Fire Welding Flux

[tecnovist]

Hi fokes ---Wish you well---- I need to know what the Chemical name or names are for the flux's that is used in Fire Welding --and is there more than one thats used --- or any info about flux --- thanks
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[rusty_iron]

Gday tecnovist,

I use Borax. you should find it with the laundary items in the supermarket.

Yes there are commercial fluxes, but generally they are expensive and contain borax as the main ingredient.

try reading this site: What is Borax?

Regards
Rusty_iron
Brisbane, Oz.

[Hillbillysmith]

The chemicals found in the flux that I have are; Boric Acid and Borax.

[matt87]

Some smiths use clean sand. Others use sand daubers' nests and I've heard of some smiths using charcoal ash. English smiths traditionally didn't use flux; they pretty much relied on having a clean fire and not producing (or brushing off) the scale from the joint.

Common laundry borax is boraxdecahydrate which means it has 10 water molecules per every one of borax. This means when you apply it it will whizz around for a while. You can buy anhydrous borax (farrier suppliers I think, and ceramic suppliers). You can also heat a tray of hydrous borax in the oven for a couple hours to make partially anhydrous borax, or heat a tray to melting point in the forge to produce anhydrous borax.

[ThomasPowers]

James Hrisoulas once posted this flux recipe:

"Flux mix is as follows:

5 parts anhydrous borax
2 parts powdered boric acid
1 part powdered iron oxide (the real STUFF NOT the concrete dyes)
1/2 part Flourspar
1/4 part sal ammoniac

This stuff sticks most anything together"

[tecnovist]

rusty_iron ---Hi thanks for the link and thanks to others who posted it's interesting

[rusty_iron]

your welcome.

Rusty_iron
Brisbane, Oz.

[jjh]

If I'm welding mild steel together I rarely use a flux unless I'm welding say 1/16th sheet to a bit of 3/4" x 1/2" but then I'm a british smith taught by traditional smiths. Over here we've a product magi weld that's just anhydrous borax and iron powder i've got a bottle and have experimented and found it useful when trying to get the scarf tails to wash in.

I've also made the Jim Hrisoulas recipe flux and it it excellent for pattern welding steels containing crome I mainly use it on my initial welds and unknown steels. If anyone could tell me why we add iron oxide when it's what we're trying to dissolve I'd appreciate it. I also assume is in if to help it flow.

[tecnovist]

well i could be wrong but it mat act like a wetting agent-----so to speak---- the iron oxide may be attracted to it ----

[jimbob]

I wonder if I could use the Iron/steel dust below my sander/grinder and mix it with my Borax...seem like I read somewhere in one of the old books I have that that is what they used to do...any one try this?