(Sawdust) fluxing with dip casting.

[huntinlever]

Just read the article by Glen E. Fryxell, "The Simple Act of Fluxing" on http://www.lasc.us/FryxellFluxing.htm. I've not cast in many years but am getting back in now and actually did use sawdust - my friend is a luthier so I always had plenty on hand. Though I started out with a smaller Lee bottom pour, I pretty quickly moved to dipping with a ladle and pot. As I recall, I would periodically re-flux and remove the floating particulate over the course of the smelting or casting session, though I don't recall any systematic approach.

I see the value of leaving the flux "float" on during a bottom-pour session:


A heaping tablespoon is just about right for a 10 lb pot, stirred in thoroughly to begin with and then left in place. Halfway through the pot, the lead-pot is stirred again, this time the activated carbon (dross) is removed. By leaving the charred sawdust on the melt for the first half or so of the casting session, a barrier is formed to slow down the oxidation of the tin, and by removing the charred dross before reaching the bottom, the sequestered impurities are removed before they can sneak through the bottom-pour spout and possibly cause inclusions.

But how do you guys who dip go about with your fluxing during the session?

(ps: I am intrigued by the Lee 20# Magnum melt furnace. The RCBS Pro-Melt 2 looks awesome, but I'm afraid the price point would put me in immediate jeopardy of death by wife. Your thoughts on the Lee for dipper casting?).

[Bazoo]

I use beeswax for flux. Between beeswax and sawdust and paraffin wax, beeswax does the best job. Maybe sawdust checks all the boxes from a scientific view, but beeswax makes for the easiest casting lead. With sawdust, the lead seems sluggish, not as flowing. With beeswax it behaves better, casts better.

I flux, then skim. Then when i start having too much dross I skim again. After a couple times adding my sprues back in I’ll flux again.

[Bigslug]

I'm not a fan of ladle casting, mainly for the fact that I don't have the eight to ten hands it seems to require, but you do bring up another legitimate concern - all the oxides and impurities will naturally float to the top. To that end, the Pro Melt is probably your buy once, cry once option for bottom pour.

A blob of SPG lube stirred into the melt seems to help clean things up. I expect for ladle casting, you'll need to do it more often.

[HWooldridge]

I tried sawdust once and concluded it just makes a mess unless you use a bottom pour pot. I use rosin flakes or old lubed bullets to flux and simply do it any time I add sprues or the surface starts looking grey and lumpy. I probably use a bottom pour more often than a ladle but am comfortable with either method.

For ladle, I use a turkey burner turned way down for a heat source and an old dutch oven to hold the lead. I let the ladle rest on the melted lead and hold the mold with the sprue to the side, then load the ladle, place the spout against the mold and rotate both 90 degrees to fill the cavity(s). Never had too much trouble with that technique.

[Wayne Smith]

When I add new lead to the pot I flux with sawdust. To reestablish the tin in the melt I flux with wax. I do this whenever my melt gets stringy, or when I see tin on the surface of the pot. Those of us who ladle pour do increase the oxidation of tin simply because we are exposing more of the lead to the air. Thus especially on a long session I may wax flux several times.

[JoeJames]

I read From Ingot to Target and learned that saw dust is good. I dip from the top after fluxing with saw dust, but I use an old GI spoon to clear off the stuff on top before I dip my ladle. I have not had any trouble; although a buddy tried it and set off his smoke alarm in his shop and back at his main house. He's not particularly a fan of it.

[ShooterAZ]

I only use sawdust while smelting, and it works quite well when combined with paraffin or beeswax. I personally wouldn't use sawdust in a bottom pour pot though. The only flux I put inside my RCBS casting pot is beeswax. I don't ladle cast so it may well have an application for that purpose, I never tried it.

[waksupi]

Stir the pot with a stick, then skim the pot.

[Walter Laich]

check reviews of the Pro-Melt 2

some concerns seemed to have occured

[Super Sneaky Steve]

I got tired of dripping pots, which waste way more time than ladle casting. Pick up a lyman ladle. It pours from the bottom of the ladle. I'm able to fill a 6 cav 45 Automatic mould with one scoop.

[gwpercle]

Pressure caster with an open top Lee Magnum Melter and Lyman spouted dipper .

While casting I flux and skim the top clean ... for me this keeps the "particulates" out of my dipper , moulds and boolits .

When fluxing I use a 3-step process , on top of melt I place some wood pencil sharpener shavings , a little Marvelux and a little beeswax ... then stir well with a little wood paddle , scraping bottom and sides . Leave the carbonized flux on top untill ready to dip boolits ... then skim the top clean and discard all the carbonized top stuff that has floated up .

The Lee Magnum Melter is a great value . I've used Lee electric pots for 45 years and never have one fail on me , started with 5 lb pot then 10 lb and then got the 20 lb LMM abot 12 years ago ... it's the best ... melts 20lbs of cold metal in 20 - 30 minutes and can keep the alloy as hot as you want it ... I wish my first pot had been the 20 lb Magnum Melter ... with small pots you waste a lot of time waiting for metal to melt ... 20 lbs gives you a good supply that allows you to cast more .
Gary

[Wayne Smith]

Let me clarify - I use sawdust to clean the melt. That is basically once and done until I introduce more lead to the pot. This is a 20 lb. pot on a gas burner. I use wax to reduce the tin back into the melt, this is done multiple times in a session as I am dumping the sprue back into the pot (splashes) and over running the mold to get complete fill in some of my molds, (more splashes) and thus am exposing a lot more of the lead to oxygen than a bottom pour guy will.

[huntinlever]

Wow, didn't realize all the replies, thanks guys. Lots to think on. I guess it's not much beeswax per session but at least here it comes at a bit of a premium - can only get it locally from an "heirloom" candlemaking place, and online I don't need anywhere near as much quantity, so given truckloads of free sawdust, well....

I also used to use dried up leaves, IIRC. In lieu of beeswax, how about cheap wax by way of tea lights, or something like this?

[HWooldridge]

Wow, didn't realize all the replies, thanks guys. Lots to think on. I guess it's not much beeswax per session but at least here it comes at a bit of a premium - can only get it locally from an "heirloom" candlemaking place, and online I don't need anywhere near as much quantity, so given truckloads of free sawdust, well....

I also used to use dried up leaves, IIRC. In lieu of beeswax, how about cheap wax by way of tea lights, or something like this?

Paraffin works, too - and it's usually easy to find; all I ever used to flux for the first few years I was casting. Only problem is that it ignites easily and burns.

[Bazoo]

I have found beeswax works better than candle wax. My experience is when using candle wax, the melt doesn’t act any different than sawdust, it’s just less messy.

I use about a table spoon of beeswax every casting session. I got some from a member here and been using it for 7-8 years now and just started to make a dent. It’s worth paying whatever it takes in my opinion as it’s a superior flux. Atleast from the perspective of the way it makes the melt act. It also keeps the dross from forming again less quickly than the others, in my experience.

[huntinlever]

OK, thanks guys. Do you use the wax for both smelting and casting, or just casting? I can get a pound of beeswax for about $15, and I know a little goes a long way so it's probably not really a big deal. Just never used it except in making lube. I can get a block on Amazon or locally, in little granules.

Edit: I believe I read that when using beeswax you stir it in, and flame the smoke, is that correct? Do you do it immediately after stirring, or let it sit for a minute or so?

[The Dar]

I use this:

https://www.hobbylobby.com/Crafts-Hobbies/Candle-Soap-Making/Candle-Making-Supplies/Beeswax-Block/p/CA50100

Lasts 3-4 years for my casting pot.

[Bazoo]

I use sawdust and candle wax when rendering wheel weights. And beeswax for actual casting.

I put a pea sized bit in my pot and let it bake about a minute. Then stir it in real good. Then skim. It makes the lead flow better somehow. I get less inclusions using it. Maybe because I think it works better I do a better job? If you go that route I’d certainly like a report of how ya like it.

[huntinlever]

I use sawdust and candle wax when rendering wheel weights. And beeswax for actual casting.

I put a pea sized bit in my pot and let it bake about a minute. Then stir it in real good. Then skim. It makes the lead flow better somehow. I get less inclusions using it. Maybe because I think it works better I do a better job? If you go that route I’d certainly like a report of how ya like it.

Awesome. Thanks, will give it a go.

[huntinlever]

Thanks - this is Amazon, it's what I used before for the lube. I liked it. https://www.amazon.com/gp/product/B00F3CNMV4/ref=ox_sc_act_title_3?smid=AQ12YB6UZDO3T&psc=1 Though it's pretty convenient to use the granules (not sure what they're called), I've found. Locally these granules are just a couple bucks more, probably go with it.

[michael.birdsley]

When fluxing with candle wax. Once you throw it in is it supposed to make a loud poof and the wax catch on fire ? Almost made a mistake one time standing to close. I was using this wax from Amazon. I’ve been making fishing jigs for sit ten years and some boolits. Never really fluxed decided to try it this summer.

https://uploads.tapatalk-cdn.com/20221202/b9fe212805fddb3a8e49ade11e37a2a6.jpg


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[Wag]

By the time I'm done smelting, I've fluxed the heck out of it and it is very clean by the time it hits my casting pot. From there, I'll use a pinch of wax from a toilet ring at the beginning and that's about it. From there, I keep it stirred up real well.

I thought I had read on here way back when that you can over flux and actually remove tin and/or antimony from your melt so I don't keep fluxing while casing and I generally stir the stuff from the top back into the melt.

--Wag--

[murf205]

I, too, am a beeswax fluxer and if you have a Dollar General store near you, they sell it in little jars in the hair care section. I don't remember the exact cost but it is pretty pure and does a terrific job for cheap.

[TNsailorman]

I bought some sawdust from a fellow member years ago when I was ladle casting. The biggest mess I ever encountered in my casting carreer. I had to use a brush wire wheel on a electric hand drill to get the stuff off the sides of my pot. Never again for me. my experience anyway, james

[Kosh75287]

My casting experience is not extensive. Since I was at a friend's home in town, there was no sawdust handy to try, so we used left-over wax from old candles. The three of us, from prior work experiences, knew the potential for disaster when introducing flammable paraffins to a very hot and molten surface. We started dropping very small amounts, at arm's length, into the pot. We had no hope that the tiny amounts used would do much fluxing, but they DID give us an indication of what to be prepared for, when using "real" amounts.
We got small "FOOF!" sounds, and sometimes a flame resembling one from a Sterno Can would linger, but covering it with a flat piece of metal fixed it. I'm kinda inclined to stick with paraffin or beeswax, since it is relatively free of impurities. With saw dust, I have no idea of what surface treatments the wood may have had, nor what they turn into, when burned.

[Bazoo]

Candle wax will ignite and poof. If you through a big gob in, it’ll overflow the pot too. Beeswax will not normally ignite because the flash point is higher. If you run your pot super hot then it will.

[michael.birdsley]

Candle wax will ignite and poof. If you through a big gob in, it’ll overflow the pot too. Beeswax will not normally ignite because the flash point is higher. If you run your pot super hot then it will.

So I need to be using less wax ? I’ll might use up this wax than get some bees wax. It’s about the same price


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[huntinlever]

Just want to say thanks for the thoughts guys. Burner arrived today and looking forward to getting at it.

[303Guy]

There was a discussion a few years back on fluxing and I mentioned that I found stearic to be a great flux. A fellow poster mentioned that a family member suggested carnauba as it is an acid. Well, so is stearic - stearic acid.

Well, it took me a year or two to finally put it to the test and indeed, carnauba is a great flux. I did a test to compare the two and found that while both carnauba and stearic work great, carnauba has a way lower flash point. It just melts into the dross, breaks down that porridge skin and leaves a dry dross with shiny beads of metal which can be largely stirred back into the melt. Stearic flashes off in a big white cloud that makes for eyebrow searing fun. So, carnauba works better than any other wax or sawdust.