Ability of molten braze or solder to spread over and bond to the base metal instead of balling up. It requires an oxide-free surface, provided by flux, protective atmosphere or vacuum, plus the right temperature. A low contact angle and a smooth, concave fillet show good wetting; filler beading up like water on wax shows poor cleaning, the wrong flux or underheating.
Alloy's balling up and not wetting, the fitting's still oxidized, clean it and use more flux.
Also heard as
- wet
- wet out
Related terms
Brazing
Joining metals with a filler melting above 450 °C but below the base metals, drawn in by capillary action.
Soldering
Joining with a filler metal that melts below 450 °C, wetting the parts without melting them.
Flux
Material that shields molten metal from air and cleans oxides, as rod coating, wire core, granules or paste.
Joint clearance
The gap between mating parts in a brazed or soldered joint, which controls capillary flow and strength.