Making my own flux

[Benona blacksmith]

That was because of copy and paste. I didnt mean to highlight it.

[Steve Sells]

cast iron is not the same as iron, but prove me wrong and  do it

[Frosty]

How old is that information? 30 years ago you COULD weld at low red heat with: Cherry Heat, Easyweld, etc. but the EPA took a look at what was in them and the old claims are no longer true. 

Frosty The Lucky.

[Irondragon Forge ClayWorks]

I have an old box of Cherry Heat flux and the visible amount of iron filings is nowhere near 40% not sure if the filings are cast iron though. It does a good job of welding though not really any better than Borax by itself in my observations.

[Frosty]

How old? I was visiting a smith in Central Wa. around 1992 and he did a red heat weld with Cherry heat but said it was the old stuff and no I can't have any. 

From what I've seen of the newer "forge welding" fluxes the plain old Peterson #2 blue from the welding supply works just as well. A 1lb. can was $26 and change from the gas: welding, brazing, etc shelf at the local welding supply. It lists boric acid, borax and something proprietary, probably what makes it blue. Peterson #1 yellow has iron in it if you prefer powdered iron. 

The borax has to be anhydrous as it just melts and covers hot steel. It works as well as Swan and Black Magic I've participated in head to head tests with those. Nobody mentioned to the demonstrator, that swore loudly nothing was worth spit except the can of Black Magic he brought up with him, that we'd switched his flux while he was talking. Swan, Black Magic, Peterson #2 blue. solid fast welds all, no comment from the demonstrator.

It works a treat for me.

Frosty The Lucky.

 

[Benona blacksmith]

I found one recipe that calls for 10% boric acid  50% iron powder  and 40% slag. I understand these recipes aren't a solve all solution. 

[Irondragon Forge ClayWorks]

I'm not sure how old mine is, but the label that was on the wood dove tailed box looked like from the early 1900s or so. I bought it off of eBay sometime in the early 2000s and it is still loose powder not caked. I use it very sparingly once in a while welding difficult steel.

[Benona blacksmith]

Iron powder is "pure" iron right?

I have found a source for cast iron powder. It's used as an alloy in pyrotechnics. This may save me some time.

[Benona blacksmith]

I have also found iron filings. I'm assuming it's made from filing cast iron. It is used to make sparklers.

[Rashelle]

Almost immediately upon learning to blacksmith I was fascinated with the magic of forge welding. So rather then doing my requisite 50 good nails for the apprenticeship at Fort Vancouver I jumped ahead and started forge welding. That was a little while ago. I've experimented with all sorts of concoctions, including sand from the bags that were left behind from redoing the brickwork on the coal forges. (Works fine BTW). All the way to no flux welding. Main thing really is the person doing the weld's. Myself and another blacksmith would bring in new concoctions all the time. It seems to me to really come down to timing, temperature, pressure, and cleanliness. Those are the four aspect I tell my students to pay attention to. Much of the time I just use borax, (I mainly use a propane forge naturally aspirated anymore) every once in awhile if there is a chance the material may shift I'll use anhydrous (which like Jennifer pointed out is chemically different). If the students are having a hard time I will bring out the magic fairy dust (thank you Mark Aspery for the name for my little mix). All the magic fairy dust is is roughly 50% powdered 1095 and 50% anhydrous borax. I've used iron filings (from a chemical supply) in the past. And a few months ago went to the bandsaw took a bunch of the filings from it mixed it very roughly 50/50 with anhydrous borax. Then proceeded to do oops I lost my heat red/orange heat tack welds. Consistently. Works the same as iron mountain, or, mixing powdered 1095 with anhydrous. I'll be demoing this and "magic fairy dust" low temp tack welds at the NWBA mentoring center event in June. In the end it really doesn't have to be complicated. 

[Frosty]

50/50 Rashelle eh? I have both guess I'll have to give it a try. 

And the list of recipes has been linked, looked through them and I don't know what to say. I withdraw my opinion. 

Frosty The Lucky.

[Benona blacksmith]

NWBA flux-recipes

Its flux: E

[Rashelle]

I've been real sloppy with my measuring and proportions lately Frosty. It's still been working. My initial ones were precisely measured by volume. Also the bandsaw filings one was really sloppy measuring . Just grabbed a handful threw it in a can and added what anhydrous I had within reach which was a sloppy measurement. I'm not sure yet which I like better. Both seem to compare to iron mountain in useability to do an initial low temp tack. Using 1095 is a finer product that is a little cleaner in the fire though. Not so clumpy looking when you take it out. I demo'd it again today using the bandsaw filings.

Oh yeah thank you Benona for the link. I'll try to remember to email Steve my recipe.

 

[Frosty]

I didn't get out to the shop today but I have anhydrous and several spray coating powdered steels that were gifted to me a few years ago. I'll give it a try. I hear so much wild speculation from folks just starting I'm gun shy. Reading through the lists of ingredients on that chart gives me to wonder if some folks aren't just messing with the gullible or it even matters what you use for flux. I mean really 70% crushed glass and 30% crushed marble? Others look like a laundry list from a 1960s chemistry set. 

Some ingredients I recognize as strong fluxes but dangerous, DON'T breath the fumes toxins.

While I'm rooting through the bottles of powdered metals I might grab the stellite and see if that works. Might make a pretty layer in a billet, eh?

I can also chuck up a piece of RR rail in the band saw and collect the cuttings. 

Anyway, I can live with an eyeball 50/50 Rashelle, it'll tell me all I need to know, I'm pretty sure I'm wrong already. Now to find out how wrong, it's the joy of being on the learning curve.

Some of those ingredients still has me shaking my head.

Frosty The Lucky.

[Rashelle]

Oh I did try a version with leavings from the belt sander too. That did not work well at all. Had to scrape it off to get it to weld.

[Frosty]

4 hours ago, Rashelle said:

Oh I did try a version with leavings from the belt sander too. That did not work well at all. Had to scrape it off to get it to weld.

Nah, grinder leavings are too dirty, carborudum grit is only going to make inclusions. I just looked up some particulars, it doesn't melt it can be dissolved in molten iron or sublimes at 2,700 c.

Saw cuttings are just what was in the saw cut. I have a pan I put under the blade to catch cuttings or they tend to fill the bed of my cut off saw. It lets me keep different metals separate too. I have different coffee cans.  Yeah I've been kicking doing some canister billets around. Been wondering how long curls of high carbon swarf from the drill press will look incorporated in finer saw dust of lower carbon steel. 

Frosty The Lucky.

[jlpservicesinc]

There are stories for a lot of flux mixes. 

i use the cooked more or less to eliminate the puffing up factor. What I did find was the flux eats the steel pans it is cooked in. This adds iron to the flux.  The other thing that is really neat is the fact that it takes about 3.5-4 to 1.   In other words, it takes 3 or 4 tins melted down to make  1 tin of the final crushed up flux. 

The advantage is the flux is now condensed and many times if the fire is neutral I can take the pieces out of the fire get the tack weld or weld and then put it right back in the fire as the flux is not oxidized.  Sometimes this wetting out can last a few welds with no reapplication of the flux. 

As pointed out forge welding can depend simply on experience and day.  Each person has a good day or a bad day. It doesn't really jive.  What does happen though as ones experience increases the ability seems to get more consistent and this also leads to welds that would not be possible by others increasing the Awe factor.

Some days I am a forging and forge welding God. Other days I'm a noob even though I have made the item 2000000 gizzilion times. 

I prefer the flux I make even over commercial anhydrous borax.  Something to keep in mind is chemically there really is only a difference in water content between hydrous and anhydrous (PENTA hydrate vs decahydrate borax) 10 moles of water vs 5 moles of water. 

 

Again the flux I make eats the pans so picked up some iron/carbon from the metal itself.  Does it make a difference? I don't know.  

Most say based on rogue information that the elimination of O2 attacking the steel is the main reason for using a flux. I disagree it is the main important point.

 

The most important point is to liquify the scale at a lower temperature. thus offering direct molecule to molecule contact. 

 

I have shown that a forge weld happens as soon as the 2 pieces touch and no other behavior is needed if done properly. 

Of course having to finish up the weld the hammer is used. But ideally the 2 pieces are welded before pressure from hammer or smack or what have you is applied.

[Frosty]

If no oxidization occurs how can there be scale to dissolve or carry out of the joint?

If you use a silicon cake pan it's easy to break the borax out and cooking off the water won't dissolve steel pans. If you like iron add some and you'll know exactly how much you have. And not to be borish repeating myself but if you bring the borax to temp slowly it doesn't foam as you drive off the water before it reaches boiling temp. This is DRY but not anhydrous.

You need to get it to 230f. to drive off the hygroscopic moisture. The moisture that's molecularly bonded. Differentiating between damp and hygroscopic is basic soils lab moisture content procedure. It's the difference between Dry and Anhydrous.  I did this thousands of times in the soils lab. 

The addition of boric acid primarily lowers the melting temp so the flux wets at a lower temperature than anhydrous borax.

Dry borax doesn't wet the joint as well because boiling off the hygroscopic moisture makes it foam and forms voids against the hot steel  can even drive the flux out of the joint leaving it dry, unprotected.

Just reread a couple previous posts and I think I see why Rashelle thought I meant grinder cuttings. I don't use a hot saw unless I absolutely have to. My main cut off saw is a band saw so the cuttings are clean (whatever I cut) metal. 

And yes, next time I'm in the shop I'm crushing up some Petersons #2 and adding a like amount of RR rail cuttings. I'll let you know how it worked for me. 

Frosty The Lucky.

[swedefiddle]

Good Morning,

Flux is not GLUE. You can make flux with the glass bottles in your recycle bin, break it up small and use a mortar/pestle to make a powder. You can also use red clay brick the same way, break it up and grind it into a powder. Easy Peasy.

Neil

[Rashelle]

I tried the belt sander leavings cause I wanted to eliminate it as a source. Unless it worked. I used band saw cuttings cause I wanted to see if it would work as a source of iron/steel to add to the mix. I was experimenting to control variables and find limits.

[Frosty]

Neil: Powdered glass is a pretty well known flux but powdered red brick? Have you used it with steel? Heck, how often do you use powdered glass welding steel?

How many folks here on Iforge forge welding regularly, flux steel joins with powdered glass? Other material, recipes, etc.? 

Only direct experience please, not hearsay. None of those, I know a guy who . . . BS.

Frosty The Lucky.

[ThomasPowers]

Not with steel; it is one of the suggested ones for real wrought iron and I have used it for that.   IIRC there is a section of "Practical Blacksmithing" where they are discussing the change from WI to "Bessemer Steel" and having to change the welding flux.  Going to borax based fluxes is mentioned rather than silica based ones.

[Donal Harris]

On 4/29/2019 at 4:35 PM, jlpservicesinc said:

Some days I am a forging and forge welding God. Other days I'm a noob even though I have made the item 2000000 gizzilion times. 
 

You are a professional and I assume you are surprised when a weld doesn’t take, even though occasionally as you said above it doesn’t. Are you surprised when it doesn’t and how many welds did you have to do before you were sure a weld was going to work before you put the pieces in the fire?

I am always shocked when it works, and each successful weld is cause for celebration.

[jlpservicesinc]

Way back when I was a full-time smith it wasn't till I really started delving into all aspect of the trade that I found I was completely limited to only a handful of items unless I could forge weld. 

Forge welding is used pretty much every time I light the forge.   

It's funny you mentioned surprised..  YES for sure. I'm amazed because everything is prepped correctly the items are at the right temps and nothing.  The difference now is, the fact I have a rather large knowledge base to draw from and then troubleshoot the reason/s why the weld did not take.  This is where many people who are newer have no answers vs frustration and failure. 

As an example when I was making the most recent hammer and the welds would not take. Turns out I had used some funky coal and once I remembered I had the same experience before with this coal, it was simply a matter of swapping it out for the stuff I normally run and that was all it took. 

The person helping me was like.  Ah, is this normal for it not to weld and I said, it can be..  The human factor is applicable all the time.  This human attribute is seen in all blacksmithing or hand made items. 
 

100% I am sure the items will weld now.   The process of them getting there coupled with doubt is where that percentage changes.  In other words. If I have everything where it should be in the fire and everything is pulled to the anvil (drop tong method) and I place the rods in the correct position in a timely fashion they will indeed be welded right off. 

If I mess up the placement or the anvil is really cold I know to hit it once. If it sticks then I'm good to go. If it does not stick right then. I simply stop and take another heat and do it again. this time paying attention to what I messed up on the weld before. 

I have had a few times that it has taken me 3 times of heating the bars to be welded before they take.   I have a tendency to work the other way around than most starting with the lower temperature range for welds vs off the high end.. 
 

 

[Rashelle]

I also tend towards low temp welding rather then the higher end. If I get to the higher end solid fuel or gas I'm more likely to burn the piece. Thus I swim in the low end. A good example is just last Saturday, I got distracted while showing the weld on a strap axe. Made a real good example of what burnt steel looks like though. As it didn't fall apart. Got promptly tossed under the forge, then started another but had someone asking questions, that one got tossed under the forge also. Third one turned out great. Luckily they got the drift of what to do on the first one, then were working on their projects when I went to do the second, rather then making them sit thru the demo again. Thus the urgent questioning where I just tossed the second under the forge. Third one went great and then demoed the spreading the bit and drifting, etc. steps.