rick and I have made dozens upon dozens of lengthy posts here give our versions of the explanation, as well at a few tips. A brief site search using his or my handle and the keyword "sawdust" will yield a lot of excellent reading. One of the better recent threads was started by Murphy in the "lead and alloys" sub-forum, it's on the first or second page there, check it out too for some practical tips.

Gear

[sthwestvictoria]

I use sawdust when smelting as it seems to help loosen the steel clips from the WW. THis then gets scooped off with the clips and dross from the top of the smelt before it is poured into muffin ingots.

When casting boolits I don't really flux as all if it is a new ingot. If I am melting reclaimed boolits I do flux then, either with the dry sawdust again or just by stirring with a piece of pine or cedar board (bone dry). This is also good for making sure you are scraping the bottom of the pot (I ladle cast only from a cast iron pot)

[detox]

I use sawdust when smelting as it seems to help loosen the steel clips from the WW. THis then gets scooped off with the clips and dross from the top of the smelt before it is poured into muffin ingots.

When casting boolits I don't really flux as all if it is a new ingot. If I am melting reclaimed boolits I do flux then, either with the dry sawdust again or just by stirring with a piece of pine or cedar board (bone dry). This is also good for making sure you are scraping the bottom of the pot (I ladle cast only from a cast iron pot)

Next time i use my RCBS bottom pour pot i will try not fluxing. The pot has been emptied, cleaned, and is now ready like new.

[runfiverun]

I return oxides back into my pots about maybe every 4th-5th time I cast with it.
if I clean it up it just gets oxidized again so I just leave it.
I will scrape the pot's bottom and sides every time I get it up to melt temp though.

[Gtek]

Bought two of those big stainless spoons with holes. First bent one with perfect angle for skimmimg and lifting, ground second one to match radius in bottom and flat sides to fit pot. One for this and one for that. Gtek

[CobraMan]

MARVELOX, use 1 teaspoon per 10 lbs of lead, scoop out the junk, then before you pour do it again, works for me. This is my procedure using wheel weights:
1. Melt down the ww's.
2. Scoop out the junk, clips, scum on top etc.
3. Flux with Marvelox, 1 teaspoon/10 lbs of lead. The Marvelox is a white powder when you put it in your hot lead, stir it around approx. 1 minute, it will turn black and kind of glob together, scoop it out and throw away.
4. Preheat your mould.
4. While pre heating your mould, toss in another teaspoon of Marvelox and clean the lead a second time, Niiiiiiiiiiiiice clean lead, Pour perfect boolits.

[waksupi]

Most of us here are against the use of Marvelux. It will rust everything within twenty feet of your pot.

[cbrick]

Most of us here are against the use of Marvelux. It will rust everything within twenty feet of your pot.

Yes indeed it will but even that isn't the worst part using Marvacrap. 3-4 times a year draining the pot and spending an afternoon grinding the hardened glass out of the pot with a stiff wire wheel in a drill motor. For those that use the stuff when you grind it out of your pot be sure to wear a quality dust mask, the clouds of black dust are borate glass particles, lead, antimony, arsenic and everything else that's been in the pot.

Then there the problem that it is a true flux BUT it not only removes contaminates that you want removed, it also removes tin, arsenic, antimony that you want in the alloy.

Then there is the problem of the tinsel fairy, it is extremely hydroscopic meaning it sucks up water better than a sponge. Have some of it dried on your casting tools and drop it into the melt and pray your fast enough to get out of the way. For those that use the stuff more power to ya, as for me I won't even allow the horrid stuff on my property much less in my shop. Would be a heck of a fight if anyone ever tried to put it my casting pot.

Rick

[detox]

MARVELOX, use 1 teaspoon per 10 lbs of lead, scoop out the junk, then before you pour do it again, works for me. This is my procedure using wheel weights:
1. Melt down the ww's.
2. Scoop out the junk, clips, scum on top etc.
3. Flux with Marvelox, 1 teaspoon/10 lbs of lead. The Marvelox is a white powder when you put it in your hot lead, stir it around approx. 1 minute, it will turn black and kind of glob together, scoop it out and throw away.
4. Preheat your mould.
4. While pre heating your mould, toss in another teaspoon of Marvelox and clean the lead a second time, Niiiiiiiiiiiiice clean lead, Pour perfect boolits.

I agree. I have cast LOTS of verygood boolits using Marvelux or parafin. My 20 year old Lee pot and Lyman ladle are not rusty...***

Allthough sawdust or parafin cleans up lots easier than Marvelux.

[454PB]

Me too. I've been using Marvelux for over 30 years, none of my 35 year old pots are rusted, no tinsel fairies, and boolits look and perform just fine. Anytime you drop a cold dipper or stirrer into molten lead, you're asking for trouble. I simply preheat my dipper (if I'm not using a bottom draw) or stirring/fluxing spoon.

I once left a pot full of alloy heating for 48 continuous hours, fluxing with Marvelux every 16 hours or so, and never did produce pure lead....only lots of dross.

[cbrick]

I once left a pot full of alloy heating for 48 continuous hours, fluxing with Marvelux every 16 hours or so, and never did produce pure lead

Of course not, why would you think you would?


....only lots of dross.

True, dross containing your tin & antimony.

The answer here is really very simple, if your happy with the stuff you should by all means continue to use it. I used it for many years exclusively but I learned and never looked back. I would quit casting before I would put the stuff in my pot again.

Rick

[454PB]

We're told that Sn & Sb oxidize out of the alloy, and I know they do, but if 48 hours in a molten state doesn't remove them to where all that's left is pure lead, how much is lost in a 2 to 3 hour casting session?

Yes, we'll agree to disagree, but it bothers me to see misinformation such as pots rusting out and lead explosions blamed on the users failure to follow basic safety practices.

[cbrick]

if 48 hours in a molten state doesn't remove them to where all that's left is pure lead, how much is lost in a 2 to 3 hour casting session?

It is physically impossible for all practical purposes. But each time you remove what you are calling slag you are depleting the alloy. Perhaps with enough time and enough fluxing's you could get to near straight lead, how long? Dunno, hundreds of fluxing? What you are removing is what was at the surface of the melt and oxidized, the rest will not separate.


it bothers me to see misinformation such as pots rusting out and lead explosions blamed on the users failure to follow basic safety practices.

No misinformation, the stuff is highly hydroscopic. It holds water better than a sponge, the stuff absolutely does coat everything with a hard molten borate glass that is very difficult to remove. Inadvertently drop a spoon into the pot and watch the show, no misinformation there. Years ago when I used Marvacrap what I scooped off the melt I placed in a metal coffee can (remember those :mrgreen:) and the only thing in my shop that rusted was the can with Marvacrap in it and the bottom rusted completely off.

I posted no misinformation, everything I said is true and based on studying the stuff and my experience using it for years. I am very careful about posting what I know to be true and not pass on old wives tails, rather upsetting to be accused of spreading misinformation. I did not!

Once again, I am not trying to tell you or anyone else not to use it. If you like it use it it's no skin off my hieny but there no doubt are others reading the posts willing to learn something.

Rick

[detox]

No misinformation, the stuff absolutely does coat everything with a hard molten borate glass that is very difficult to remove.
Rick

Marvelux is water soluable and cleans up easily with hot soapy water.

No rust here, but i bring all my casting equipment back in the house after use

[Smitty's Retired]

Sawdust, it's cheap, it works the best for me, and if you read what fluxing is supposed to accomplish, wood seems to be the best choice in my opinion.

[jsteed]

Thanks for the feedback guys. Didn't have any intensions of starting a debate, but as I have an unlimited supply of saw dust and shavings, I guess I'll use what I have.

[khmer6]

I'm about to do my first batch of wheel weights. Where do you get swa dust from.... I know the simple answer might be cutting up some 2x4 but is there other sources

[blackthorn]

Take a box/bag down to your local building supply store and ask. You may also find a woodworking shop close by that will be glad to give you a box/bag full.

[303Guy]

I tried a new to trick yesterday. I have a fiber cover I place over the melt in the pot and this time a placed a piece of wood on the melt under the cover. That produced smoke which deposited onto a cold mold like tar (I quickly removed and cleaned the mold). Anyway, this time there was no dross formed on the melt. I did not actually flux as the pot was fresh and clean. One day I'll set up a small gas flame over the melt to expel air and maintain a reducing atmosphere.

[geargnasher]

When I built my new gun room, I was going to build a casting cabinet that had a shutoff on the vent and regulated CO2 being pumped in so I could do all my casting in an oxygen-free environment. I even ran a gas line through the wall. My concern, and why I didn't follow through with the idea, is that heat would quickly build in a 2x3x3' space with no ventilation and a 700-degree pot of alloy going on. That and long sessions working through the barrier gloves would be a pain.

Gear

[CobraMan]

Me too. I've been using Marvelux for over 30 years, none of my 35 year old pots are rusted, no tinsel fairies, and boolits look and perform just fine. Anytime you drop a cold dipper or stirrer into molten lead, you're asking for trouble. I simply preheat my dipper (if I'm not using a bottom draw) or stirring/fluxing spoon.

I once left a pot full of alloy heating for 48 continuous hours, fluxing with Marvelux every 16 hours or so, and never did produce pure lead....only lots of dross.

Thank You..........................................