Quench only after the braze filler metal has solidified to avoid cracks or rough braze joints.
Brazing cracks in thin sheet metal.
Apply the brazing rod to the joint while continuing to heat the metal surfaces.
Heat the joint where the two pieces of metal will meet until the joint glows.
Grind the outside of the crack down to sound metal about 1 2 the thickness of the base metal.
Heat treatable or core alloys composed mainly of manganese or magnesium are also used.
If needed use clamps to secure the pieces in position.
Weld the excavation from the outside.
The filler material flows into any and all microscopic crevices in the metal and pulls the pieces together similar to a permanent velcro.
In this video im showing you the process i use to do small rust repairs where a complete panel.
You should now have a complete joint penetration weld that is as strong as the original member assuming it is low medium carbon steel.
Position the metal as desired.
Brazing is done at lower temperatures without melting the base metals.
In most cases an overlapped joint will be stronger and braze together easier than a gapped joint.
Do not quench materials with large differences in coefficients of thermal expansion to avoid cracks in the base materials and tears within the braze alloy.
Extend the excavation at least 1 2 inch beyond the visible crack tip.
Finally brazing fluxes have a tendency to cause hydrogen embrittlement in the metal adjacent to brazed joints and this can cause cracking in that metal as panels vibration cycle over miles and time.
Because of this you don t need the base metals to be similar so it s possible to tig braze copper to stainless steel as an example.
Note that quenching can affect base material mechanical properties.
Did you want to learn how to work around that and deliver a solid re.
A convenient method of preplacing filler metal is by using a brazing sheet an aluminum alloy base metal coated on one or both sides.
Braze welding unlike brazing goes beyond capillary action and deposits a strengthening thickness or bead of brazing material in braze weld.
