tecnovist

Forge weld flux

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And for the new folks; here in the USA one can buy boric acid at the pharmacy for $$$ per ounce  or buy Roach-pruf at the hardware store for $ per pound and RP is 98% Boric Acid.

Took the words out of my mouth.

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A number of the traditional, commercial, welding mixes included boric acid.  Cherry heat if I recall had iron particles as well.

 

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Cochran, you are more than welcome, good luck with it.

Charlotte, I agree boric acid is in a lot of formulas. I have not seen any  homemade ones that contain a source of carbon though. That is what is really helpful in this mix. Lowering the weld temp of the joint really seems to help with nice solid welds, especially when coke or good smithing coal is not readily available like here in Alaska. 

Edited by teenylittlemetalguy

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Cochran, you are more than welcome, good luck with it.

Charlotte, I agree boric acid is in a lot of formulas. I have not seen any  homemade ones that contain a source of carbon though. That is what is really helpful in this mix. Lowering the weld temp of the joint really seems to help with nice solid welds, especially when coke or good smithing coal is not readily available like here in Alaska. 

The mention of traditional fluxes was just so the less experienced would fell comfortable with boric acid in a custom made flux.  The addition of powdered carbon is very new to me.  Although,  on reflection,  it seems to be an excellent innovation.  I will be trying it next time I make up some flux.

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Well for a *traditional* flux: clean quartz sand  or powdered glass is mentioned for the forge welding of real wrought iron.  I believe the use of Borax came in with the transition to using mild steel after the Bessemer/Kelly process was discovered.  IIRC it's mentioned in "Practical Blacksmithing", Richardson, during a discussion on working with the new material and the process changes needed.  In one of the Foxfire books they mention using dirt daubers nests for flux.   (really 20 mule team and roach prufe are *easy* to source and use here in the USA!)  (Note that the wrought iron fluxes are VERY HARD TO REMOVE cold afterwards)

Edited by ThomasPowers

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The home brew flux I've been using before I discovered an economical commercial flux was: 1 pt. boric acid to 3-4 pts, borax and it works well though nothing compared to Tristan's "Alaska Flux."

The commercial flux I found at the local "Wasilla" welding supply is "Petterson's #?"  I can't recall the number designation but it's NOT the high temp flux. It's primarily anhydrous borax and boric acid with a couple proprietary ingredients, one to turn it blue I'm sure. Anyway, the stuff is on the shelf in Wasilla for $26.and change shipping included. Buying a 1lb. can of "forge" welding flux starts at $50.00+ Plus shipping. The Petterson's high temp flux contains iron powder but needs more heat to melt.

As it stands  Tristan's "Alaska Flux" beats the commercial fluxes hands down. The only change I'd make it to use anhydrous borax for it's superior wetting characteristics. One of our guys did a welding demo a few meetings ago with a head to head comparison showing that while laundry borax is boiling out the water content the anhydrous is coating (wetting) the steel. Convinced me in one.

Making 20 Mule team into anhydrous borax is pretty labor intensive, it's easy to drive out the water, "Hygroscopic moisture" cooks out at 230f but it glues the borax into a hard lump. It is NOT necessary to melt the borax to make it anhydrous but driving off the hygroscopic moisture causes it's own issues. I've given it a try and it still requires a mortar and pestle to reduce the anhydrous lumps to usable powder.

However, a rock tumbler and ball bearings would make an outstanding ball mill to powder the anhydrous, charcoal and mix all the ingredients as well as possible. I mean a commercial grade product. Hmmmm. Another tool to add to the garage sale list. My list now includes: smithing tools and equipment, ball pein hammers, spinning gear for Deb and now a rock tumbler. Cool.

Frosty The Lucky.

 

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I am reading many posts and there seems to be  mix emotions on forge flux and what ingredients make it up. I have looked on several blacksmith supply places and they sell a verity of flux material. I would like to buy my first set to see how the “professional” ones look, react to the steel. Then I will try and mix my own. My question to the group is what type do I need? I would like to weld 1084 into RRspikes to make hatchets.  Here are the options.

Forge Borax, 1lb, $10.95

EZ- Weld Compound- 1lb- low heat for tool steel, plow open hearth and Bessemer steel at low temps. Contains 40% metal. $10.95

Cherry heat welding compound – 5 lb can, low heat for tool steel, plow open hearth and Bessemer steel at low temps. Contains 40% metal. $50

There are also several liquid types.

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Twenty Mule team will work adequately for you project.  There are discussions in Alchemy section which cover  forge flux in exhaustive detail including a recent one for a home brew flux that I plan on trying the next time I make up a batch.

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Understood and thank you. I wanted to buy a made up batch to see how it is suppose to work before I start mixing my own. Thank you for the help.

 

 

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So what you mean is that you want to go see someone use it who knows how it's supposed to be used  to see how it's supposed to work.  I can buy the same materials for dinner as a cordon bleu chef but I guarantee it that mine will end up a lot different...

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What Thomas said. With a little experience all the products you've listed work fine. I've been replacing my home brew 1pt. Boric acid to 3-4 pts laundry borax with Petterson's blue from the local welding supply. My next experiment will be with Tristan's "Alaska flux" but I'm just going to add some charcoal to the Petterson's.

I've done no-flux welds in my propane forge on a lark so to speak AFTER I got a weld by accident.

What you really need is a little experience welding so you can judge yourself. Welding is often a first session exercise I show students as a confidence builder. It's about proper procedure more than a specific product. An experienced blacksmith can show you in minutes and may even have more than one kind of flux you can try.

Seriously, there's more mystique to forge welding than actual difficulty. If you lived within visiting distance I'd show you how faster than it took to write our posts. It is NOT hard.

Frosty The Lucky.

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Blade welds?  Fluxes without metal particles are preferable, so the forge borax would be great.  It is also not too pricey.  For general welds, like drop tong welds, the metal bearing ones like ez weld are supposed to be better.

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Ok I give up I'm forbidden, grrrrrrrrrrr.

I can write forbidden but not post anything else?

Edited by Rashelle

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Yeah and I was just forbidden my response to your post. Grrrrr.

Maybe edit.

Okaaayyy. Now I'll try editing my edit. I've been writing a message then exiting the thread to come back and click in the text box where my message was saved and I submit it. It works reasonably well, unlike IPS SOT WARE.

Frosty The Lucky.

Edited by Frosty

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Thisis nuts I'm forbidden to reply to your reply to my reply but can post this.

Can't edit either.

Like it was said above go to an experienced forge welder and let them show you how. Use what you learn on then branch out after gaining enough experience to tell what is different. When first learning forge welding do destruction tests. At the school I instruct at due to summer being over my class size went to only 5 students for today and tomorrow. Amongst those five are 3 10 year olds. Today I brought in a portable coal forge, demoe'd forge welding a historically accurate miniature trade axe. Then had my assistant repeat the process for his first weld, followed by ALL of the students. Only one didn't do the complete forge weld. I stepped in and finished it as he was afraid of the heat. It comes down to learning it right. Nothing else magical about it. That amounted to 7 successful forge welds straight in a comtaminated fire that wasn't cleaned out. Someone in the past mixed bituminous and anthracite with coke and charcoal. With bits and pieces of wood, metal, and other contaminants thrown in.

I can write inane comments but can't finish my reply.

Those kids were at day 4 of blacksmithing. It's more important to learn how to forge weld then what flux or lack of flux.

Edited by Rashelle
forbidden

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are the proportions for your flux by weight or by volume Teeny

just wondering as charcoal is so light

 

sorry for the late reply, my post got mved and I coul not find it.

i measured by volume, that charcoal is super light.

in making this I also had good luck just using the boric acid and charcoal, but it was real runny.

thank you all for the nice comments. Would love to hear of anyone else's additions or changes they preferred.

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Have you tried graphite instead of the powdered charcoal?

Alan

I have not tried graphite, I doubt it would be any less useful I just had good charcoal available only a tiny amount of graphite.

i was thinking about adding silica sand to the mix but have not yet. We tried it out at a meeting and it was like water when used straight. 

 

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I still have a biscuit tin full of silver sand from when I first started. I haven't opened the tin for forty years...must see if there is any still in there or whether it has drifted away!

If I used flux it tended to be borax. I did try a proprietary flux that Bob Bergman sent me. That had iron filings in it. I think it was EZ weld or similar. I haven't seen the tin for a year or two.

Your flux enabling you to weld 1/16" straps sounds amazing.

Alan

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I still have a biscuit tin full of silver sand from when I first started. I haven't opened the tin for forty years...must see if there is any still in there or whether it has drifted away!

If I used flux it tended to be borax. I did try a proprietary flux that Bob Bergman sent me. That had iron filings in it. I think it was EZ weld or similar. I haven't seen the tin for a year or two.

Your flux enabling you to weld 1/16" straps sounds amazing.

Alan

thanks Alan, I was floored when I managed it. to be fair i did move my anvil right next to the forge and worked faster than I ever had, but I knew with the first blow that it worked. 

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Would think sand would promote inclusions.  It was used for Wrought iron which is generally welded at a "snowball heat"  when the sand/glass is fairly runny. It's fairly sludgy at lower heats like is used for modern high carbon steels.  Note that SiO2 isn't real active even when hot it's more of a "protective cover" rather than a clean the joint.

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