Drag Cage Questions

[Gusmann]

Andy,

I will be helping a friend install a roll cage in his 1993 Mustang coupe. We have a few questions about the welding of the cage (mild steel). We will be using .030” ER70-S6 and an AutoArc (Miller) 170 Amp machine.

As this is a coupe, there will be no easy way to reinstall the headliner if it is removed before welding. How can we protect the headliner while leaving it in the car during welding? I have heard of people using wet cardboard and aluminum sheets.

I want the beads to look nice. I’m sure I’ll be able to weld attractive beads in this amperage range, but I’m a little worried that the bead may start a little high and rope like before the joint gets hot. Would it be worthwhile to preheat the joint with a propane torch, and how warm should we get it?

The roll cage is a factory built/notched unit. After hours of work, it fits well and can hardly be seen from out side the car. The only problem is how do I weld in the tight areas (near the windshield and where the rear bars attach to the main hoop)? The only option we see is hole-sawing holes into the floor, so we can drop the cage 3”-5”. Any other tips you can offer?

Regards,

Gus

[10secBu]

To weld the front roof/windshield bar to the roof line bars, first weld the bottom half of the bar on both sides. Next, break your tacks loose where the roof line bars attach to the main hoop and forward part of the floor and let the assembly lay down on the floor, finish welding the top side of the roof/windhshield bar.

To weld the rear support bars to the main hoop, you may be able to get the torch around either side and meet at the top if the down bars have a steep enough angle on them. If not, then do as the front bars by welding the bottom half, then break the main hoop and rear bars loose from the floor and finish welding. Once this is done, the partial welded assemblies can be put back into position and finish welded together.

Be careful how you weld not to distort the way the parts come together...if you did 3 or so good strong tacks per bar, they shouldn't move much, if at all.

For your welder settings...they best I can recommend is to take some scrap and practice your hand movements as well as your voltage/wire speed settings...170 amps should be able to weld your cage assuming your not limiting it't power input by using a too small gauge extension cord assuming your using one at all.

Only weld on the cage after your satisfied with the practice pieces and how the weld beads are penetrating...maybe cut a few apart to see how deep your penetrating.

As always with a cage...safety has to come first.

[home05]

The Headliner

In regards for the headliner, you can use 1 or more welding blankets. I find these very useful, I can hardly blacken them by welding on top of them. Get a few blankets for yourself and cover all of the headliner.

Patrick

[ASKANDY]

All great answers!

Nice seeing you at the show Gus.

A