Aluminium, Steel Fabrication and Repair Specialists

Custom Gas Tank Fabrication

Here at KP Fabrication & Welding, we offer a range of custom aluminium products, including awnings, UTE canopies, ramps, ladders, toolboxes, and bull bars, among many others. However, maybe you’re more into the DIY side of fabrication and welding? We know how much some of our customers enjoy working on their own DIY weekend projects, and that’s why we’ve put together this useful guide to help you fabricate your own aluminium fuel tank. On the other hand, if things get too complicated for you, don’t hesitate to contact KP Fabrication & Welding for assistance!

First Step: Design your Aluminium Gas Tank

You can begin by taking measurements of the space where you plan to place your gas tank. Keep in mind that this process may be time-consuming, therefore we recommend getting a piece of paper and pencil to draw your potential design whilst taking the measurements. Remember to consider the space you’d need for any fuel pick-ups, filler, vents, level sensors, mounting straps and lines. Moreover, keep in mind that you should place the tank in an area where the exhaust won’t cook it. With that said, it’s important to build some heat shielding around the chosen area.

Second Step: Build your Model

Once you’ve finalised your fuel tank design, it’s now time to create your prototype. Be sure not to skip this step because you would not want to spend hours and a lot of money on a final product, only to find out that there’s something missing in the design or that it does not fit. This can be easily completed using cardboard materials. With that said, follow the steps below:

  1. Construct a cardboard model of the fuel tank, using all the measurements you wrote on your plans.
  2. Make sure that the cardboard model contains all the actual pieces that you will cut out of the sheet metal.
  3. Tape the cardboard pieces together following your fuel tank design.
  4. Check if it fits the area where you plan to place the fuel tank.

Third Step: Build a Baffle or Sump into your Fuel Tank

After cutting your aluminium materials according to the pieces in your prototype, you now have to decide on how you plan on dealing with the ‘tank slosh’. This term refers to the fuel moving around inside the gas tank whenever you go around a corner or accelerate. It’s worth noting that tank slosh can starve the fuel pump when the vehicle is running low on gas, which can cause problems by drying out the fuel pump and causing the motor to grenade. With that said, you should seriously consider the following options:

Fuel Cell Foam

You can stuff the tank with fuel-resistant foam that will slow the sloshing motion of the liquid inside the tank. This allows the fuel to have more time to move back and surround the pump pickup. A lot of drivers have used fuel cell foam and have tested it to solve the problem, however if you have a larger tank, this might not cover the extreme sloshing that takes place inside it. Since the dimensions are bigger, there are more movements inside the tank.

Fuel Sump

This is something you can build inside the tank to surround the fuel pump pickup. Basically, the walls keep the pickup submerged in fuel. Usually, there are small holes in the bottom of the walls, allowing small amounts of fuel in and out. All the while, there won’t be drastic changes to the fuel level, and the return fuel line will be discharged into the sump while feeding it with fuel.

If you want to avoid starving the pump pickup, building a fuel sump is one of the best options you can consider. You can easily build this by creating a circular base with a diameter of 4”-5”. Make sure that it is ¼ the height of your tank (so, if your tank has a height of 12”, then the sides of the sump should have a height of 3”).

Fuel Tank Dividers / Trap Doors

If you look at the fuel tank or cell of any race car, you will notice that they are divided into small sections with trap doors or small holes between them. Essentially, this method turns any large fuel tank into several small ones, which is important because smaller fuel tanks don’t have enough space to allow the fuel to slosh around. As such, the fuel pump pickup is kept submerged at all times. The fuel slowly moves between the cells because of the hinged doors or small holes that are drilled into the bottom of the walls. Moreover, even with rapid acceleration, there would not be much fuel movement inside the tank.

As we’ve mentioned, the primary reason why fuel tank dividers are essential is to keep the pump pickup submerged at all times, however, there are many other good reasons why this is done. Race cars have 100+ pounds of fuel shifting its weight around, potentially wreaking havoc on its balance. As such, the fuel’s weight is kept in small areas. If you’re building your fuel tank for this purpose, you should not ignore this important step. Creating trap doors require more careful planning and execution. On the other hand, it shouldn’t take much of your effort and brain cells to drill some holes on the bottom of the walls.

Fourth Step: Weld the Fuel Tank Together

It’s now time to actually put together your fuel tank- but keep in mind that whatever material you use, it will still move and warp on you. Typically, fuel tanks need long welds that require extended periods of heat, which may move and warp the metal. In order to successfully weld the materials into your desired shape, you need to clamp the tank in as many places as possible before you begin.

After that, you need to tack weld in many places to keep things square and in place, but you also have to make sure that you are moving to different welding areas of the tank. This means that you shouldn’t just work on a side of the tank and leave it- you have to set it up, tack weld it, then move on. Before you can proceed to final welding, you have to tack together the entire fuel tank. Make sure you weld a small section of one side of the tank before you move to another side. Occasionally take breaks to let the tank cool, and prevent it from warping.

Fifth Step: Lay Out the Final Pieces

The final step is to lay out the return, fuel pickup, vent, fuel gauge sender and fuel filler neck. These are the pieces that will allow the fuel to move in and out of the tank.

Sixth Step: Check if there are Leaks

Next, you have to pressure test the fuel tank to ensure that there are no leaks. Some would opt for water, but if you have small pinholes, it might work best to discover leaks. As such, we recommend drilling a small hole and applying pressure to the tank. By placing a little soap and water on the welds, you will be able to discover leaks. Make sure you follow this step to ensure success on your fuel tank project.

Seventh Step: Mount the Aluminium Gas Tank

Mount the tank securely to the vehicle and make sure that it is not rubbing or adversely contacting anything. If you’re planning to use the vehicle in a sanctioned event, you have to remember to research the organization’s rules on mounting fuel tanks or fuel cells. It’s worth noting that certain organizations have specific rules for those who are using non-OEM fuel tanks.

Get your Aluminium Fuel Tank Welded by Professionals

A lot of ready-made fuel tanks or cells in the market are made of aluminium, and the great thing about this material is that due to the oxidation layer around it, it becomes extremely resistant to corrosion. Aside from that, it is lighter in weight compared to other materials with the same strength.

However, it’s worth noting that aluminium is quite difficult to weld, and this is also the reason why not all metal workshops offer aluminium welding services, unlike KP Fabrication. When you’re not so confident in your own DIY skills, we suggest on bringing your fuel tank design to us so that we can do the rest for you. You can still keep it your own project by creating the pieces and design.

Just give KP Fabrication & Welding a call today and let us discuss a special arrangement for your project.