It is important for stainless steel to stay clean in both the factory environment and after it is delivered to the customer. Stainless steel that is dirty in the factory environment and undergoes brazing services without being cleaned can experience traces of oxidation that tarnish the surface, and lead to corrosion problems down the line. The biggest risk of oxidized parts is that the brazed joint fails to achieve a proper metallurgical bond. The oxidized surfaces inhibit the flow of braze alloy and diffusion into the base metals is not achieved. Purobrite™ achieves maximum joint strength given the materials, joint design and dimensions.
Methods for Cleaning Stainless Steel
Stainless steel is cleaned in several ways, with the option of choice depending on the type substance that must be removed. For the sake of cost savings and the quality of the metal, it is important to remove unwanted surface coatings with the proper cleaning technique. If you have stainless steel parts or assemblies that need to be cleaned, below is a list of cleaning techniques for properly removing unwanted coatings that are commonly found on stainless steel.
Fingerprints can be removed with mild soap and warm water. Applying a commercial spray polish will help prevent the metal from being remarked with fingerprints.
Oil and Grease
Oil and grease can be removed with hydrocarbon solvents such as isopropyl alcohol and acetone. Alkaline formulations such as D7 polish can also be used.
Mild, non-abrasive creams and polishes that are designed to remove mineral deposits from metal can be applied with a soft cloth. Do not use products that contain grit.
Soaking the metal in hot water with ammonia added, and then scouring the deposits with a soft nylon brush, is an excellent way to remove tough carbon deposits.
Applying a 10 percent phosphoric solution followed by an ammonia and water rinse, or an oxalic acid solution followed by a water rinse, is a good way to remove light rust.
Removing heavy rust can be accomplished with sandblasting or grinding. Once the rust is removed, it may be necessary to polish the metal to create an even surface.
Using a nylon brush or bristled brush to apply a solvent paint stripper or alkaline solution that is designed for removing paint is an excellent option. Follow the manufacturer’s instructions.
Discoloration can be treated with a non-abrasive cream or polish such as Solvol Auto Chrome Metal Polish, which is ideal for metal that has a bright, polished surface.
Need Professional Brazing Services?
If so, Franklin Brazing is the company to call. Using our proprietary PuroBrite™ brazing system to treat stainless steel, we achieve a first pass yield of over 99 percent, producing assemblies that demonstrate excellent surface quality and dimensional stability. With over 40 years experience in metallurgy, we have the experience and expertise you need in a brazing services provider. Call us today at (800) 450-7822, or click here to use our contact form.