If you want your car to become more fuel-efficient and quieter, it would be a good idea to perform some custom automotive work on it. Perhaps, you might want to enhance the exhaust or add another pipe. You can also give your vehicle a sportier look by adding custom bumpers. On the other hand, if you want your truck to have that extra muscle for off-roading, it would be best to install a body armour. All of these processes will require sheet metal fabrication which can include welding, joining, and punching.
When it comes to ensuring a successful custom automotive sheet metal project, the key is to properly choose and prepare the materials you need. As such, we’ve put together some useful information that will guide you through the process. Here are some essential tips in choosing the material for your project:
Aluminium or Steel: Which is More Suitable for You?
The great thing about aluminium is that it is lightweight and its metal sheets are more affordable than steel. However, it also requires specialised skills and equipment for fabrication. Since aluminium is thinner and lighter than steel, standard welding equipment would only cut through and singe it.
When you try to join the material with heavier rivets, you can easily damage it since it is lighter in weight. On the other hand, steel can hold up to the heat of the vehicle’s exhaust. Moreover, it does a better job at carrying the weight of a car, especially when you are customising shocks. That said, the choice is up to you. You have to consider your priorities and sheet metal fabrication skill level when choosing the material for your project.
You can easily find pre-fabricated tube structures that can fit over a car’s exhaust. However, it would still help if you know how they were made and what materials were used. After all, these factors will affect the tube structure’s durability and strength. Typically, hot rolled electric weld is used, but a better option would be mandrel bending.
Much of the tube’s strength can be retained when it is run over a mandrel. On the other hand, the piece may be weakened when a hot electric weld is used on it. When it comes to selecting tube structures for your custom pieces, it is best to opt for DOM or drawn over mandrel bending.
Keep in mind that the strength of your custom auto work is determined by how good your fasteners are. The lower the fastener grade is, the lower the strength will be. It can be tempting to get the lowest grade bolt or rivet. However, you have to consider that they will be subjected to so much wear and tear under your car or while holding your bumper’s weight. It would be best to choose grades five and up since they possess the tensile strength necessary for automotive applications.
Simply look at the head of the rivet or bolt and you will see the grade number. It is worth noting that grade eight bolts tend to be denser and when subjected to too much stress, they can snap. So, if you’re fastening metal on a custom automotive project, the aforementioned may be too high of a grade.
Properly Preparing the Sheet Metal
Whether you’re using a sheet metal that is new or old, it is essential that you clean it first. You can opt to start working with dirty steel. However, there are some welders who find it more efficient to work on steel panels that still have rust and/or old paint on them. You can surface damage and deformations by filing and sanding these things off. Essentially, the defects sort of become a guide coat as your work progresses.
You should start thinking about cleaning the panel materials by the time to get to hammer forming or welding them. Keep in mind that even if steel panel materials look clean, before they are shipped, they are typically coated with preservative oil. Before welding or painting the new metal, it is important that you remove the oil, using an appropriate solvent.
Cleaning the Sheet Metal and Removing Paint
There are various ways to clean the sheet metal. Before, the common practice was using muriatic acid (hydrochloric acid/HCL) to treat it. Welders also used to burn off the old paint by using a blow torch. On the other hand, these days, the aforementioned methods are not recommended or even acceptable.
You can remove the paint by using any solvents that are specifically designed for that purpose. Depending on what you choose, you will get an appropriate level of speed and thoroughness. General-purpose paint strippers would suffice if you are stripping paint from a large panel, like a hood or door. A great option would be an aircraft-type remover.
For removing paint and rust from larger panels like whole bodies, decklids, hoods, or doors, it would be ideal to try dip stripping. For this option, you would have to find a vendor that provides quality and effective service. There are systems that utilise heated chemicals and a lot of them provide enhanced cleaning through electrolytic action.
Make sure that you find an operator that is very careful when it comes to the chemistry that goes into their tanks.
Find a trusted dip stripper near you and take advantage of this method when cleaning your metal panels. It is worth noting that you shouldn’t drive a great distance just to dip strip a decklid or a door. On the other hand, it would be justifiable to travel far when you’re stripping a whole car.