How to Build and Weld a Roll Cage [Race Car Fabrication]

Last Updated on May 2022

Do you know what a roll cage is? It’s a specially-designed tubular frame that’s constructed around or inside the cab of a vehicle to offer protection to the car occupants from chances of getting injured in case of a rollover or an accident. A normal thing in stunt vehicles and race cars, roll cages are made of steel tubing and feature a geometric construction to add strength and firmness.

If you own a project car or specialize in autobody work, more so one that you wish to move to the track, you should consider installing some roll protection in it. Many forks, however, don’t even understand the benefits of installing a cage or a rolling bar. They move an extra step further beyond offering safety during a rollover.

Do you want to know how to build and weld a roll cage for your car? If yes, here is the step-by-step guide and the tips on what to do.

Have a look!

Tools

  • 1 3/4 – inch DOM steel tubing (must be mild)
  • Metal pipe cutter
  • Tape measure
  • Tube bender
  • Tube notcher
  • Carpenters angle finder or a protractor
  • Hand grinder
  • TIG or MIG welder

Step-By-Step guide

1. Start by Making a Room

Make sure you take out the vehicle’s carpet and seats, to assist you to have access to the plain metal floor. Seats and carpets also get along the way and create a fire hazard.  You can choose to take the headliner out as well, but it might be impossible to replace It after installing the roll bar.

2. Next, Size Up the Ride

Having created a room inside your vehicle, the next thing to do is measuring the vehicle’s interior dimensions to check the quantity of tubing you’ll require. Make sure you measure the distance from the ceiling down to the floor, from the front firewall to the car’s rear seats plus the width of the inner side of the car. Before making an actual purchase of the tubing, make sure you consider the thickness and the width of the material.

In case you’ll use the car for racing, most sanctioning bodies govern the dimension depending on the weight of the vehicle. A nice kick-off point is a 1 3/4 –inch round tube having up to 1.120-inch wall thickness.

3. The Base Plates

In general, the toughest part when constructing your car’s roll cage is when fixing the mounting plates made of steel on the vehicle. The stands of the roll cage fix themselves on the pates. Therefore, it’s essential to get them correctly. You wish to use big base plates (around 1/8-inch thick and 36 square inches) to distribute your load equally.

The plate placement at this time will depend on you, but basically, you wish the rear ones to be located at the back of the front seats on both sides of the car’s surface. The front ones will naturally attach to the floor of the car where the front firewall connects.

4. Contour The Base Plates

Vehicle floors are ribbed to offer strength, therefore, you must start by bending the base plates to allow you to match this shape. No gaps should be seen between the floor and the base plates. There’s a wide range of methods you can use to shape stiff steel plates. They can be hammered simply using a vise or anvil, or simply apply little heat when needed.

5. Weld in the Base Plates

Much time should be taken on these plates as they are essential. But you must take many precautions while doing the welding process since the base plate can be thicker compared to the sheet metal that you are working on too. You can easily burn your car’s floor if you are not careful. However, if you are new to welding, there’s no harm in finding an expert to carry out this step for you.

6. Now Bend the Main Hoop

Many people don’t understand what the main hoop is. It’s an extended piece of tube that you can bend to form a U-shape and it’s welded to the rear base. You are considering the two 90-degree bends close to the ceiling of your car. Immediately you finish bending it and cut it to properly fit. Here, make sure you take a little longer to begin cutting. But you can as well trim, then tack it to the base plates behind. Ensure its square and plumb to your car.

7. Take Rough Measurements for the Supporting Bars

There are many options sold out there used in supporting these bars. You can just use an extended tube that moves directly from the upper side of the main hoop to the base plates located on the front side. (there’s always one on every side of the car).

You can as well use a curved pipe that moves forward from the main hoop on the ceiling of the car and then follows pillar A at the base.

Each of them comes with a different length. To find a rough estimate of the distance, you can use the lengths of the strings. Once more, err on the extended part then cut it to fit.

8. “Fish Mouth” A Single Section of the Holding Bars

The front base plates shall be anchored with one side of the holding bars. The remaining side shall be welded on the hoop. However, to create this joint, you can either use a grinder or a tubing notcher to contour the end parts of the bar to ensure it fits on the main hoop. Even though this will consume much of your time, be sure to get it right. Then tack weld the supporting bars.

9. Final Welding

Now you are almost there. Once you are sure that all the bars are in the right position, finish weld the entire joint. We hope that you’ve created enough space between the ceiling and the main hoop to weld throughout the joints. Many sanctioning bodies always inspect for this crucial step.

In case you have welds close to the interior panels or the headliner, please use non-flammable, non-wieldable, or an aluminum plate to keep safe the areas you wish not to be burned.

10. Bracing

Having constructed the basic skeleton required, you can now add braces. At a minimum, you can start welding in a straight piece on the inner part of the main hoop, to offer a nice anchor point that will be used in shoulder belts.  Additionally, if you want convenience, make sure you raise the bar somewhere high past the driver’s shoulders.

Also, you wish the door bars to safeguard you from collisions that might come from the sides. As you did earlier, make sure you fish mouth the tubes to allow them to fit properly.

11. Don’t Paint the Cage

When dealing with a stunt car or a race car, make sure you don’t paint the cage to allow you to inspect the cracks. You can use a clear coat, that prevents rust but will still expose any chances of cracks.

Glossary:

MIG welding: it’s a welding process that makes use of a motor-driven spool of consumable metal wire as a filler material and combined electrode. This welding process is easier to learn as it’s not precise like other welding processes.

TIG Welding: It’s a welding method where a welder uses a tungsten electrode that’s non-consumable to combine and heat the filler rod and the work piece.

Base Plate: It’s a precisely-ground plate that works as the foundation of a fixture.

Tacking: An activity that involves fixing all the metal parts together using small welds that you can easily snap together to check on the measurements then allow for adjustments before getting to the final weld.

Tips On How to Build and Weld a Roll Cage

Check On Legality

Basically, before fitting a roll cage, make sure it goes handy with all the legalities needed. Ensure it complies with the CCDS and CAMS requirements.

Use The Required Materials

A good roll cage must begin with proper tubing. For added convenience, experts use either 1.75 inches or 4.5-centimeter circular tubing as it delivers all needed extent of strength as well as lightness.

Be Sure of the Best Weld Quality

When a cage roll is welded properly, it can be a very expensive tubing assembly. Most of them are fixed together using MIG welding or TIG. However, the TIG process of welding is the best as it delivers a stronger and cleaner joint with reduced splatter.

Use The Sills Always

The simplest thing to do while constructing the unit in your car is to place it on the vehicle’s surface floor pan alone. But the challenge here is, you can simply get torn when exposed to a rigid roll-over. The best thing here is tying the unit on the boxed sills of your car. You can do this with the foot boxes or the ‘L’ shaped pads and create great horizontal sections that you’ll use to fix the hoops into.

Ensure The Roll Cage as Tight as Possible

One challenge with most ready-made kits is that once done, they can’t be near the skin or body of your car. Doing this will offer reduced protection and offer less room for the driver. However, a good structure is that which sits closer to the edges of the car. By the way, a perfectly built car roll cage should be closer to the seals to make it harder to pass through a small paper inside the spaces.

Make Use of the Suspension Pick-Up Areas

A properly designed unit is constructed for protection purposes, and shouldn’t affect your vehicle’s performance level. Therefore, due to this, make sure the cage is tied in as many suspension areas as possible. Doing this will assist the car’s junction flatter and lowers the chassis inherent flexing which happens while moving at a high speed in a corner.

Make Sure the Tubes Meet the Hoop at One Point

To arrive at the proper use of force transmission when performing a roll-over or during a collision, the structure must be ‘backed up. Simply make sure that the bars are converging with all hoops in one place. This activity will transport the roll-over force properly. This will lower the risk of roll cage failure.

Maintain Highest Headroom

Make sure you always give yourself maximum headroom while constructing a roll cage. Doing this boosts your entire driving experience making it easier to access and more comfortable.

Build High Knee Bars

Even though most roll cage designers are designed to fit on the kneebars, the best thing here is making them a bit far from the knees.  Most kneebars are located behind the dashboard in properly designed roll cages. You can easily feed it via the hind side of the dashboard then bolt it back into the right place.

Give It an Amazing Paint

Sometimes paint may fail to provide more protection to your car. You don’t have to be worried as the paint will make it look slicker, professional, and safer. If you decide to powdercoat your roll cage this can also deliver an enhanced look. For more information on the best poweder coating guns for 2021 [Read our Full Guide]

Wrap up!

That’s how to build and weld a roll cage. As you can see, the procedure isn’t hard. A roll cage comes with many benefits that are objective and significant. For instance, it’s hard to refuse that a roll bar offers an aesthetic touch to your car. Additionally, you can use them to anchor points used for racing harnesses.

Adding a roll cage to your car is the best option. If you wish to use the back seat for your purposes, then you can’t build a roll cage on your car. But if this is the sort of a car that you are removing the seats to save on weight, then you need extra safety protection.

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