This week’s Welding Talk is about MIG and TIG brazing. Maybe you’re new to metalworking and believe brazing’s right for your first project? Or perhaps you’re an experienced welder facing the challenge of brazing for the first time? Either way, pour yourself a tea or coffee and grab a biscuit as we get you up to speed with the basics…
First off, brazing is just a variation on full-blown TIG or MIG welding. It’s nothing to be frightened of. Brazing has been around for centuries and uses heat to bond metal with suitable non-ferrous filler rather than fusing it by melting as you do when welding.
Powerful and versatile
TIG brazing and MIG brazing simply bring this proven process up to date with modern MIG and TIG welding equipment. You’ll find a wide range of machines, accessories and consumables on our website. Electric brazing, as it’s also sometimes called, is powerful, versatile and enables metal joining in situations where welding isn’t appropriate. It’s a great addition to your metalworking skill set.
Benefits of electric brazing
Let’s start with the benefits of brazing over welding, then we’ll look at differences between TIG brazing and MIG brazing.
The advantages and benefits of TIG and MIG brazing come from the lower temperatures used compared with welding. Think of them as processes that work by bonding metal rather than melting it and fusing it together in a weld pool. Because of this, brazing offers useful advantages and benefits, including these:
- Weld dissimilar materials
- Reduced risk of metal deformation
- Achieve visually pleasing finishes
- Simplify joining thin sheet metal
- Save time with fast material deposition
Differences between TIG and MIG brazing?
TIG brazing is arguably simpler because it doesn’t need MIG’s more complex feed-roller and supply-line liner set-up. It’s also suited to a wider range of materials, including non-ferrous metals such as bronze, brass and copper. In many ways they’re similar to their welding equivalents.
At its heart, TIG brazing is really just about the specialised non-ferrous TIG brazing rod (typically silicone copper such as Sifsilcopper No 968) or silicone bronze (Sifphosphor Bronze No 8 or Sifalbronze No 32) that you’ll use, depending on your project. It’s a DC-negative (or AC) process. With that in mind and the correct rod in your hand, TIG brazing is about applying good TIG technique to immaculately-clean parent materials. As ever cleanliness and material preparation are vital. Trust us; the quality of your brazing will reward time spent on this.
With MIG brazing, along with a DC+ torch electrode you’ll note the added complexity of wire feed rollers, the liner of your MIG torch’s supply line and the importance of correctly selecting suitable silicone bronze MIG wire. Start with something like Sif Silicone Bronze MIG 8 or ask us for advice. You’ll need the right gas too. From experience we recommend that you only use pure argon for MIG brazing.
Your choice of supply-line liner is important for any MIG work – but particularly so for MIG brazing. For best results we recommend a good quality Teflon liner, along with the use of U-grooved wire feed rollers, to complement the softer silicone bronze MIG wire you’ll use. It’s important to minimise the possibility of wire-feed problems such as ‘bird nesting’and both of these will help. Best of all, consider getting a decent spool-on-gun MIG torch. Once an expensive tool for intensive professional use, spool-on-gun torches are now so affordable that they’re a good investment for all welders and brazers.
Set-up and brazing technique
As ever, machine and torch set-up matters for TIG and MIG brazing – particularly for the latter because of all the variables involved in achieving a good result.
Having a good welding machine is a great starting point (look at our MIG 180, MIG 250 or MIG MTS 250 machines). So’s looking after it well. Both will help ensure that your machine looks after you too! Thirdly, invest time in correct set-up. A bit of time spent on set-up and preparation before starting work will reward you with a faster, better-quality result.
With TIG brazing, you use standard TIG technique. However, you will not be looking for the pool; remember that we are heating, not melting the parent metal. For MIG, it’s similar to MIG dip transfer technique, but with no pool present other than the material being added. Either way, because you’re bonding metal, not just filling-and-fusing it, do make sure your joints are nice and close before brazing. We’re back to accurate prep again…
Unbiased professional advice always helps
As with all welding and brazing, you can grasp the basics quickly, but mastery takes years of training, knowledge transfer, experience and that ever-important practice. Whether you’re MIG brazing for the first time in your home workshop, or tackling advanced vehicle panel work with manganese boron steels, we can help.
Any questions? Speak with an expert
Got a question about TIG and MIG brazing machines, consumables, accessories or technique? After decades in the business, we know welding and brazing inside out. We’re always here for you with valuable honest advice about products and techniques to suit your project, brazing process and material.
Send us an email or call us sometime!