Frame straightening can be complicated and can require special equipment. Only trained personnel can straighten frames.
Make a complete analysis of the condition of the frame before taking any steps to straighten the frame. Analyze the cause of the failure. This will determine the correct sequence of steps in the repair. Refer to Frame Conditions - Sag or Frame Conditions - Buckle or Frame Conditions - Sidesway or Frame Conditions - Diamond or Frame Conditions - Twist . Use corrective procedures in order to reverse the flow of the damaging forces. Apply pressure from different directions at the same time in order to reverse the flow of forces. Avoid the following uses of heat:
| • | Too much |
| • | Too little |
| • | The improper application |
Use a large size multi-hole heating tip and a neutral flame in order to heat the frame. Heat the area of the frame you want to stretch. In a neutral flame, the oxygen adjust opens just enough in order to remove the feathers or the stringers from the blue center at the tip of the torch. Heat the area after you exert sufficient pressure in order to cause a slight checking, or silvery cracks to appear on the surface of the metal. Gradually increase the pressure while heating. Do not heat the frame beyond 606°C (1200°F). A red glow indicates that the material is overheated. Overheating will cause distortion and stretching, as well as a change in the characteristics of the metal.
