Quite a huge amount of people believe they are aware of what pinch weld is. But in particular cases, they probably do not have a very precise notion. Most think it’s the adhesive that you need to put on a zip slide.
So, that is it? Pinch welding is a solid adhesive process during which metal pieces are attached closely together.
Pinch welds are frequently used by mechanical and aircraft engineers to make aircraft and cars more structurally sound and watertight.
In this article, you will learn about pinch welds, where they can be used, and ways with help of which some of the problems can be quite easily avoided.
Contents
What is a pinch weld?
During the creation of a pinch weld, two separate pieces of metal are joined by putting one on top of the other.
To melt the metals and create welded joints the welder should run a high-voltage current through them.
This process is often called spot welding. It received such a name because the metals are not joined or welded throughout their whole surface area but only in selected spots.
The spot welding process involves applying adhesives to the areas between the spots, after which the setup is reheated.
In a car assembly, a pinch weld is usually considered a spot at the front of the car where various metal components are welded together.
During this work, the outer frame of the vehicle is should be attached to the vehicle’s inner body.
So, such kind of welding is fairly often used in the automotive industry, mostly for sheet metal components such as car body panels.
So that’s how to pinch welding works. Also, it is mostly cheaper than many other kinds of welding.
Pinch welds are a relatively strong type of weld. This is because during a pinch welding is making a mechanical bond between metal panels or sheets.
Various kinds of pinch welds
There are a few types of pinch welding:
Flat-shaped
The flat-shaped pinch welds are probably the most simple weld to create.
These types of welds are mostly used for a purpose of joining long horizontal sheets of metal used as shielding coverings to the machinery of the car and equipment.
L shaped
The most popular pinch weld is quite possibly the l-shaped pinch weld. You can notice it in most cars.
It is the one that is found located under the length of the vehicle. To make this particular kind of weld, you should prepare two metal sheets.
The first sheet should be folded in the shape of the letter L, which means that it is bent at 90 degrees.
The second sheet’s portion should be flat or horizontal.
Two sheets should be positioned side by side and after that, they must be joined.
The work can be finished by applying adhesive. Eventually, you will receive an L-shaped joint.
Z shaped
The z-shaped pinch weld is two l-shaped pinch welds that were attached together.t one is a diagonal metal sheet with an L-shaped joint at the top and the second one with the same joint at the bottom.
The top front of the car has this particular type of joint. Z-shaped pinch welds are making the structure for the windscreen and the windows.
It is good if a urethane bead will be added on the diagonal surface. This is will make better the structure very much needed for the glass support.
Pinches that are positioned at the top are not as prone to damage as the ones that are placed at the bottom.
Talk about the pinch welds that you can see at the bottom of the car, there is the risk that you may by accident break the weld joints. The chance that it can happen is incredibly high if you do not use a jack that is created to lift your car from the factory jacking points.
Advantages and disadvantages of the pinch weld
Pinch welding can be an excellent solution to typical troubles like nuts and bolts that became loose.
But it’s not ideal, and it has flaws.
Advantages
- This particular welding method is less expensive, more simple, and more efficient than nuts or bolts that are used for connecting various parts of the vehicle’s frame.
- If you wish two or more pieces of metal to be attached, then pinch welding is not a bad choice.
- It can provide a fitting area for the jack to be put.
- The pinch welds can be repaired in case they were not severely damaged. But if it is quite serious, in particular cases the repair can be impossible.
- Pinch welding fastens metal sheets together. They are can be incredibly useful if items are quite heavy.
Disadvantages
- In case you wish to pinch welds at complicated angles it can be quite difficult to do.
- The ideal type of metal is steel. Not all kinds of metal are fitting for the purpose.
- Pinch weld defects could induce quite many issues, such as cracked frames and fuel tank leakage.
- Even if the pinch weld does not look defective, it could still induce some issues impacting the performance of the vehicle.
Typical issues of the pinch weld
There are can be some troubles. These are the most typical of them:
Corrosion and rust
- In case you are not taking care of rusty parts, they can have a quite serious effect on the entire car. Even new parts could be impacted by corrosion if not taken care of in time.
- In the beginning, rusted metal should be removed. A small tool or knife will fit this purpose.
- After that, you should install metal plates to reinforce the rusted section.
- It is better if you use suitable metal plates for your vehicle, with the proper thickness.
- Before the pinching weld will be performed, the two pieces of steel plate should be accurately aligned together. It must be done, to receive welding that will be suitable enough.
- Also, sometimes it may be essential to do pinching weld one more time.
- Right after you reinforced and welded everything together, you can begin to prime. Finally, you need to paint.
Dent
- Pinch welding quite often develops dents. If it is not damaged, then the pinch weld should be realigned to its standard angle. It will be easier to do with help of hammers and a locking plier.
- After you cleaned everything, you must be able to notice all the scratches and blemishes. You should keep cleaning up any scraps and pieces of bare metal sticking out. You can do this by using a scrapper. The final step is you need to take a brush and apply a coat of paint.
Gaps
- If two parts will be separated, it will create a gap between them. In case this happened, the pinch weld must be repaired as fast as possible.
- For a start, you need to find the gap. Then you should take a vise and use it for the purpose to glue the gap together. After everything was finished, all you have to do is prime and then paint.
How to evade bending pinch welds?
It would be excellent to know the fitting spot to place the jack.
So, where your car should be jacked?
If you indiscriminately place the jack just everywhere in the pinch weld may bend it. If it will be bent back in shape, there is a risk that it can make the pinch weld weaker.
There are quite many methods thanks to which you can evade bending the pinch weld placed under your car.
Let’s take a closer look at some of them:
Use a jack pad
- Instead of directly putting the jack on the pinch weld, you can use a jack pad. Jack pads are specially made for the purpose to be able to withstand the big weight and pressure of hydraulic jacks.
- If you did not purchase the exact jack pad that was created specifically for your car, then you can use a wooden block or a thick piece of rubber. You can take them and then put them between the jack and the pinch weld.
- This will help you to make sure that the weight is distributed evenly rather than hitting one spot of the car.
Use a universal pinch weld jack pad
- It can be a quite complicated job to find the right jack pad that will fit your car ideally. If you have this issue, you can choose as option universal pinch weld jack pads.
- Heavy-duty construction rubber was used for making this pinch-weld jack adapter. It can bear a load that weighs three tons.
- Two jack adapters are included in one package. It will fit perfectly for most vehicles. Thanks to it rails will be prevented from bending when using the jack to lift a car.
Switch the jack stand points
- There are possibly a few specific jack points on your car that you are comfortable with. But, if you will switch jack stand locations, it can be a quite smart move.
- Anytime you wish to jack your vehicle it is advisable to switch the spots. Doing so helps you to make sure that the structure of your car won’t be weakened over time.
- If you will be using the same area every time it will quite certainly make it weaker. There will be a huge risk of an accident.
Use the right type of jack
- Most modern cars have specially made jacking spots. But even in this case, it is fairly easy to receive a structure that will be deformed in case the wrong type of jack was used.
- It would be better to use a jack that features a special jack pad. The pad will distribute vehicle weight evenly across the weld.
- If you have the fitting kind of jack, it can help you to evade the creation of sensitive pressure points that can make the welds weaker.
Listen to the instructions of the carmaker
- This is another quite simple tip. If you will follow the advice of a carmaker it can help to make your pinch welds’ life longer. They usually know quite well the weak spots and strengths of your car.
To learn more about what is a pinch weld, check out this post here.
Frequently asked questions
What is the purpose of a pinch weld?
A pinch-weld also known as a spot weld is a method for attaching two pieces of sheet metal in a lap joint.
It’s frequently used in auto body fabrication and repair, where two pieces of sheet metal—most often those that form the car’s body panels.
Can you put a jack stand on a pinch weld?
Pinch welds can be used as a support point for jack stands, every time you raise and lower your vehicle.
You can jack from the front and rear center support points and lower the pinch welds directly onto the jack stands.
What is pinch in MIG welding?
In GMAW the electromagnetic forces, which are mathematically proportional to the square of the applied current, affect the mode of metal transfer.
The most well-known term that is usually applied to electromagnetic force is the pinch effect.
Pinch welding can give a narrow, but strong flame that is focused on the needed part, it is achieved by an induction coil, which results in electromagnetic forces.
Conclusion
Now you learned what the pinch weld is the area underneath your vehicle close to the front. It is where the various metal parts of the car were welded together.
This type of weld has quite many advantages. It is fairly cheap and simple.
Also, some tips would be quite good to know if you wish to maintain the pinch weld of your car.
If you need to read about whether can you weld rebar, please read our article.
