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Flux when welding, yay or nae?


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I've been fortunate enough to work with some old school blacksmiths including the Shetland based toolmaker Bruce Wilcock. The consensus of opinion amongst these guys is that flux causes more problems than it solves. They suggest that using the correct steel, properly prepared, in the correct atmosphere is all that is needed for good welds. I know that some exotic steels require fluxing but for 'normal' carbon steels do you find flux a help or hinderance?

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all you need for a weld is

1) clean steel (ground free of oxide)

2) reduced atmosphere.. (no oxygen )

3) temperature and pressure

 

I guess you can weld without flux if you have a very reducing atmosphere... but the flux itself is just that..... a barrier between the atmosphere and the clean steel surface.... and it helps to float away any of the oxides that may have formed..

 

i've done canister welds where no flux was used.......but this is a controled condition..

 

I can't see how flux would be bad for a weld..... maybe if you seal it in there as an inclusion/bubble..

 

even with wrought iron....i still use borax.... its just an easy to use flux that works..!!!

 

 

Greg

 

 

ps....I was told that too... that some of the old timey german smiths didn't use any flux... pshhhhhhh

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ps....I was told that too...  that some of the old timey german smiths didn't use any flux...    pshhhhhhh

34817[/snapback]

 

 

hmm...

I believe that some sorts of flux have been used throughout the centuries...

some are more problematic than others.

 

 

 

no flux at all can and will work, but depending on the materials, forge, atmosphere, working technique etc will introduce a lot of troubles... for me, it doesn't make much sense as borax is a superb easy flux to use and does only provide little if any problems of it's own.

 

 

 

HOWEVER,... before there was borax (18XX I believe, but could be totally wrong) ... smiths often used quartz-sand (arenaceous quartz or sometimes "quarry sand")... now that is a troublesome stuff...

whilst it is a good flux it requires higher temperatures than the flux-stuff we use these days...

Thus often the material got burnt or you had some small sand-inclusions in the blades, showing as smallish-pits inside the actual material later...

That is where the believe originates, especially amongst some of the "older" smiths, that flux offers more problems than does good.

With borax, at least imho. that is no longer a valid statement. at least not for me.

 

But "quarry sand" has also a very nice advantage... which should not be underestimated...

contrary to borax which you apply to your steel OUTSIDE of the forge or maybe with some steel spoon even inside the fire, the quarry sand could be "sprinkled" (quite a bit) directly INTO the fire ... No need to remove your steel from the heat.

 

The germans, well especially in germany the use of quarry sand was fairly popular... during th 18th/19th and beginning of 20th century especially.

 

 

dan

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I don't mean to hijack this thread but we are talking about old Germans and Flux.

 

Does anyone remember their Wagner? Siegfried used ground up his old sword fed it to the geese and forged himself a new one out of the iron rich goose poop. I always wondered if the goose poop was used for a flux or if it was just to add more carbon and minerals to the blade?

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Daniel , did you order the book ??? ...My 1910 book "Forge Practice" explains it very well. The oxide is fluid without flux only at very high heat which you can achieve with iron . With steels that high temperature will burn the steel. Flux reduces the melting temperature of the oxide. :D

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I use no flux when welding wrought iron, most of the time none for mild steel, but it depends on how the fire's doing that day, and what fuel I'm using, and I always use flux for higher carbon steels.

 

flux, even borax (especially borax) can create monstrous clinkers in a coal fire, and render it useless for the rest of the day if much welding is done early on, so I'll make all my welds at the end of the day if I can help it. I don't know that the borax makes for more clinker in a given coal, but it does make it more difficult to break up and tend the fire properly.

 

propane is different, as is charcoal.

 

Imagedude, is that the same name you have on Ebay by any chance? if so, I lost your contact info earlier this year when I had a computer crash...

 

Tony

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Cool Bob,

 

I thought it might be :)

 

One of these days I'll arrange to get that anvil shipped :) had a series of small dissasters here over the last year or so :(

 

Thanks,

Tony

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Does anyone remember their Wagner?  Siegfried used ground up his old sword fed it to the geese and forged himself a new one out of the iron rich goose poop. I always wondered if the goose poop was used for a flux or if it was just to add more carbon and minerals to the blade?

34886[/snapback]

 

 

Ahhh, Mimung... There's several versions of the story, but basically, Wayland files down a sword, feeds it to geese, smelts the poop and cuts a competing smith clean through his armor. In 1936, Doctor of Engineering J. Heddaeus published the results of an experiment recreating the smelt in Das Werk. The result was high-carbon, nitrided steel. A second paper, from the same era in Rundschau Deutscher Technik, describes results of similar experiments as such:

 

...If these filings would now be welded together, newly filed, combined and welded, after many repetitions and hardenings it would have to endow it with a body composed in a mosaic-like way and very uniformly of tough, hard iron and extremely hard carbide (iron and carbon combination,) and nitrite (iron and nitrogen combination.)

 

You can guess where I'm going with the smelter. I'm certainly saving all my filings. ;)

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