What do you use for welding flux?

[Tom Lewis]

I have made lots of Damascus blades using twenty mule borax and boric acid. It works well, but is messy, eats the bottom of the gas forge, splatters and burns any exposed flesh.

I heard about using kerosene for flux. I tried it, and it does work, however it leaves edges that don't weld well.

I know some don't use flux. With the trouble it takes to make a billet, I am hesitant to try fluxless welding. Maybe I should.

The last I did I used anhydrous borax. It is expensive compared to 20 mule team borax, but it doesn't take near as much as the 20 mule team, and it works well.

I was planning to post a picture of my latest knife made with kerosene flux, but the forum has changed, and I can't see anyway to post my picture.

 

[Atlas Knife Company]

Fluxless. Clean your steel properly, MIG weld and use propane, and you don't need flux.

 

[Don Hanson III]

I have tried it all and still use borax.

 

[Lieblad]

I have made lots of Damascus blades using twenty mule borax and boric acid. It works well, but is messy, eats the bottom of the gas forge, splatters and burns any exposed flesh.

I heard about using kerosene for flux. I tried it, and it does work, however it leaves edges that don't weld well.

I know some don't use flux. With the trouble it takes to make a billet, I am hesitant to try fluxless welding. Maybe I should.

The last I did I used anhydrous borax. It is expensive compared to 20 mule team borax, but it doesn't take near as much as the 20 mule team, and it works well.

I was planning to post a picture of my latest knife made with kerosene flux, but the forum has changed, and I can't see anyway to post my picture.

I use 20 Mule Borax. My forgewelding is usually ornamental work or steel tool inserts.
Anhydrous borax is sort of pointless because regular borax becomes anhydrous as its melted on a workpiece. But, anhydrous is nice that it does not 'foam up' upon initial contact to hot steel. Also anhydrous needs to be stored airtight, otherwise it absorbs moisture from atmosphere.

 

[jdm61]

Anhydrous is also kind of pointless where iIlive because anything is going to become "hydrous" quickly in Central Florida humidity.

 

[A.McPherson]

You can also make your 20 mule team into anhydrous by baking it, but I don’t know that it’s any cheaper to do that considering time and power costs...

 

[Lieblad]

You can also make your 20 mule team into anhydrous by baking it, but I don’t know that it’s any cheaper to do that considering time and power costs...

Baking will release about 50% of its water. To be anhydrous, its needs to be melted.
None the less, its still extra expense & hassle, fairly pointless if using as welding flux.

 

[Salem Straub]

No flux works great. Just tack up a well cleaned stack like normal, put into reducing fire, heat to welding heat with good dragon's breath out doors, forge weld under hammer or press. Super solid, super clean.
Same thing works, with kerosene. I do multibar all the time with just kerosene, fishmouth/birdsbeak tip welds with no flux or kerosene, ferry flips with just kerosene, tiles with edge bars... you get the picture. It's just about forge atmosphere and smacking it together everywhere right away.
Here's some turkish with a cruforgev edge from recently, just kerosene... no TIG or MIG up the seams. Forge welded bolsters too.

Some Parquet twist from a saber I made not long ago... also no flux at all for the layer count, then nothing but kerosene for the two-bar final weld.

I really love how clean it is... enough that you normally can't tell at ALL that it's pattern weld until etching.

Occasionally I still use flux, for jellyroll in particular since it's so gnarly a weld... or to fix the occasional problem that may arise. In this case I like about 2/3 20 Mule team, 1/3 boric acid (roach prufe) as the boric thins the flux a bit when wet and helps it to melt earlier.

 

[Stacy E. Apelt - Bladesmith]

I have started using kerosene. I clean the bars on the grinder with a 50 grit belt. Then, weld up the stack on all the corners and weld the rebar handle on ( weld the handle on really well!) I stick it in a tall can of kerosene with a flip up half lid ( used in restaurants for sauces and such). It could just as well be a big metal bucket of kerosene with a wooden board or sheet of metal over the top. You can put several billets in and they can sit there for weeks waiting to be welded ... no rust or other issues. When ready to weld, take one out, let it drain off the excess kerosene, and stick it in the forge. Once it is at welding heat, press/hammer to set the weld and continue as with any other billet. If for some reason you have to stop part way through welding a billet, let it cool to black heat and stick back in the kero bucket. Kero is surprisingly hard to light on fire as a liquid.

I find it easier to hand set the welds with kero than with borax ... and there is no flying lava.

Obviously, keep the kero bucket away from the forge and sparks, and keep it as covered as possible. Cutting some slots in the wooden or metal cover will allow the rebar to stick out but keep the kerosene covered. Place it where it won't get kicked over either. When there are no billets in the kero, cover as tightly as possible. A weight on a round piece of plywood will work.

 

[Tom Lewis]

I just remembered how to post a picture. This blade was done with kerosene.

Salem, thanks for the beautiful pictures and advice.

Stacy, when I use kerosene, I loose some material where the edges don't weld very good.

I set the first weld with a hydraulic press with flat dies. Maybe I will try the flux less method.

Where I live in the dry desert (dry most of the time) anhydrous borax doesn't go bad. I have had some for several years and it has not absorbed any water that I can tell.

 

[Fred.Rowe]

I've been using K-1 for a couple of years and prefer it over other techniques. I find it's cleaner in between layers. I find borax to be so sticky small bits of grit or steel get lodged between the pieces. Kerosene works well on odd shaped pieces as well. There is nothing more satisfying than a feather pattern without inclusions.