powder laundry soap verses Borax

[loader]

Hey Guys,

I use Borax for flux. while smelting ingots. My wifes buys borax to control ants, so I use to flux the pot. It's only four bucks for four pounds. I know I can use saw dust and it would be free, but I really don't like relying on other people to supply me anything. Yeah I know, go to a lumber yard or home depot and get it. I could. How well does saw dust work?

[Blammer]

works fine for me, I just ad a little and stir, of course I'll use about anything for flux

[runfiverun]

the sawdust is for the carbon it needs to be charred into ash then you need an oxygen free zone to reduce the oxides back into the melt.
hence the fire part.
borax does fine but remember it will hold tin in suspension as well as other metals in the mix.
and it is hard to get them to release back into the alloy.

[btroj]

Is your wife using borax or boric acid? Different things.

I have seen boric acid used as a flux, similar to Marvelux. What a mess. Boric acid is also used to kill ants.

I will stick to sawdust of a paint stir stick for fluxing. They just work.

[loader]

the sawdust is for the carbon it needs to be charred into ash then you need an oxygen free zone to reduce the oxides back into the melt.
hence the fire part.
borax does fine but remember it will hold tin in suspension as well as other metals in the mix.
and it is hard to get them to release back into the alloy.


borax does fine but remember it will hold tin in suspension as well as other metals in the mix.



I know that you're not making this up... so,.. how do you know this? What's the solution to clean it all?

[theperfessor]

I've never used anything besides sawdust or vegetable waste for flux so I can't say if there are other, better methods. But I've come to believe that this is a cheap and easy way to clean your melt. Bret4207 (and many others here) tout using sawdust and stirring with a dry wooden stick. I've processed a lot of scrap lead including roof sheathing covered with tar, drain pipes filled with, uh, "residues", wheel weights, and "mystery metal". Sawdust, stirring with a hardwood stick, and good skimming has worked every time.

[dragonrider]

Sawdust works like majic, but only after it chars completely, don'[t go mixing it before that happens and once ti does liftup ladlesful of lead and char anf from a hieght of 6 to 10 inches pour it back into the pot,This will keep your lead moving virgorously getting a lot of contact with charred sawdust. If you pot is dirtry from other psuedo fluxes sawdust will clean it up. I have been using it for some years and will not use anything else.

[captain-03]

Sawdust in my pots - always!!

[cbrick]

I know that you're not making this up... so,.. how do you know this? What's the solution to clean it all?

Here it is explained very well in plain simple english. Chapter 4 is on flux.

http://www.lasc.us/Fryxell_Book_textonly2.pdf

Rick

[John Boy]

borax does fine but remember it will hold tin in suspension as well as other metals in the mix.
and it is hard to get them to release back into the alloy. I only get ash in my dross. I've been using borax for about 3 years and cast several hundreds of pounds a year. Plus, in a 20 lb pot, after fluxing twice with borax, I don't see any additional dross to the bottom of the pot

[loader]

So cleanliness of the lead creates better flowing which causes better mold fillout (raise surface tension and viscosity).

The carbon in the wood creates a porous sorbent which collects impurities once burned into carbon...

and allows tin to go back into a (metallic state, and not oxidize). I'm not grasping this concept).

[Bad Water Bill]

I have used borax for years for a cleaner laundry AND in my SHOES to get rid of that nasty smell.:bigsmyl2:

[noylj]

I'm too old. I use wax, bullet lube, and industrial fluxes and ignite them all when they start to really smoke. A good DRY wooden stir stick is good, too, but I still use the old restaurant drain-spoon I started with about 35 years ago.

[williamwaco]

================================================== ==


I'm too old. I use wax, bullet lube, and industrial fluxes and ignite them all when they start to really smoke. A good DRY wooden stir stick is good, too, but I still use the old restaurant drain-spoon I started with about 35 years ago.

================================================== ==

Me too. I have used sawdust too. It does a good job but the smoke really chokes me and messes up my eyes and I have to scrounge it from friends with wood working shops.

I use rejected bullets which have been lubed with alox / beeswax when they are avaialable. Most of the time, I use scrap candles. If the melt is hot, the fumes will ignite and there will be no smoke.

[geargnasher]

So cleanliness of the lead creates better flowing which causes better mold fillout (raise surface tension and viscosity).

The carbon in the wood creates a porous sorbent which collects impurities once burned into carbon...

and allows tin to go back into a (metallic state, and not oxidize). I'm not grasping this concept).

Do you have any background in inorganic chemistry, even a high-school class? If you have, this might help you understand. When you melt and heat an alloy, the surface oxides of the metals float to the surface. Continued contact of the surface with the oxygen in air promotes further oxidation of the metals. Tin oxidizes out of the melt much faster than lead, and tin is needed for improved castings, plus is expensive to add back at $18/lb, so you want to preserve it, rather than skim it all off and throw it away.

We know that sawdust, or ANY hydrocarbon smoldering on the surface of molten lead alloy, is actively inducing a reduction/oxidation reaction (or REDOX reaction), because of the chemistry involved. PbO2 + SnO2 + HC --> Pb(s) + Sn(s) + CO2(g) + H2O(g). That's not balanced and not all that goes on, but it's a crude representation of the reduction of the metal oxides and the oxidation of the hydrocarbons that is taking place. The last stage of the Galena smelting process that yeilds lead from ore is to introduce the molten metal to carbon monoxide (CO), which readily reduces the PbO2 to Pb and yields Pb elemental and Co2 gas.

Sawdust does more than just reduce oxides, it actually fluxes the melt by drawing out and removing the things that are considered impurities to boolit casters. The borate fluxes capture the valuble tin and remove it, and serve only to seal the melt's surface from further oxidation. The only use I can think of for borate "flux" is with pure lead being cast at very high temperature, in excess of 800 degrees.

Sawdust works better than borate glass in any situation I can think of. So to answer your other question, SAWDUST is your solution to clean it all. Just stay away from sawdust that has poisonous stuff in it like formaldehyde in plywood sawdust, or pressure-treated lumber dust.

Gear

[loader]

Well I went to home depot and got sawdust from the vertical saw for cutting plywood. Guess I need to toss it, according to you.

Do you have any background in inorganic chemistry, even a high-school class? Nope.
Thanks for the write up, gear, but I didn't have chemistry in HS. Lost cause. I can gather that Carbon gathers inpurity, and blends tin in the alloy. I used Borax to flux, and did not remove anything, that I could see anyway, form the pot.

So by using the borax with WW's what happened to the tin? It's in suspension? And will not do it's job... help lead to fill out the mold?

What can I do to fix the ingots I made with fluxing with the Borax? Will the sawdust bring tin out of suspension?

[cbrick]

Well I went to home depot and got sawdust from the vertical saw for cutting plywood. Guess I need to toss it

You can use it, it will work fine but you do need to make sure that you have really good ventilation. I have used a huge amount of sawdust from plywood with no problems but I have a strong vent fan in the ceiling about 36 inches above my pot. I can stir the melt with the sawdust smoking like crazy and standing next to the pot I can't smell it. If your ventilation isn't good enough to remove all of the smoke just flux outside.


I can gather that Carbon gathers inpurity, and blends tin in the alloy. I used Borax to flux, and did not remove anything, that I could see anyway, from the pot.

Yes, the Borax will remove impurities such as aluminum, copper etc, it will also remove the tin, not something you could see looking at the melt. Sawdust works by a different mechanism than Borax, the sawdust will "reduce" tin. Reduce in metallurgy simply means to put the oxidized tin back into the melt (alloy).


So by using the borax with WW's what happened to the tin? It's in suspension? And will not do it's job... help lead to fill out the mold?

Correct, if the tin isn't there it can't help much. On the bright side WW has only about 0.5% tin anyway unless you have added additional tin to the melt.


What can I do to fix the ingots I made with fluxing with the Borax?

Simply flux with sawdust and if you wish add up to 2% tin just before fluxing.

Don't feel bad, I used Marvacrap for several years. One of the very happiest days of my life was the day I discovered sawdust and threw the Marvacrap in the trash can. I wouldn't allow that horrid stuff on the property again much less in the shop or anywhere near my casting pot. It will coat the inside of your pot with black rock hard borate glass, to remove it you'll spend the afternoon with a stiff wire wheel in a drill motor creating copius amounts of toxic dust. Do this outside and wear a quality dust mask.

Rick

[geargnasher]

Well I went to home depot and got sawdust from the vertical saw for cutting plywood. Guess I need to toss it, according to you. I can't assume that you have a dedicated, safe casting setup with sufficient ventilation to keep you from huffing bad fumes, hence the caution. Like Rick said, plywood sawdust is fine as long as you don't breathe it. Pressure-treated lumber, while not at bad as it used to be before the EPA banned the arsenic content, it does contain significant amounts of copper compounds and other stuff you shouldn't ever breathe.

Thanks for the write up, gear, but I didn't have chemistry in HS. Lost cause. I can gather that Carbon gathers inpurity, and blends tin in the alloy. I used Borax to flux, and did not remove anything, that I could see anyway, form the pot. Uhh, not exactly. You can't see tin in suspension without an electron microscope. The carbon is reacted chemically and changed into carbon dioxide gas. The other part of the chemical reaction (redox) is that the lead, tin, and antimony oxidesgive up the oxide part and they are transformed back into pure metals. The ash that remains together with some unburned carbon actually does act like a physical sponge, soaking up impurities. Sort of. It's more complex than that, but that's the gist.

So by using the borax with WW's what happened to the tin? It's in suspension? And will not do it's job... help lead to fill out the mold? The tin and other metals are in suspension with the borax, not the liquid metal. The borax sucks them up and holds them forever. You throw away the tin with the dross, no way around it. A small amount of tin helps fillout by creating an oxide barrier to the molten lead as it flows, like a shield. The tin flash-oxidizes on the surface of the lead, and since tin oxide is more flexible than lead oxide, it actually makes the lead flow better by keeping the lead surface from oxidizing as it flows into the mould. Basically, tin makes lead flow like water instead of pancake syrup.

What can I do to fix the ingots I made with fluxing with the Borax? Will the sawdust bring tin out of suspension? No, once the tin gets sucked up by the borax, it's gone. Probably not anywhere near all of your tin was trapped by the borax, so don't worry too much about it, but some was lost to be sure. Just add a half-percent back and you should be fine.

Hope this clears it up some,

Gear

[MtGun44]

The tin is "rusted", or oxidized by combining with oxygen in the air. The is like iron
rusting or a very slow version of burning. To reverse the process, you would be turning the
rust back into iron, and in the case of the tin oxide, you are pulling the oxygen back
off of it to give yourself metallic tin again. Reversing the chemical reaction that is
oxidation of the metallic tin into tin oxide. Tin oxide isn't a metal, won't melt into
the alloy. By removing the oxygen, you release the pure tin and it can then melt
back into the alloy.

Maybe that is a bit clearer.

Bill

[geargnasher]

Good explanation, Bill.

Gear

[loader]

What can I do to fix the ingots I made with fluxing with the Borax? Will the sawdust bring tin out of suspension?

Geargnaher said...........

No, once the tin gets sucked up by the borax, it's gone. Probably not anywhere near all of your tin was trapped by the borax, so don't worry too much about it, but some was lost to be sure. Just add a half-percent back and you should be fine.



Ok... first off thank you all for spending the time to help me to try to understand the chemistry behind fluxing. Even though I do pluming and use flux, I don't understand the chemical reaction of fluxing...LOL Anyway..... I do know that it cleans and allows the solder to flow and in casting the TIN aids in flowing.

So in the gist all isn't lost when I used borax. Now... according to geargnasher, not all the tin is was trapped in the borax so I can add back some tin....1/2%?? If I use lead free plumbers solder it consists of 95% tin 5% antimony... that's a pound spool. 1/2%.... what's 1/2%? Lyman says #2 alloy is 18 pounds lead, 1 pound tin, and 1 pound antimony... that I can relate too.. but 1/2%? Care to tell me if I have a pot full of lead say 18 pounds... of 18 pounds how much is 1/2% tin that I need to add?

[randyrat]

First, try to cast with your alloy. If it cast well, nice boolits don't worry about adding any Tin.

I only add Tin when I have problems casting nice filled out boolits.
Most the time it's a temperature problem or contamination problem in the mold cavities that hinders casting
OR
I add Tin to lighten n a particular boolit a tad...ie- Boolit is cating 243 grains and I want 240 grain boolits. By adding some Tin my boolits will be closer to 240 gains. Tin will also toughen without the brittleness or Antimony.

I also use sawdust

[milprileb]

Moving my question to a separate thread so as not to confuse the OP original focus.

[cbrick]

of 18 pounds how much is 1/2% tin that I need to add?

5 3/4 ounces.

randyrat is correct, its not mandatory to add tin. Many people do, I do. If your going to add tin to a Pb/Sb alloy keep the Sn percentage at or below the Sb percentage.

To figure out the tin percentage I do this.

18 pounds lead X 7000 grains (there is 7000 gr in a pound) = 126000 gr. and 2% of 126000 is 2520 gr. The formula for converting grains to ounces is .00229 so multiplying 2520 grains by .00229 gives you 5.7708 or 5 3/4 ounces.

I convert to ounces because I weigh my ingots and tin on a postal scale that weighs in ounces.

Rick

[loader]

thanks Rick.... appreciate it. I have .00218 on my scale for 1 ounce... 5.5 or 5.75 whatever...LOL

[skeet1]

I thought that saw dust could not possibly work but the cost was inviting so I tried it. It works great and I wouldn't use anything else. Compared to using bullet lube in the pot and making nauseous smoke, the wood smoke is not near so bad. You can also ignite the sawdust just like you did the bullet lube with a lighter once it starts to smoke.

Ken

[runfiverun]

this thread brought a tear to my eyes......
just so's you all know.
remember that the saw dust is half of the equasion.
you also need a oxygen free barrier for it to work.
hence the fire.
i use the saw dust, and old candles or failed flux.
in the garage plain sawdust on top of the mix [and yes sometimes marvelux I hate it but it's a trade off. i would rather lose the small amount to the borax than the big amount to the air]
iv'e tried the kitty litter, and it does work as a heat barrier,and maybe possibly a fluxing agent once it breaks down [doubt it though]

[nanuk]

for sawdust, grab a chainsaw and an old log.... make your own

I've even read somewhere folks put oil or melted wax in with the sawdust to cover both bases at once.

[cbrick]

I've even read somewhere folks put oil or melted wax in with the sawdust to cover both bases at once.

When using the sawdust what is it the oil or wax supposed to do?

Rick

[plainsman456]

And you do not need to sit over the pot when waiting for the sawdust to burn down.
Sometimes I think folks don't use enough sawdust when smelting or casting.

[geargnasher]

When using the sawdust what is it the oil or wax supposed to do?

Rick

It provides extra, more volatile hydrocarbons to be oxidized (combusted) near the surface of the melt, and provide a very high carbon monoxide enviroment at the surface, which accelerates the reduction process. Basically adding wax/oil to the sawdust is like adding bleach to your laundry along with the detergent, a little extra "kick".

In order for reduction to occur, oxidation must occur also simultaneously. The hydrocarbons are oxidized while the elemental metals are reduced. Oxidation is enhanced by burning hydrocarbons, and grease/oil/wax burns a little better than sawdust at 650 degrees, so it enhances reduction.

When I smelt dirty scrap, I pour a cup of diesel oil on top of the mess when I light the pot, the resulting smoky, sooty, poorly-burning flame makes lots of carbon soot and carbon monoxide which is a fantastic enviroment in which to melt lead. It reduces oxides constantly while the scrap melts, and consumes almost all of the oxygen in and around the pot, preventing further oxidation while melting. It also adds BTUs to the lead from the top, and speeds the smelting process while saving a lot of propane. Once I skim the junk, I use sawdust and a large stick to stir, scrape, and FLUX the remaining suspended junk and contaminant elements out of the melt.

Since I started using Glen Fryxell's tips on fluxing, my boolits have improved. I was able to get very clean lead before, but it seems that the sawdust removes stuff that can't be seen and is a hindrance to casting. Aluminum and calcium are a couple of common contaminants in WW that are removed with sawdust, and muck up fillout when casting.

Gear

[nanuk]

yeah... kinda what Gear said
I wish I could remember the post about oily sawdust.
IIRC, the idea was the sawdust helps clean the dirt and crud, and the wax/oil helps the charred wood reduce the metals back in from the clips and crud that float to the top....

[loader]

Fryxell doesn't mention diesel fuel, but I see the process.... carbon, which wood has after burned. In a pinch charcoal would be the same.... and anything that has carbon.

Looks like sawdust accomplishes it all and it's free!!!.... removes impurities, reduces tin (which aids in casting mold fillout), and protects against oxidation.

Guess my next question would be is, how much sawdust is needed for how much melt?

[alamogunr]

Every so often I go to the local lumberyard(owned by a friend) and get an ice cream bucket full of sawdust. I'm sure it is 90% pine. I create quite a bit of sawdust in my shop but I vacuum it up along with just about everything else that I make a mess with. It is too easy to get clean sawdust to bother with whatever is in the shop vac container.

John
W.TN

PS if anyone wants a can of Marvelux, they can have it for postage.

[rintinglen]

In smelting ingots from dirty metals, primarily range scrap and wheel weights I formerly used old motor oil. I have since abandoned that practice, but it worked very well. A half cup added to a forty pound 10" skillet of melt and immediately ignited added heat to the melt, reduced oxides, and initially made a dense black cloud that vaguely resembled a burning tire. Not everything that works is a good idea. Now I use sawdust for ingots and candle wax in my pot.

[cbrick]

Now I use sawdust for ingots and candle wax in my pot.

The sawdust used when making ingots will remove possible contaminates such as aluminum, calcium, zinc etc. It’s fairly doubtful though that a single fluxing will remove all possible contaminants in the alloy, a great start of course but additional fluxing as in the casting pot will remove more of any that may remain.

By using the wax in the casting pot you’re missing out on the opportunity to remove more of any possible contaminants. The wax will not, cannot remove these contaminants, reduce tin yes, remove any remaining contaminants, no.

So I just have to ask, why not use the sawdust in the casting pot as well?


PS if anyone wants a can of Marvelux, they can have it for postage.

Geez, if I still had any Marvacrap around here I would be willing to pay the postage, cheap way to be rid of that horrid stuff.

Rick

[cbrick]

Guess my next question would be is, how much sawdust is needed for how much melt?

I use about 3/4 to 1 inch on top of the pot, enough so that when it's burnt to ash there is enough ash to completely cover the top of the melt.

Rick

[Ozarklongshot]

Ok Now I have learned more than I know what to do with. All great info. I have never lit the pot. My BP pot is in the shop part of the house. Exhaust fans suck all smoke out and heat out. Not sure how that would work with fire. I will start cleaning my WW and junk outside now and will try the sawdust. That many people can't be wrong. Also thanks for the links, more good edumacation for this ole hillbilly

[cajun shooter]

I just wanted to say that if any of you gather up saw dust from Home Depot or Lowe's or any other type of store that cuts wood for the customers, be careful. If any treated lumber is cut then that sawdust contains toxic type of materials. We had some guys that were new on a job that built a fire to keep warm. They had the fire in a 55 gallon drum and were standing around it. Several had to go to the hospital with problems from inhaling the fumes. Pat Marlin of this forum has a wood shaving that he sells for $20 a box to your door. I have been using it for over three years with great results. Not only is it a great flux but it has a very pleasant smell that my wife loves and that is a big plus. After I finish my flux, I add another pinch to cover the alloy in my pot and leave it. This gives the room a pleasant odor.

[Longwood]

I have been casting since back in the 70's.
The use of sawdust for fluxing is one of the very best tips I have learned on this site.
I use pellet stove pellets.
I wet a few and then let them dry before use in my pots.
A 40 pound $5 bag will turn into about four bags of fine chips that will last many, many years.