Cleaning Brazed Stainless Steel/Brass Assemblies
We braze brass parts to 303 stainless rods. Because of the relatively low volume, this operation is done manually. After brazing, flux residue and smut are currently cleaned by abrasive blasting or with sandpaper. We find it time consuming and tedious. Is there a chemical treatment available that will perhaps perform faster and better without attacking the brazed joint?Bruce Croix
- Monee, Illinois, USA
Yes, there is a good way to clean the braze. A peroxide based acid formulation will clean the braze joints very well without damaging the integrity of the joint. I have done this many times with customers in the plumbing industry that need to clean and deoxidize parts prior to plating.Dan Brewer
chemical process supplier - Gurnee, Illinois
February 14, 2011
We have a similar problem with braze joints here at our aerospace facility.
Can you give me the formula for the peroxide method please Dan, and I will give it a try.
- Titchfield England
February 14, 2011
I haven't seen Dan in the forums in a long time, but I'm confident that he is speaking of a sulfuric acid plus hydrogen peroxide etch. An issue with this is that hydrogen peroxide will quickly and unaffordably decompose unless special stabilizers are included in the mix. The practical result of this is that the sulfuric peroxide etch is not a generic process formula but a proprietary product. It has been marketed for decades by Electrochemicals under the Cobra-Etch trade name. They have representation in England, and it may be that other suppliers offer a similar product these days as well. Good luck.
Ted Mooney, P.E.
Pine Beach, New Jersey
February 15, 2011
Thanks Ted, I will try to find a supplier heremike channing
- titchfield England
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