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Forge welding is an essential process in blacksmithing. It is useful for joining two pieces of metals. It involves a simple step of heating the two metal pieces to a high temperature and hammering them together. The best forge welding flux will enhance this process for a perfect result.
But blacksmiths face certain challenges with forge welding. Most processes end with scales on the surface of the materials accompanied by some other undesirable results. Welding surfaces often get oxidized; hence resulting in a poor-quality weld.
The presence of borax can prevent the surfaces from oxidizing during forge welding. It will also extract all impurities that can cause poor quality weld on the surface of the materials.
The use of flux is a long-time solution to this problem. The oldest form of flux that ancient blacksmiths use is fine silica sand. Modern blacksmiths now use borax together with some powdered iron fillings.
However, if you frequently find yourself forging a Damascus blade or forge welding several layers of metal, you will probably need a good quality forge welding flux.
There are different types and brands of flux that are suitable for forge welding. But you need to shoot for the best products if you want the best possible outcome and you want to get a high value for money.
So, what are the best fluxes for your forge welding processes?
Best Forge Welding Flux
It is a personal preference. But the advantages of using a forge welding flux are immense. In simple terms, forge welding can cause oxidation that consequently results in scales and surface irregularities.
If you prefer TIG/MIG welding, you won’t need flux. But the workpiece should be dead clean and sealed properly. Blacksmiths, on the other hand, mostly prefer forge welding as it is more reliable and can last for a hell of a long time.
Here’s the catch, forge welding requires sheer focus and top-notch skill. Forge welding is not a beginner’s game.
Scales are ugly. You don’t want your final product to have these as it portrays poor craftsmanship. If you wish to keep your crafts nice and clean, we prefer using a high-quality forge welding flux.
One of the most obvious options is borax, as it has no additives and is widely available as a laundry detergent.
Borax is no doubt a great option, but some manufactures provide specialized flux for forge welding. They can be used for high temperatures, for brazing, welding cast, and that too for a wide range of metals.
And yes, like all other items, you’d come across an ocean of different options. Not all of them are effective.
We have done the difficult part for you. Here are some of the best forge welding flux that promise to deliver high quality and better results.
- For brazing and welding cast and malleable iron and steel
- For torch welding brass, bronze and copper
- Working temperature 1200-1600F/650-870C
- AWS Brazing Classification FB3-F
- Coarser texture than Peterson #1 Fine
Why do we like it?
You’re tired of using low-quality flux that lets scales build-up, right? No worries! The Peterson flux is very reliable and effective. Apart from avoiding scale formation, this flux also facilitates in creating a stronger weld.
This flux also helps in extracting other impurities from the metal. The working temperature of the Peterson flux ranges from 1200 °F to 1600 °F.
Suitable For Various Materials
It is an excellent option for brazing steel, malleable and cast iron welding brass, copper, and bronze. Brazing is a popular metal-joining procedure in which several metal items are joined together by melting and flowing a filler material in the conjunction point.
How does this flux help in brazing? It mixes with oxides that are formed during the process and lowers their viscosity and melting points. When the metal layers/pieces are hammered together, these low viscosity oxides flow out of the joint.
Additional Information
Peterson flux also comes with AWS Brazing Classification FB3-F, meaning that it is in blue powder form and works with BAg and BCup (phos-copper-silver alloy) filler metals. Also, it is a general-purpose flux that is suitable for most of the ferrous and non-ferrous alloys.
This product can also be used to braze carbides, ferrous, and non-ferrous metals. Typically, this flux constitutes of borates and fluorides.
Still wondering why this is our top pick? Peterson fluxes are the #1 selling brand in the brazing flux category on Amazon. With several satisfied users, this flux has become Amazon’s choice product.
Easy To Use
Furthermore, the flux is very easy to use. You just have to dip in the brazing rod and VOILA! The flux will adhere to it. If you keep on applying more heat, the powder will start to melt.
To remove the excess flux residue, you can just apply hot water to the specified area.
Users have used this flux to successfully forge weld 1095 steel (carbon content 0.90-1.03%) and 1075 (carbon content 0.70-0.80 %).
If you want to avoid scales, improve the fusion of metals, and resultantly obtain finer crafts, this flux should be your way to go.
Here are some of the pros and cons of this product.
Pros
A blue powder flux with a temperature range of 1200 °F-1600 °F.
AWS Brazing Classification FB3-F.
Easy to use.
Perfect for brazing.
Cons
Not suitable for high-temperature forge welds.
Pricey, but more effective
The Stableweld forge welding flux by Anti-Borax is one of the more premium options. It is a tan powder with grey chips that offers a lower (12%) metal loading than its predecessor.
Why do we like it?
This forge welding flux has managed to land the second spot on our list. Forge welding is indeed an arduous task, but having the right forge welding flux can make it a lot easier.
You might have observed that scales caused by oxidation are difficult to remove. You probably need a wire/block brush to get rid of them.
Prevention is better than cure, right? So, why not use a good quality flux to avoid such instances?
Efficient and Effective
The Stableweld forge welding flux from Anti-Borax is one of the most effective and reliable fluxes out there. It is a metal-bearing high-grade forge welding flux that can easily operate at high temperatures.
It is basically a tan powder with grey chips with less than 0.5% volatile content. Unlike our top pick, this powdered flux does not have fluorides; rather, it contains the good old flux agent silica powder.
Quick Note
Due to the inorganic borates, toxic fumes might be released when the powder comes in contact with high-temperature metal stocks. It is recommended to have proper exhaust ventilation in your workshop. Wearing a NIOSH approved respirator is even better.
This forge borax compound flux constitutes of 90-99% anhydrous borax with a considerable amount of steel chips, slag, borax acid, and silica.
The melting point for this product is 1382 °F, making it an excellent choice for forge welding. The flux is also non-carcinogenic. This flux has a lower metal loading compared to the manufacturer’s other product, Anti-Borax EZ flux.
The Stableweld flux is perfect for applications that require lower metal concentration in flux.
Before we move on, here are some of the pros and cons of this flux.
Pros
An ideal flux for forge welding and farrier applications.
A shelf life of two years.
Non-carcinogenic.
Easy to clean.
Cons
Expensive.
- welding flux
Why do we like it?
Even if you use a flux, you can end up with some nasty scales that are hard to remove. The Anvil Iron Mountain forge welding flux is indeed a bit expensive compared to all other fluxes, but the first-class quality and ability to produce durable welds make it a worthy purchase.
The manufacturer focuses explicitly on its effectiveness in coal, coke, and gas forges. Being made in the USA, it is one of the most premium fluxes on the market.
Functional Ingredients
This forge welding flux contains Disodiumtetraborate (NA2B4O2) and pure iron powder (Fe). It is not your ordinary traditional forge welding flux.
And another great thing about this flux is that when you’re done with forge welding, you can easily get rid of the residue flux.
The 16 oz. package is not the biggest on the market but will surely last for some time. Make sure the cap is tightly secured when it’s not being used. The flux container should also be stored in a dry place.
Pro Tip
For improved efficiency, scarf the metals to be joined, and use a block/wire brush to remove the existing scales. Apply flux when the metals are red hot and reheat them until the flux gives out a glossy look.
Nonetheless, this is a great flux from a renowned manufacturer, Iron Mountain Blacksmith Products.
It is a big-budget flux but will surely improve the look and strength of your welds.
Pros
Made in the USA.
Premium quality.
Cons
Expensive.
- Use with low fuming bronze rod
- 1,400 to 2,200 degrees Fahrenheit active temperature range
Why do we like it?
The US forge 2350 brazing flux is excellent in terms of a high-temperature range and solid welds. The manufacturer is famous for various blacksmithing & welding equipment and has been in the industry for years.
The flux is shipped in an 8 oz. container. The container is not as big as other products on this list, but for the low-price, it is definitely a great deal.
The manufacturer recommends using this flux with a low fuming bronze rod as it’ll be more effective. You just have to dip the rod into the flux container and transfer it to the weld area.
Pro Tip
Make sure the rod is hot enough. After applying the flux, reheat the weld and wait for the flux to turn glossy. The flux can be used with the low fuming bronze rod for several ferrous and non-ferrous metals.
Us Forge 2350 brazing flux is designed to work within 1400°F-2200 °F temperature range. Having such a whacking temperature range, this flux can also be used for forge welding.
Worried about the residual flux? You can use your good old chipping hammer to get rid of it.
All in all, this is a great option for people looking for something cheap, but effective.
Pros
1400-2200 °F active temperature range.
Great for brazing.
Cons
Small quantity.
The research
Are brazing and forge welding the same? Can the same flux be used for both?
How can you get rid of residual flux?
How do I apply flux to welding surfaces?
Can I use charcoal as fuel during forging?
Is forge welding strong enough for metals?
Does forge welding require hammering?
Is Borax and baking soda the same thing?
Can I learn how to use flux online?
Can flux cause a fire outbreak?
Do I need flux for cold forging?
Does forge welding without flux expose me to risks?
Can you make flux in the blacksmith shop?
Who should get this?
Flux is handy for avoiding oxidation, scales formation, and solid welds. Anyone who frequently joins metals using brazing and forge welding should get a high-grade flux.
You can work without flux in some cases, but the efficiency and strength of your welds might not be the same.
Why should you trust us?
We are experienced in blacksmithing, welding, and metalworking tools. Our team carefully evaluates the pros and cons of each product before listing them on our lists.
Forge welding fluxes are a crucial part of creating something unique and attractive. Having several industry experts and advisors on board, we always choose the best products in each niche.
How we picked?
Following are some of the factors we considered while compiling this list:
- Temperature Range: Welding fluxes are supposed to work in a specific temperature range. Our priority was to include only those fluxes that can work at high temperatures as forge welding requires ridiculously high temperatures.
- Cost: Nobody wants to spend a fortune on buying a welding flux. Even the most expensive fluxes on this list are pretty affordable. Furthermore, our team always filters out those products that provide the right balance between price and performance.
- Container capacity: You don’t want the flux to run out on the first day, right? We have included only those fluxes that come in a fairly large container. Brazing rods can easily be dipped in them.
How we tested?
Our journey started with going through tons of customer reviews on different products. Throughout the process, we closely examined the pros and cons of each flux by comparing their temperature ranges, cost, and container capacity.
Furthermore, we asked our team to put some of the fluxes to use. Doing this, we were able to identify the best forge welding fluxes along with the advantages and downsides of each.
Care and maintenance tips
The flux itself should be stored in a dry environment. The scarf should be cleaned properly using a wire brush to remove existing scales. If you’re working with a gas forge, it is recommended you cover the firebricks with scrap metal as melting flux can hurt the bricks.
Are brazing and forge welding the same? Can the same flux be used for both?
In brazing, the metal pieces are joined by flowing a filler metal in between. Forge welding, on the other hand, joins metals by fusion.
The same flux can be used only if the temperature range accommodates both the processes.
How to apply flux?
You just have to dip the rod into the flux container, reheat the rod in the forge, and finally, wait for the flux to give out a glossy look.
How can you get rid of residual flux?
If you’re using a high-quality flux, getting rid of residual flux won’t be an issue. You can use a typical chipping hammer to remove it.
Do you need flux to weld?
You can weld without a flux, but you risk getting undesirable results. The flux will not only make the welding process easier for you. It will also enhance your productivity and improve the outcome.
Flux will help extract all the impurities on the materials’ surface that might interfere with the welding process. It will also prevent the welding process from oxidizing during the forging process.
Can I use Borax as flux?
Yes! Borax is one of the most valuable materials that can act as flux without any hassle. Blacksmiths often mix it with iron filings to enhance its performance. It enables high-quality weld by working as a cleaning and purifying agent for the welding surface.
How do I apply flux to welding surfaces?
There are two ways to apply any flux to welding surfaces. The first way is by sprinkling the flux on the welding surface. Ensure that the flux covers the entire body when you spread.
The alternative method is submerging the welding surface into a large container of flux. This method is most suitable for small metal pieces that can fit into a sizable container.
All you need to do is to immerse the welding surfaces in the container once you finish heating. Ensure that the flux covers up every part of the surface.
Which metal cannot be forged?
Blacksmiths can forge most metals and irons, except cast irons. Cast irons usually have more than 2% of carbon content. Hence, they typically have a low melting point, and they are quite brittle.
These features make it unfit for forging and most other blacksmithing processes.
Can I use charcoal as fuel during forging?
Yes, you can use charcoal as fuel in your regular forge. Charcoal is an efficient fuel for forging because it contains more carbon than wood. It will burn longer and hotter than wood, and it can stand shoulder to shoulder with other coal fuels.
Is forge welding strong enough for metals?
Forge welding is a joining technique. It is suitable for both high and low carbon steels.
Forge welding is one of the best ways to join metals. The two metal pieces form a solid-state fusion with each other when they are liquefied.
Where can I buy flux?
Flux is not a scarce commodity, and they are available in various retail outlets and stores that sell blacksmithing materials. You can buy online directly from various manufacturers or different e-commerce websites.
Most of these online options offer shipping and delivery. So, they can help you beat the hassle of distance and barrier posed by the traditional market.
Does forge welding require hammering?
Yes! Hammering is one of the core steps of forge welding. After heating the two metal pieces that you intend to join, you have to hammer them together.
The hammering will ensure proper solid-state fusion between the two metals.
Is Borax and baking soda the same thing?
No! Borax and baking soda are entirely different from each other, both in chemical composition. Although they are useful in household cleaning processes, they cannot serve the same purpose for blacksmiths.
Borax can work as a flux for forge welding processes, but baking soda cannot work in this capacity.
Can I learn how to use flux online?
The internet is an ocean of endless knowledge, waiting for exploration. Like many other skills and processes, you can learn how to use Borax online.
You can read through various helpful websites or read different valuable pdf materials available online.
You can also explore related YouTube videos that teach how to use flux for forge welding. But you must ensure that the learning materials you get online are from reputable authors and sources.
Is flux a solid substance?
No, fluxes are not solid. They are fine granulated powders.
Can flux cause a fire outbreak?
There is no established link between flux and fire outbreaks. So, it is safe to say flux will not trigger or aggravate fire outbreaks.
Do I need flux for cold forging?
You don’t need a flux for cold forging. Cold forging is another technique that does not require heat and much hammering. So, it does not need borax because the surface is not at risk of oxidation during the forging process.
Besides, cold forging is not an ideal way to join metal pieces.
Does forge welding without flux expose me to risks?
No! Forging with or without borax has little or nothing to do with safety. The essence of using flux during forge welding is to improve the weld’s quality by mitigating oxidation and purifying welding surfaces.
Can you make flux in the blacksmith shop?
You might not be able to make professional flux in the blacksmith shop. But you can improvise by using borax and powdered iron fillings. You can also simulate the ancient blacksmiths by using fine silica sand.
Conclusion
Contemporary blacksmithing is all about precision and attractiveness. If your metal craft is not appealing eye candy to the buyer, game over for you. Using a good quality flux can make the welds a lot stronger and that too, without scale formation.
All of these products have been carefully picked, and each one of them promises good value and performance. Before diving in blindly, we recommend you assess your needs and budget.
