Who uses borax in the melting pot?

27 December 2015, 00:17

Jon Leary

When I first started casting bullets there is an article in the Lyman cast bullet manual that recommends using Boric acid on the melt to seal the molten lead from the atmosphere. I had some boric acid so I used it and it worked but it left a glassy residue so when that was gone I tried 20 mule team borax and that worked also. Once the lead has melted and is fluxed just sprinkle a little on top. It puffs up and you don't have to keep cleaning the melt. This works for a bottom pour. I never tried it with a ladel.

27 December 2015, 19:36

savage300phd

Jon, I have been casting for 30+ years now never have tried the borax. I do flux with Marvelux to reduce dross. I used a 20 lbs bottom pour pot. Once the lead is up to casting temperature I add non scented cat litter on top of the lead. About 1" or so. When you put the ingots on top of the litter it will melt before it mixes with the molten lead, doesn't change temperature of the pot.

31 January 2016, 18:43

450ak

Pine sawdust is a great flux and smells nice. The finer the better, although I've got some from a planet that's works too.

02 February 2016, 02:45

Uncle Grinch

I used to use the Marvelux powder and still have some left over, I believe. After reading comments on the cast boolits forum on saw dust, I pulled the box from under my table saw and have used it for many years with good results. I think the carbon generated from the burnt saw dust helps also.

My issue with the Marvelux is it seemed to cause more rust after the fact.

24 April 2016, 09:01

NormanConquest

Have'nt used borax,have used Marvelux but what I've found works quite well is Sal-
Ammoniac. I'm in the sheet metal business + we use these sal blocks to 'tin' our copper irons for soldering.They come in white bricks,just shave off a bit into your lead pot.Use VERY good ventilation as the chemical makeup is ammonium chloride.

29 April 2016, 02:08

MickinColo

I think it's interesting how some people go to great lengths to poison themselves with chemical fumes to fine the cheapest way to clean a pot of molten lead.

30 April 2016, 09:25

carpetman1

Use a layer of kitty litter on top of your melt. Ive heard many times that Marvelux causes rust and other problems. The only problem with using kitty litter is people see you in the check out line with a bag of it and they think you have a cat. You can explain that you are buying it for the target (the picture of the cat on the bag) or better yet go to a parts store and buy a bag of floor absorbent---it's the same stuff as kitty litter and much cheaper as floor absorbent and folks wont think you have a cat.

01 May 2016, 10:24

NormanConquest

My Heavens Mick,this is not the cheapest way,only the most effective,(splitting hairs here).We are not speaking of "cleaning the dross" we are talking of a true bonding of the cast projectiles that is away + beyond the marvelux process.OMI of course.I must confess hat the kitty litter is a good safe alternet as well.

02 May 2016, 03:12

MickinColo

quote:
Originally posted by NormanConquest:
My Heavens Mick,this is not the cheapest way,only the most effective,(splitting hairs here).We are not speaking of "cleaning the dross" we are talking of a true bonding of the cast projectiles that is away + beyond the marvelux process.OMI of course.I must confess hat the kitty litter is a good safe alternet as well.

My “interest” is not directed at you. It's an observation of this subject over the years. Little things like sawdust off of wood cutting. What sawdust? Is it treated sawdust? What was the chemicals used to treat the sawdust? How do those chemicals react to heat in a pot of molten lead?

Making lead alloy bullets is a toxic process to begin with. What you use to flux the melt can only add to the problem.

02 May 2016, 08:55

NormanConquest

Mick,Concerning sawdust,I only use what I can collect after cutting oak firewood. Never treated. I agree vehemently about not using something in the chemical line that I'm not aware of. In my business it has made me cautious.

06 May 2016, 03:39

Doubless

Boric acid is one of the most corrosive things on the face of the earth, as far as solids go. It has chewed holes in stainless steel in the nuclear industry, and as a result there is a Boric Acid Corrosion Control Program required of every commercial nuke out there. Further, heat just exacerbates the problem.

I won't use it for precisely that reason. It will turn a casting pot orange virtually overnight.

07 May 2016, 21:50

The Dane

http://www.lasc.us/Fryxell_Book_Chapter_4_Fluxing.htm

quote:
Some of the commercial fluxes on the market today contain boric acid, borax, or other borate containing materials (e.g. Marvelux). These materials are fluxes in the true definition of the term since they melt to form a borate glass which entrains any oxidized materials and extracts these contaminants into the molten glass phase. These fluxes have the significant advantage of being smoke-free and odorless. They are also extremely effective at removing contaminants. This is because the borate anion binds all metal cations and extracts them into the molten borate glass. Unfortunately, this includes any oxidized tin, and so the alloy is depleted of this valuable component. The borate fluxes do nothing to reduce the oxidized tin, nor do they protect the melt from further oxidation. You’ll note that this behavior is exactly opposite to that of the waxes, described above.

05 November 2016, 03:57

Jon Leary

I guess I wasn't to clear in my post. I use wood to flux the lead then sprinkle a little borax on top of the melt to seal it. Then fluxing isn't required during the casting session. I use a bottom pour. I have used Boric acid but it turns into a glassy crust. Borax just kind of puffs up into a grainy layer.

10 December 2016, 19:59

Wstrnhuntr

quote:
Originally posted by NormanConquest:
Have'nt used borax,have used Marvelux but what I've found works quite well is Sal-
Ammoniac.

+1. Ammonium chloride = Marvelux without the name brand.