Technical

Braze alloy in the form of tape is primarily intended to be used for honeycomb brazing.  The honeycomb segments of rings may be supplied with the tape pre-applied or the end user may apply the tape themselves.  This advice sheet will offer advice and tips to get the best results from brazing with braze tape.

Storage:  Pre-applied braze tape: Store the honeycomb segments or rings in the sealed bags to prevent the alloy from drying out.  Ideally this should be in a climate-controlled environment.

Rolls of braze tape: Store in sealed bags to prevent the alloy from drying out.  A refrigerator is often used to maintain a constant temperature and humidity.

How to use: When honeycomb segments or rings are supplied with the braze tape pre-applied there is very little to do other than to inspect it  to ensure there is braze tape in every cell and then apply to the substrate and put through the appropriate braze cycle.

When applying the braze tape to a honeycomb segment a press or roller may be used to push the tape into the cells.  This may need several passes to ensure it is pushed in to the full depth.  It can be done in several passes across the width for larger sections of honeycomb if it becomes difficult to press it in.  When a greater thickness of tape is required, a second layer of tape may be applied in the same way.  Note:  It is not essential to have an exactly uniform thickness of honeycomb across the whole area as the braze alloy will melt and then wet and flow to give a uniformly distributed braze joint. Taking this into account a small degree of overlap of layers of braze tape is not a problem.

What thickness braze tape to use: The optimum thickness of the braze tape depends on the cell size, the cell depth and the amount of post braze machining to be carried out.  Please contact VBC Group to get the best advice.

Dos and Don’ts:

• Do wear nitrile gloves when handling the tape and any components to be brazed to minimize risks of contamination
• Don’t remove the protective backing tape from the braze tape until it is ready to use. This will prevent the braze tape from drying out.

Hints and Tips: Heat the braze tape with a hot air gun to about 50°C before applying it with a press/roller.  This will make it softer and easier to apply.

Alternative Uses: Braze tape may be used in other applications where it is necessary to cover a large area with a layer of braze alloy.  Braze tape may be supplied with an adhesive backing which is suitable for holding the tape in place on flat or gently angled surfaces.  Please contact VBC Group for advice on specific applications.

Alternative Products: Braze powder may also be used for honeycomb brazing, though braze tape is the preferred method.  It can be dispensed with a “pepper pot” or using an automated powder dispenser.  A spray lacquer can be used to hold powder in place.

Dimensions: Braze Tape is available in widths of up to 300mm/12”, thicknesses from 0.1mm to 2.0mm.  The binder content is in the region of 6% and a range of powder particle sizes are available to suit the requirements of the application.