Although many people believe they know what pinch welding is, others may not be able to explain it clearly. Many think it is the sealant that you apply to a zip-lock slide. But is it true?
Because they resemble fish bones, pinchwelds can sometimes be called herringbone welding. Pinch welding uses a strong adhesive to attach metal plates. Engineers use pinch welding to make aircraft and other vehicles stronger and more waterproof. This blog will give you all the information about what pinchweld is and its applications.
Simple Understanding – What is a Pinch Weld
So what is pinchweld? It refers to two metal plates sandwiched together by two electrodes. A spot weld is created by applying high pressure to the metal sheets to weld them together. Imagine holding two sheets of paper between your thumb and forefinger. It is how pinch welding works.
The pinchweld is one of the strongest welds. Why can you say that? Because it forms a mechanical bond between metal sheets or panels. It is commonly found on safety equipment, bus bodies, and other transport structures.
3 Types of Pinchweld
There are three types of pinch welding. Each one of these welds is suitable for a specific application.
Flat Shaped Pinchwelds
Flat pinch welds are one of the easiest welds to create. These welds connect long, horizontal pieces of metal to cover the car’s machinery.
L Shaped Pinchwelds
L-shaped pinch welding is the most commonly used type in automotive manufacturing. Typically, you’ll see it under your vehicle. To build an L-shaped pinchweld, the welder needs two metal plates. They need to be connected. To make the overall weld L-shaped, one of the metal plates needs to be perfectly vertical, and the other needs to be horizontal. The two metals are then joined using a spot welding process.
After welding, you need to apply adhesive to the spot welds. You’ll end up with an L-shaped joint. This metal part will be visible on your car through the small metal flap that runs along the length of your car’s underside.
Z Shaped Pinchwelds
Z-shaped pinch welding is the most challenging type of welding. In effect, this type of pinch weld joins two L-shaped ones together. It is a difficult task. Because this requires high technical personnel ability. Two L-shaped pinchwelds need to be connected into a single connection. The operator assembles the two pieces of metal through the diagonal.
We see this type of pinch weld on the top front of a vehicle, usually on the windshield and windows. The welders will apply a urethane resin layer to the diagonal surface. This way increases the structural strength necessary for windshield or glass support. The Z shaped pinch welding on the top of the vehicle is less susceptible to wear than the weld on the bottom of the car.
What are Pinchweld Applications
Automotive Assembly
This technique is used frequently in automotive assembly. A pinch weld welcomes the car’s outer frame to its inner body. A pinchweld is an integral part of making a car door. It locks by pressing in from either side to maintain the car’s shape and structure.
Placing Jack
To help you find the crucial part of your pinch welding, companies make them place a small mark on the weld. This mark can guide you on where to position your jack. You can set the jack on either side of the pinch welding in cases with a mark. It depends on the vehicle’s material.
Pros and Cons of Pinch Weld
Pinch welding is an excellent solution to common problems like loose nuts and bolts. But it’s not perfect, and it has drawbacks.
Advantages
- This welding method is cheaper, more straightforward, and more effective than nuts or bolts for clamping different parts of the vehicle’s frame.
- You can use pinch welding to temporarily or permanently fasten two or more pieces of metal together.
- It provides an excellent place to put the jack.
- You can repair the pinch welds for mild damage, such as dents, rust, and breakage. But severe damage is irreparable.
- Pinch welding holds sheet metal together. These are particularly useful for heavy items.
Disadvantages
- It can be challenging to do if you need to pinch welds at tricky angles.
- The perfect type of metal is steel. Not all metal types are suitable.
- Pinch weld defects could lead to many problems, including cracked frames and fuel tank leakage. Even if the pinch weld isn’t showing any signs of being defective, it could still cause issues affecting vehicle performance.
Common Problems of Pinch Weld
Corrosion and Rust
If you ignore rusty parts, they can have an impact on the entire vehicle. You can start by removing any rusted metal with the help of a small tool or knife. After cleaning, you should install new sheet metal to reinforce the damaged section. Before you do the pinching weld, carefully align both steel plate pieces. You may need to do another pinching weld if necessary. After everything is welded together and reinforced, you can prime the area and paint.
Dent
Pinch welding often creates dents. First, you need to determine if there is any breakage. If nothing is damaged, align the pinch welds at the correct angle. You will find scratches after cleaning. Continue to clean up scrap and exposed metal debris. Finally, apply a coat of paint with a brush.
Breakage
If two parts separate, there will be a gap between them. In this case, you need to repair the pinch weld immediately. Find the gap and use a vise to glue the gap together. Re-solder at the end to maintain the fit. Once everything is done, the final step is priming and painting. So it looks good again.
How to Avoid Pinch Weld Damage
If you thought that a slight bend at the pinch weld would not cause damage to your vehicle, you’d be wrong. Clip welding is often damaged due to improper use. Most cars have an L-shaped pinch welding underneath to keep them structurally strong. It can become brittle and cause water to collect in your vehicle. It could lead to more severe problems.
Do Not Jack From the Pinchweld Directly
Avoiding jacking from pinch welding is the best way to prevent damage. You need to know where the jack points are to lift your vehicle. It is the best option. Check your manual to determine if the jack can be placed under the front cross member for a jacking point.
Use a Jack Pad
It is a simple step to distribute vehicle weight evenly. You can use wood blocks or thick rubber to make the jack pad. They can be placed between the jack and the pinch weld. It will ensure that the weight is distributed evenly rather than hitting one area of the car.
Use the Right U-channel Jackstand
To rest in the jack stand, place the U-channel jack stand perpendicularly to the pinchweld. This jack stand may slightly indent your pinch welds if the car isn’t balanced. Make sure the U-channels of your vehicle are just a little deep.
Pinchweld Rubber Seal
The automotive industry uses a lot of pinchweld rubber seals. They can provide excellent water resistance, sound isolation and dust protection, shock absorption, keeping you warm, and energy savings.
Final Thought
It is all about pinch welding. In a word, this is challenging to understand for non-professionals. Remember to reapply the seam sealer and undercoat after removing the pinch weld clamps. It will restore corrosion protection and appearance. It is essential to repair or refinish any damaged or removed paint.