How should you prepare parts before loading them into a vacuum brazing furnace?

Preparing parts for a vacuum brazing furnace starts with thorough cleaning to remove oils, grease, oxides, and dirt-any residue prevents filler metal from wetting properly. Use vapor degreasing, alkaline washing, or ultrasonic cleaning followed by a deionized water rinse and hot-air drying. For aluminum, chemical etching or brushing removes the natural oxide layer just before assembly. Assemble components with filler metal pre-placed as wire, foil, or paste in joints-gaps should be 0.05–0.15 mm for capillary action. Fixturing holds everything in place during heating-use stainless steel or graphite jigs that won't react or outgas. (vacuum brazing furnace) runs best when parts are dry and free of volatiles-avoid plastic gloves that leave residues. Load the furnace carefully to prevent tipping or shifting. Pump down slowly to avoid turbulence that could displace filler. A leak check before ramp-up confirms chamber integrity. Proper prep cuts defects like voids or weak joints and keeps cycle times predictable.