Brazing Cracks In Thin Sheet Metal

Here s a few tips on repairing rust holes in car body panels.

Brazing cracks in thin sheet metal.

In this video im showing you the process i use to do small rust repairs where a complete panel. Note that quenching can affect base material mechanical properties. Braze welding unlike brazing goes beyond capillary action and deposits a strengthening thickness or bead of brazing material in braze weld. You should now have a complete joint penetration weld that is as strong as the original member assuming it is low medium carbon steel.

In most cases an overlapped joint will be stronger and braze together easier than a gapped joint. Weld the excavation from the outside. Have you ever welded something so thin and worn out that all you do is blow holes in it. A third method of applying brazing filler metal is to use a paste mixture of flux and filler metal powder.

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. Brazing is done at lower temperatures without melting the base metals. Heat the joint where the two pieces of metal will meet until the joint glows. Heat treatable or core alloys composed mainly of manganese or magnesium are also used.

Apply the brazing rod to the joint while continuing to heat the metal surfaces. Position the metal as desired. Quench only after the braze filler metal has solidified to avoid cracks or rough braze joints. The filler material flows into any and all microscopic crevices in the metal and pulls the pieces together similar to a permanent velcro.

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. 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. Did you want to learn how to work around that and deliver a solid re. Grind the outside of the crack down to sound metal about 1 2 the thickness of the base metal.