How To Fix Your Rollcage - Wreck Repair

Using a MIG welder, Cornett welds with the wire touching the slug. The heat must be turned up high enough on the welder that it is capable of fusing both the slug along with the ends of the tubing on both sides. That's why the width of the gap is important. It must be wide enough so that the wire can reach the slug, but close enough so that both ends of the tubing get hot as well. Cornett also adds that he always begins his weld at the bottom of the tube and works his way up. This way he is always working at the edge of the weld puddle. If you start at the top and work your way down, gravity can pull the weld puddle into your work area and keep you from getting good weld penetration.

Next come the rosette welds. Hold the tip of the welder perpendicular to the hole and work your way around in a circle until the hole you have drilled into the tubing is completely filled with the weld puddle.

Cornett says when making your rosette welds not to be afraid to turn the voltage up on your welder. You have to make sure the weld really burns into the slug, but because of the wall thickness you don't have to worry about burning through. Also, Cornett says he uses his ears as much as his eyes when making his rosette welds. Once the weld puddle rises above the thickness of the outer tube the sound changes and he knows to stop.

Here's the completed weld. You can tell from the color of the metal that a lot of heat has been put into it. But it is necessary to make sure both pieces of tubing and the slug are properly fused. All weld beads should extend just beyond the diameter of the tubing. Any weld that sinks below the tubing isn't good enough.

It isn't structurally necessary, but for the sake of neatness, Cornett sands down the weld beads until they are smooth with the tubing. Just don't go crazy with a grinder here.

Obviously, there is still a lot of work to be done before this chassis will be ready to return to the racetrack, but you can see the value of stitching the down tube where we did. This particular bar extends through the firewall and ends at a multiple-joint at the A-pillar. Stitching the tubing where Cornett chose produced a repair that is just as strong as replacing the entire piece of tubing, plus it saved him a lot of time and his customer a lot of money.