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Cleaning Stainless Steel Welds Quickly and Safely: Passivation of Stainless Steel Welds Using Ensitech TIG Brush

Cleaning Stainless Steel Welds Quickly and Safely: Passivation of Stainless Steel Welds Using Ensitech TIG Brush

Feb 8th 2018

If you've ever welded stainless steel, you know that heat tint is a very common occurrence. Heat tint appears as a discoloration and can take on a stunning "rainbow" appearance, as shown in these photos. 

The discoloration that you see is actually an oxide layer whose color is related to the temperature reached during the welding process -- the darker the color, the higher the associated temperature.

Heat tint can give your finished product a beautiful appearance, and this can be left as-is if a certain appearance is what you're going for. So why is cleaning stainless steel welds important? If heat tint is not removed from the finished product, and the protective layer restored through passivation, it can make the surface more vulnerable to corrosion. For this reason, a number of methods have been developed to remove the compromising oxidized layer from the welded fabrication.

Pickling Paste: The Old Standby

Pickling paste has long been a standard way to remove heat tint from stainless steel welds. The paste, made from hydrofluoric acid and nitric acid, is applied to the affected areas using a brush or spray, then later removed and neutralized with a neutralizing agent. As a final step, a passivation agent is often applied; the purpose of this step is to create an invisible surface film that makes the object less susceptible to harsh environments.

While pickling paste is an old standby for cleaning stainless steel welds, it does have some major drawbacks. Application can be slow; the entire process requires multiple steps; and the chemicals that make up pickling paste are hazardous to humans (requiring extensive personal protective equipment) and also to any surface they might come in contact with.

(By the way, we do know that pickling paste doesn't have anything to do with pickles. Just having a bit of fun with the name.)

If these drawbacks are a major concern to you, as they are to many hobbyists and businesses, you may want to consider a different approach to removing heat tint from your stainless steel welded fabrications. 

Increased Safety and Efficiency with TIG Brush by Ensitech

Ensitech, an Austrlian-owned company established in 2006, has developed the  TIG Brush Stainless Steel Weld Cleaning System. The TIG Brush system provides a safe, efficient, and cost-saving alternative to dangerous methods such as pickling paste.

TIG Brush by Ensitech Weld Finishing System

Ensitech has developed a number of TIG Brush kits which are suitable for various purposes (all the way from light duty to industrial), and they all work by combining heat, electricity, and chemistry to remove the heat tint from welds quickly and safely while also leaving the stainless surface in a fully passivated state. The TIG Brush's properietary electro-chemical process, patented power supply, and unique brush design allow the user to perform fast, high-quality cleaning of all stainless steel grades and thicknesses.

The TIG Brush Doesn't Just Clean -- It Passivates

After a stainless steel surface has been disturbed (due to welding, abrasion, or contamination), the naturally occurring protective oxide layer is compromised, which allows contaminants to reach the stainless steel. This sets in motion a self-perpetuating process of corrosion -- in other words, a welded stainless steel surface will be vulnerable to corrosion if the protective oxide layer is not restored. Restoration of this protective oxide layer is called passivation.

To accomplish passivation, the traditional pickling process requires a two-step process, "pickle and passivate." In contrast,  the TIG Brush system accomplishes both restoration of appearance and passivation of stainless steel welds in one step. In fact, extensive laboratory testing has confirmed that Ensitech’s weld cleaning process passivates stainless steels in accordance with ASTM international standards ASTM A967-05 &ASTM B912-02.

The TIG Brush system uses chelates in its proprietary Ensitech fluid to remove corrosive oxides from the stainless steel surface and enable their removal via dissolution. The use of chelates rather than harsh acids contributes to the overall safety and ease of use of the TIG Brush.

Using the TIG Brush is Simple, Safe, and Fast

As with any project, the first step is to prepare yourself with the necessary protective equipment. When using the TIG Brush, this is an easy step because the TIG Brush fluids are relatively mild and have a low toxicity. Therefore, the only PPE that's required is lightweight nitrile or latex gloves and safety glasses. That's it!

TIG Brush fluids are relatively mild and have a low toxicity

The conventional pickling process uses very harsh chemicals and requires considerable safety equipment such as a full face shield, acid-resistant garments, respiratory protection, and more. In this regard, the TIG Brush provides a major safety and efficiency advantage over the pickling process; the importance of this difference cannot be overstated.

Once your PPE is in place, choose the proper settings on the power unit and set up your workspace according to instructions. Ensitech has a number of TIG Brush training videos, such as this one, that will help you get up and running:

After your work station is set up, dip the TIG Brush into the cleaning solution. Wet the entire brush, and tap off any excess when you're done.

Now you're ready to brush the affected surface of your weld. The key is to use a light touch and circular strokes. This will get the job done and prolong the life of your brush as well.

The final step is to rinse with water and wipe clean.

Tricky corners and deep crevices can be time-consuming to clean and passivatate, but the TIG Brush also works well on these applications.

In addition, the TIG Brush system is compact and lightweight, which allows you to get more done with less effort.

Shop Weldfabulous for TIG Brush Kits, Accessories, and Fluids

Weldfabulous is proud to be an authorized Ensitech distributor for the  TIG Brush and we invite you to check out the TBE-440 Standard Kit for Weld Finishing, which offers an entry-level price point and fast, safe, and effective weld cleaning results.

The Ensitech TBE-440 Standard Kit for Weld Finishing is available from

Also browse a variety of  Ensitech TIG Brush cleaning fluids that cover your weld finishing process from start to finish.

If you need TIG Brush replacement parts or accessories, check out our selection of brush tips, cables, and more. 

Ensitech TIG Brush Accessories Replacement Brushes

TIG Brush replacement brushes are available through Weldfabulous