While you’re tearing down your project it’s inevitable that you will come across some spot welds that need to be removed. They can be a pain to remove. especially when you want to save as much of the original metal as possible. Just like many parts of automotive restoration there is more than one way to do the same task. It all comes down to which method works best for you. All of these methods accomplish the same goal it all depends on what tools you have and how in depth you want to go.
Lets start with the simplest, Spot Weld Cutters, but even these have multiple variations.
The first and very common is this Spot Weld Cutter. It utilizes a small centering pin which makes contact with the panel first which stops the cutter from wandering. The pin is on a spring so once you put pressure into the panel it will depress and begin to cut through the panel. The cutting wheel is similar to a hole saw for wood which is slightly larger than the spot weld. These can be swapped out with different size cutting heads depending on your project. This type of cutter has an advantage over the rest because once the cutting head bores through the first panel the panels are able to be separated. You will not be left with a hole cut all the way through both panels. Spot Weld Cutters like these range from about $25-$80. This costs more than some other methods, but it is the most professional, accurate method for drilling spot welds.
The next spot weld cutter is slightly cheaper and performs the same basic function. This Spot Weld Drill essentially a very wide but flat drill bit with a self centering tip so it will not wander. These have an advantage of being made out of one piece of metal so there are no pieces that could break. They do have their drawbacks because each cutter is for a specific size spot weld, unlike the first where the cutting head can be changed out to accommodate various spot weld sizes. At a price point of $30+ dollars they may be more expensive than a standard drill bit, but they are far more accurate and last much longer than a standard drill bit (and won’t drill through both panels as easily).
The next method is by far the most simple and easiest way. No speciality tools are required all you will need is a drill and a set of drill bits. This method works very well but it takes a lot more time and it can wear down your drill bits quickly. Although it’s the easiest, using a drill does have its disadvantages. First is that it is near impossible to save both panels since you will have to drill completely through both panels. The problem with this method is that you will not be able to remove a lot of spot welds because even the best drill bits will get dull over time. One way to reduce the wear on your drill bits is to drill a small pilot hole first and then use a larger bit to remove the spot weld. This method is very time consuming and can be frustrating if your drill bits become dull.
If you don’t have a drill or drill bits and you still want to remove spot welds there is another method which is more of a last resort. The tools you’ll need for this are a Cut Off Wheel and a Hammer and punch or Air Hammer with chisel attachment. First cut a star shaped pattern directly over top of the weld, you will only need to cut through the top panel. Then using the punch hit the center of the cut lightly to break the rest of the metal free. If you are able to get to the under side of the panel this step may become easier withe use of a screw driver to pry the two pieces apart. This method should only be used as a last resort when you don’t care about the top panel.
The last method is also somewhat of a last resort but in a pinch it will complete the same task. Using an Angle Grinder remove the metal directly above the spot weld without burning thorough the panel. Once you have removed the majority of the first layer of metal, use a punch or chisel and hammer to break the rest of the metal free. If you are unsure of how much metal you have removed, hit the center of the spot weld and the outline of the spot weld will appear.
All of these methods will remove spot welds but only the Spot Weld Cutter and Spot Weld Drill will allow you to remove the weld without damaging the other panel. In the long run the higher price will be worth the time they save.