heat's effect on steel?

Discussion in 'Shop Talk' started by buck_1one, May 7, 2006.

  1. buck_1one

    buck_1one Well-Known Member

    Nov 26, 2004
    West Virginia
    I need to do a frame repair on an old truck. The steel is 5 gage. So I'm thinking about heating the repair plate so I can bend it into the shape I need, then mig welding it back into the frame.

    I'm wondering what effect heating the steel for bending will have on it. Will it make it hard and brittle or soft and weak. Will heating have any effect on it for welding? This repair is right where the front leaf spring and bumper mount are located so the repair has to be strong and reliable.

    The truck's frame looks to have been hit pretty good at some point in its life and had some really crappy "repair" work done. Such as welding in a bolt to make up for a gap in the steel. What I'd like to do is cut out this "repair" and weld in new steel to bring it back to the way it should have been.

    I've done lots of welding and cold bending of sheetmetal, but nothing on this scale of thickness or structureal integrity.


    PS Please don't tell me to look for a replacement frame or a donor for the parts as this is not a option on this frame.
  2. agmantoo

    agmantoo agmantoo Supporter

    May 22, 2003
    Zone 7
    Fine a similar piece of frame from a donor vehicle and cut out a section. Use that to double frame the defective area by stitch welding the donor section over the damaged area.

  3. Hip_Shot_Hanna

    Hip_Shot_Hanna Well-Known Member

    Apr 2, 2005
    Personaly i would not weld a chassis , plate and bolt it together , if you have to heat it let it cool down on its own do NOT use water to cool it , it will make it brittle , old vehicle frames can be heated to realign them but the new vehlcles have to be bent back with brute force and ignorance the steel is heat treated and will fail if re heated ,
    a stick welder will give you better penetration than a mig , if you have to weld it use short welds and watch for warping or twisting of the frame , do 2 or 3 one inch welds then go for a smoke and let it cool then go back and do 3 more