Top trunk - what is it? A functional element of a modern car or an unnecessary part that does more harm than good? You can argue about this endlessly, because each driver has his own needs and methods of operating the car. Some people use a vehicle only to get to work in the morning and home in the evening. And others cannot imagine their life without active sports: cycling, skiing and snowboarding. The last category of people, perhaps, most of all needs to install additional space for attaching large items. By the way, it is quite possible to make an expeditionary trunk in the garage with your own hands.
Do you need a roof rack?
Not all modern cars have an additional expeditionary trunk, however, this is a very important and useful part of the car. Usually they think about it when it is necessary to transport a large object. Owners of cars with a coupe or sedan body type will be forced to hire cargo carriers if they need to buy building materials for a summer house or garage, because boards and pipes simply will not fit in the trunk. Even an ordinary bicycle can not be stored in the standard luggage compartment of every car. Some might argue that there is a trailer for these purposes. But driving such a vehicle requires certain driving skills, and not everyone has a trailer. The way out of such situations is to purchase or independently manufacture a roof rack for your car.
Such luggage racks can be divided into two categories:
- boxes;
- arc-crossbars.
The former are more compact and have an attractive appearance. In addition, they protect your belongings from dust, rain, snow and even bright sun. However, they are able to accommodate much less things than arch-crossbars, and it is almost impossible to make them yourself.
But the second option is more functional, and it’s also easy to do it yourself.
Modern manufacturers are increasingly producing combined types of luggage racks. For example, in one design you can combine a box and a holder for bicycles and other sports equipment. If you wish, you can purchase such devices in specialized stores, but making them yourself is almost impossible.
Pros and cons of expedition racks
If you're still not sure whether you need a rack in a location like this, check out the pros and cons of this part. The positive aspects of the expedition rack are quite obvious:
- it allows you to transport more things;
- protects the roof and its paintwork from external damage from above;
- it becomes possible to transport large items;
- if securely fixed, the load will not fall;
- the transported items do not block the driver’s view;
- frees up space in the car;
- for some body designs it becomes possible to increase the volume of the interior due to the empty luggage compartment;
- you can install gas equipment in the vacated standard trunk;
- this detail is easy to make with your own hands
Unfortunately, such a trunk also has negative qualities:
- the weight of transported items is limited by the vehicle's carrying capacity;
- Fuel consumption increases by 2 liters per thousand kilometers when the trunk is empty;
- you will have to put in some physical effort when lifting the load to the height of the machine;
- if the trunk is overfilled or is poorly secured, you can lose some of your things;
- improperly secured structures rattle and interfere with the driver;
- the aerodynamics of the car is reduced, due to which the capabilities for acceleration and maneuvers are reduced;
- the car becomes less resistant to side winds;
- The height of the car increases, which means you should be more careful when driving through tunnels or under low arches.
The need to install an expeditionary trunk directly depends on the operating characteristics of the vehicle. If you travel often, like to ride bicycles with family and friends, or do gardening work, then such an element of the car will be indispensable for you. In all other cases, having such a trunk will also not be superfluous; besides, it can always be dismantled and left in the garage, and, if necessary, installed back.
How to make a trunk with your own hands
An expedition trunk can be made using two methods:
- weld a metal structure with sides and bottom;
- make cross members for the roof rails.
Rails are a kind of railing installed on the roof of a car. Simple shaped weights can be tied directly to them, but this may damage the paintwork. Unfortunately, roof rails are not available on some car models, so sometimes it may be necessary to make a complete structure.
If you plan to use the method of attaching the crossbars to the roof rails, then the whole process can be divided into several stages:
- selection and purchase of necessary materials and tools;
- measuring car roof parameters;
- drawing up a design drawing;
- production of crossbars;
- production of fasteners;
- assembly of the structure;
- installing the trunk in its place.
If roof rails are not included in the design of the car, welding of a more complex shape of the trunk may be necessary. However, with a responsible approach to the situation, from the start of measurements to the installation of the finished structure on the car, it may take no more than one day.
Selection of material and tools
The choice of material for the manufacture of expedition luggage should be taken with full responsibility. Heavy materials will significantly increase the weight of the vehicle, which will affect maneuverability and acceleration. In addition, such materials are quite difficult to work with. Give preference to light and soft metals and structures. The optimal solution would be to choose aluminum, since it is light in weight, but at the same time quite durable. It is a flexible and soft metal, so working with it will not cause any particular difficulties. In addition, aluminum is not afraid of corrosion.
Of course, the price of this metal is slightly higher than many others. If aluminum is too expensive for you, pay attention to the profile thin-walled tube. It can also serve as a good material for a future product. But sheet stainless steel should be used only as a last resort, since it is quite heavy.
In addition to the metal itself, you will need other materials and tools. These include:
- welding machine
- grinder for cutting metal;
- clamps for car mufflers;
- polyurethane foam;
- grinding equipment;
- fiberglass with a density of at least 300 g/sq.m;
- car paint (if desired).
As for the paint, you can choose it to match the color of the car’s body, or you can choose classic black or silver.
Design measurements and drawing
In order to make the crossbars, you just need to measure the distance between the rails. But to make a more complex design, you need to decide on the size and weight of the future trunk, and at the same time draw up a project. The amount of materials you will need depends on this. To prepare a drawing of the future product, you need to accurately measure the length and width of the roof.
After this, create a drawing that will take into account the following elements of the trunk:
- parameters of the structure frame;
- length and location of the jumpers reinforcing the product;
- trunk bottom;
- height of the sides of the structure.
When designing the structure, pay attention to the following point: rectangular racks have a negative impact on the aerodynamics of the car. Therefore, it is recommended to make the front side more streamlined.
Method one: making crossbars and fasteners
First of all, let's start making the crossbars. Decide on their length in accordance with the drawing, and then get to work.
- Using a grinder, cut two crossbars to the required length. Make sure they are the same size.
- Apply foam liberally to the metal inside and out.
- Wait for the foam to harden.
- Now, using a sander, grind off all the excess and give the crossbars the desired shape.
- Cover the resulting products with fiberglass in two or three layers.
- Paint the item in your chosen color.
Photo instructions for making crossbars
After this, you need to start making fasteners. Clamps for car mufflers are used for them. In this case, all unnecessary elements of the clamp are cut off to leave only a flat plate. With its help, the crossbars can be securely attached to the roof rails.
To assemble such a structure, symmetrical holes are drilled in the rails on both sides. The distance between the holes should be the same as on the prepared mounting plates. After this, the crossbars are easily installed in their places.
If the crossbars do not fit tightly enough to the fasteners, you can seal these places with rubber gaskets.
Video: making crossbars and attaching them to roof rails
Method two: making a more complex expedition rack
The second method is more suitable for making racks intended for SUVs. It has a slightly different procedure, thanks to which you can create a more complex structure with a bottom, stiffeners and sides.
This method is best used if you are transporting really bulky items or if your car does not have roof rails to which cross members can be attached.
- Carefully study the pre-prepared drawing. Decide on the length of all structural elements.
- Using a grinder, cut the metal to make the frame of the structure. You should end up with two longitudinal and two transverse metal pieces for the bottom and top of the structure.
- Weld the metal tubes together so that you get two rectangles corresponding to the roof parameters.
- The lower rectangle should be reinforced with stiffening ribs, placing them across the structure at the same distance from each other. If desired, you can add a construction mesh to the lower frame.
- Now you should connect the upper and lower rectangle, thus forming the sides of the trunk. To do this, you will need metal pipes with a smaller diameter.
- Prepare an even number of metal pieces from 7 to 15 cm long, depending on the expected depth of the trunk.
- Place them symmetrically on all sides of the rectangle, and then weld the top and bottom of the trunk.
Photo instructions for making an expedition trunk with a bottom and sides
Weld four crossbars in the shape of a rectangle (you will need 2 of these blanks) Connect the upper and lower rectangles Add stiffeners to the structure Apply anti-corrosion primer to the metal
Please note that to improve the aerodynamic properties, it is better to make the front and rear sides not from a straight section, but from an arcuate section.
If you worked with a material that is not resistant to rust, be sure to treat it with a special anti-corrosion compound. If you wish, you can also foam the resulting structure, strengthen it with fiberglass, and then paint it in the desired color.
Video: making an expeditionary trunk with a frame and sides
If you do not have roof rails, to install such a rack you will need to drill into the roof and secure it using special brackets. Unfortunately, this can cause rust to appear in the holes when moisture gets on the metal, so it is better to contact a specialist auto repair shop to resolve the issue.
Expedition rack accessories
Interestingly, some additional devices can be installed on the top trunk to make life easier for the driver. So, for example, if you often visit the dacha and carry special equipment with you, the structure can be equipped with a special mount for a shovel. The same mount can be used on fishing trips to secure fishing rods.
You can also easily install a mount for a radio antenna on the trunk, which will significantly improve signal reception. If you often ride outside the city, in places with a large concentration of trees, then you need such a thing as branch guards. One of the sides can be attached to the frame of an expeditionary trunk, thereby protecting the windshield from damage.
But the most popular additional equipment for this element of the car are lighting elements, the so-called chandeliers. They are a series of headlights that illuminate a larger area in front of the car than conventional low and high beams. Many people install fog lights on the trunk, but the principle of supplying and dispersing light in them is not very suitable for lighting from above. Today you can easily find special lamps for overhead light sources on sale.
As you can see, making a trunk yourself is far from the most difficult procedure. Of course, when making a complete structure with a bottom and sides, you need to have certain skills in welding metal structures, as well as special equipment. Therefore, in some cases it may be advisable to consider the option of purchasing and installing a ready-made part.
Quite often, a Chevrolet Niva car owner, when driving long distances, is faced with the problem of not having enough space in the luggage compartment. In this situation, the roof of the car, on which you can install a special box, is very helpful.
It comes in various types:
- Short. Occupies one third of the roof
- Average. Occupies one second of the roof
- Long. Takes up the entire roof
To determine the length, you need to understand what tasks it must perform during the trip. If there are not a lot of things, the first option will do. The second option is perfect for trips to the country, but the third is ideal for transporting skis and other equipment. The price for them is quite high and in order not to resort to large expenses, you can make a box on the roof of the car with your own hands, for this you need to finally decide on the length, since the material from which it will be assembled will directly depend on this.
In order to assemble the bases, it is necessary to prepare bolts, as this will help securely fasten all structural elements. To add rigidity, polycarbonate is installed in the base. A side is made on both sides, which can be secured with special locks or rivets, it depends on the chosen material. You can choose any material for covering, but, as a rule, banner fabric is used, since it has moisture and light-resistant properties, and you can also choose tarpaulin fabric. To make it more attractive, you can order any design. 
One important detail is the choice of a reliable lock. So that it functions well under the influence of low temperatures.
Build process
- Cut the fabric and sew it into one piece
- To give the material strength, it is better to sew all elements together with fishing line
- To make unloading things safer, it is better to do all the tightening on the sides
- To make the structure more rigid, it is advisable to place a plate in the case
You can install an additional option in the form of lighting in the front part of the trunk, and when you turn on the light at night, it will be illuminated, and on descents and ascents, the car in front will know in advance about your approach.
But before installing the additional one, it is necessary to install roof rails on the Chevrolet Niva; these are a pair of metal arches that are attached to the roof.
There are two types of roof rails:
- Longitudinal
- Transverse
- Combined
The first option, as a rule, comes already equipped with an SUV, but the second is installed on any type of body. Combined ones are already more complex, they include additional cross members with longitudinal rails. Their distinctive feature is reliability and increased load capacity. When choosing, you should pay attention to the operating instructions that come with the kit; it should indicate which models they can be installed on, since the slats can be fixed differently in different cars. It is also important what material they will be made of, and it is better to choose aluminum or steel structures. Metal structures have a much shorter service life and lower load capacity.
If you have any doubts about your choice, it is best to contact your car dealer and find out which model to choose for your car.
As you can see, assembling and installing the box yourself is not difficult; the main thing is to decide what type you need, choose high-quality material so that the structure lasts as long as possible. If you take this issue seriously, you can assemble a design that will not be inferior to the factory ones in terms of basic characteristics and build quality.
It is a pity that when purchasing a car, a roof rack is not provided. This is a very convenient design for transporting all kinds of things: from small and light to heavy and bulky, as well as strong-smelling. And it is not always possible to buy a ready-made homemade or factory-made trunk.
There is a good way out of this situation. Namely, create a roof rack with your own hands. This version involves savings in the family budget. Another name for a homemade trunk is expeditionary. It cannot transport heavy or bulky cargo. It is intended for personal belongings, tents, skis and snowboards, mattresses and large umbrellas, as well as small furniture.
You can also make the most popular autobox. It is convenient because it is protected from the environment even in bad weather and from theft. And if you make it streamlined, then there will be no excessive fuel consumption.
How to make a roof rack with your own hands
In general, roof racks are divided into two types:
- boxing;
- arc-crossbar.
Advantages of expedition luggage racks:
If you make a popular car box yourself, it will be convenient because it will protect you from rain in bad weather and from theft.
- more functional;
- holds a lot of different things of any configuration;
- holds large items;
- protects the roof from damage from above;
- does not obscure the driver’s view.
Disadvantages of an expedition rack:
- luggage weight limit;
- fuel consumption increases;
- difficulty in packing heavy loads;
- if secured incorrectly, there is a fear of losing part of the load;
- reduced aerodynamics;
- poor vehicle stability in cross winds.
Transportation of large cargo
For luggage items, a basket shape with sides is suitable. For transportation of long items there is a flat open platform.
To make a homemade one, you should carefully measure the linear dimensions of the roof. The trunk must not extend beyond the roof in the area of the front glass or interfere with the doors. Ideally, it is better to follow the dimensions of the factory racks designed for these models. Dimensions can be found on manufacturers' websites, or on the roofs of cars of acquaintances and friends.
Next you need to determine the type of trunk. For luggage items, a basket shape with sides is suitable. For transportation of long items there is a flat open platform.
Determining the number of mounts for a car roof rack with your own hands:
- four support points suitable for hatchbacks and sedans;
- if the roof length is over 2.5 meters, then it is better to make six fastenings.
Homemade trunk with sides
Now it is necessary to make drawings of the expeditionary trunk indicating the dimensions. You can also work from a sketch of a factory model.
Of all the materials for the manufacture of luggage structures, an aluminum alloy profile is best suited. It is easy to cut, bends, does not corrode and is lightweight. A structure made of steel will be heavy, which in turn will reduce the weight of the cargo being transported.
You will need a frame made of a profile pipe with a cross-section of 20x30 mm and a wall thickness of 2 mm. It is not advisable to use round pipes, since the load will slide off them during transportation.
You will also need tools and components:
Of all the materials for the manufacture of luggage structures, an aluminum alloy profile is best suited.
- welding machine;
- electrodes;
- ruler;
- construction tape;
- angle grinder;
- metal discs;
- drill;
- drill;
- nozzle for cleaning welds;
- set of mounting components;
- clamps for muffler fastenings;
- polyurethane foam;
- metal paint (preferably matching the color of the car).
Drawing of a homemade trunk
Once the drawing is ready and the tools and components have been purchased in full, you can begin manufacturing the cross member for the roof rack:
- Determine the transverse length. They must be the same in size.
- Cut the profiled pipe into several parts to create longitudinal and transverse guides.
- Weld the trunk parts, clean the weld seams.
- Seal them with polyurethane foam inside and out. Usually one bottle is enough.
- After the foam has completely dried and hardened, grind it down with a sanding machine. Initially, you need to make cross members in the shape of a parallelepiped. Then, if desired, they can be given a rounded appearance. The main thing is that they look like “family” in relation to the car.
- Then, for strength, cover the foam with fiberglass in 2-3 layers. It is advisable to take fabric with a strength of at least 300 g/m2.
- For attractiveness, the crossbars can be painted in any color (usually black, or the color of the car).
Manufacturing of fasteners
When making a trunk, you need to remember safety precautions - you cannot load the roof of the car over 70 kg.
First way. Take a clamp for attaching the muffler from any car. This is a flat bracket on one side and an arc that goes around the pipe on the other side. Saw off everything else from the flat plate. Now it will fit tightly to the crossbars and to the roof rack arches.
Second way. Use U-shaped brackets with threads. Instead of nuts, attach wings, with the help of which it will be very easy to unscrew and tighten.
Fastening the crossbars
To attach the crossbars to the rails, holes must be made in them. Measure them symmetrically on both sides, taking into account the holes in the mounting plates. Drill carefully.
Place the trunk tightly on the roof rails. If there is no tight fit somewhere, you can use rubber gaskets. Securely secure with bolts and nuts. It is also necessary to remember about safety precautions. The car roof cannot be loaded with more than 70 kg.
Fans of long trips are interested in learning how to make car roof boxes with your own hands. Modern cars, for all their advantages, have rather small trunks. Therefore, many drivers are forced to use various additional devices. Most often, autoboxes are used. They allow you to transport various loads on the roof. This way, you can transport things without fear of getting them dirty or wet. Also, unlike conventional frame racks, car boxes are more aerodynamic. Types and types How to make car roof boxes with your own hands? First you need to decide on the type of trunk. The materials used and the complexity of assembly depend on this. The final choice of type is influenced by the cargo that is planned to be transported. Car boxes differ mainly by the type of fastening. The most familiar to domestic motorists is the drainage ditch. It can be found on many cars, located along the edges of the roof. Usually, ordinary luggage racks are attached to them, this is done using clamps with bolts. Some models have roof rails. This allows you to install fairly large car boxes on the roof. There are special fastenings for completely smooth roofs. The boxes are divided into 3 groups according to their length:
- Short– occupy about a third of the roof;
- Average– they are a little more than half the length of the roof;
- Long- equal to or slightly longer than the roof.
Any material can be used. Most often they use something like a tarp. For greater aesthetics, you can take banner fabric. She is quite flexible. At the same time, it does not allow light and moisture to pass through. At the same time, you can order printing of drawings, which will make the car more attractive. It is important to choose the right lock. Please note that if it is exposed to snow and ice, it will freeze in winter. Therefore, when cutting fabric, provide a safety valve. You should also use zippers designed for skiers. Assembly. First you need to cut the fabric into fragments. After which they are sewn together. It is better not to use ordinary threads. Instead, it is better to use fishing braid or fishing line. This will give the seams greater reliability. It is better to do zippers from the side of the roadside. This way it will become less dirty. And unloading will occur more safely. Having sewn the cover together, a plate is placed in it, giving the structure rigidity. They attach it all to the crossbars. Autobox can be used. 
Additionally Take the time to add a little lighting to your expedition rack. To do this, install a pair of white LEDs in front. They are connected to the car lighting. When the low beam is turned on, they will also light up. This is done for greater traffic safety. On a night road, a car with such a design is visible much further. This is especially true for highways with a large number of descents and ascents. Oncoming drivers will switch to low beam in advance, which will protect you from being dazzled. Conclusion. If you travel far and with a lot of things, then sooner or later you will have to worry about an additional trunk. That’s when the question arises, how to make auto boxes on the roof of a car with your own hands. It's not that difficult to do. It is important to choose the right material for boxing. And don't go wrong with the sizes. It is also important to take into account the requirements for fastenings and locks. It’s a good idea to install additional dimensions. As a result, you will get a car box that is not inferior in characteristics to the factory one. Often the prices for branded roof boxes shock car owners so much that some decide to undertake grandiose experiments and try to make a box themselves. The most affordable material, more or less suitable for creating an imitation of a hard luggage box, is plywood. The fact that a homemade box is nothing more than an imitation is proven by any crash test. The test video clearly shows that the DIY roof box does not pass standard tests. A homemade plywood roof box literally shatters into pieces in emergency situations where the factory one has every chance of remaining intact.
Disadvantages of assembling a homemade plywood roof box
- In addition to the very labor-intensive manufacturing process from creating a drawing to assembling elements homemade boxes on the roof of a car also have the problem of calculating the final weight . To assemble such a “Lego box” you will have to put quite a lot of fasteners on the connections. A set of hardware itself can weigh up to 3 kg. This is an additional load on the car, which is absent in polymer factory boxes.
- The weight of painted plywood, stiffening ribs, adhesives and fasteners for stitching the elements of the trunk of the box, created with your own hands, eliminates any hints of aerodynamics . Even attempts to copy the shape and proportions of the original box will not help reduce and evenly distribute the weight of a homemade box. As a result, creating an aerodynamic car roof box with your own hands is as unrealistic as assembling a racing car in a garage.
- Plywood, to put it mildly, does not have the properties of ABS plastic even after processing primers, car paints, yacht varnish, lamination and other attempts to protect your homemade roof box from external influences.
- In addition to the difficulties of protecting from moisture, home-grown craftsmen want to make a roof box with their own hands that is at least a little similar to the factory samples. In the overwhelming majority, such a task is beyond reality and makeshift box trunk does not look like elegant boxes , developed by professional engineers.
- You will have to make your own system for opening the roof box . At this point, the creative ideas of the “Kulibins” extend to the use of furniture fittings, removal of mechanisms from household appliances and other exotic techniques for equipping boxes. Of course, you cannot count on trouble-free operation of mechanisms that, in principle, are not designed for boxes.
A short review of the main problems of plywood boxing clearly proves that doing craft work is unprofitable. However, there is an alternative to expensive boxes. The Avtodrechta company has developed its own luggage box model in full compliance with advanced technologies. You can purchase a high-quality box at a price that is almost equal to the cost of a homemade one, only without the risk of losing the comfort and safety of using a car with a luggage box.
