Nicrobraz Stop-Off Green

From the outset of its design, the purpose of Green Stop Off was to ensure it had broad adaptability. It can be used in the brazing processes of almost all parent metals (except for metals that react with it, such as titanium and zirconium). There are no specific requirements for the type of brazing, as it can be applied in the brazing processes of various filler metals. It is currently the best brazing stop-off material, providing technical support to protect metal surfaces where the brazing filler cannot reach during the brazing process, thereby providing optimal brazing protection. By restricting the brazing filler to only remain in the brazing gaps, it can effectively reduce the amount of filler used. Apart from this, its main function is to protect areas that don't need to be brazed during the brazing process. When using flame spraying of metal coatings, it's often used to shield related areas from being covered.

In general high-temperature vacuum brazing, the use of Nicrobraz Green Stop Off will not contaminate the gas in the vacuum furnace. It mainly comes in the following types:

Type 1 Liquid (Solvent-based) The viscosity of Green Stop Off can be adjusted using thinners or acetone. It is usually applied with a brush, ensuring accurate placement and controlling the amount used. If adjusted to the appropriate viscosity, it can also be applied via screen printing, spraying, impregnating, etc. Regardless of the method, care is needed during application to prevent contaminating the brazing gaps. As described above, Nicrobraz Green Stop Off acts as an effective brazing stop-off to prevent indiscriminate spread of brazing filler during the brazing process. When the filler is liquid during the brazing process (as in flame brazing), the stop-off layer should be wider, while the filler should be relatively narrower. Using excessive filler can affect the stop-off effect of the stop-off agent. (When using liquid filler, it is best to use YELLOW Stop Off).

Type 2 (Water-based) Its usage and form are almost exactly the same as Type 1. The difference is that Type 2 is water-based, doesn't require frequent stirring, has better coverage, is odorless, and is non-flammable.

There's another version of Green Stop Off Type 1 called the Stop-Off Pen. Its usage is quite straightforward. Just drawing with the pen can effectively prevent molten brazing filler from overflowing. It can be used on any metal surface as a heat-resistant mark. This mark won't disappear until the temperature reaches 1650ﾰC.

Removal Procedure: After brazing, if there's residue of the stop-off agent on the brazing surface, it doesn't affect the brazing joint. This residue can be removed by: 1) Vacuum blasting 2) Steel shot blasting 3) Cleaning with a steel brush 4) Polishing (as with marble statues, copper plates, etc.) 5) Heating a solution containing 10% nitric acid and 2% hydrofluoric acid to 65ﾰC.

Suggested Usage: Use Nicrobraz green stop off to prevent molten brazing filler from flowing into lines, holes, and surfaces of castings. It can be used on various parent metal materials, whether ferrous or non-ferrous. Except in metals containing titanium and zirconium (for those, use orange or blue stop off). Green stop off is suitable as a brazing stop-off agent for any brazing filler, including nickel-based, copper-based, silver-based, and more.