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 really complicated for removal, especially when you want to save as much of the original metal as possible. One of the ways or removal is to drill put spot welds.
Drill them out
For drilling out spot welds you can use spot weld drill which essentially has 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. The next method is by far the most simple and easiest way. No special tools are required all you will need is a drill and a set of drill bits.
You can get a drill bit from most auto shops that is made for drilling out spot welds – cobalt bits. They have a flat cutting surface with a ‘point’ in the center, line this up with the center of the tack and drill down until you have gone through the first layer of steel. You can also use a solid carbide drill bit or a brad point drill bit for metal. Another option is to grind the point on a HSS drill bit to make it look more like a spade bit and rill only through the top layer. You will need a grinding wheel with sharp edges.
This method with drilling 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 can have its disadvantages. First is that it is nearly 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.
When you are drilling, you drill through the center of the spot welds. If you have a problem with the drill walking on or moving around it may be wise to use a center punch and hammer to tap a small indention in the center of the spot weld location.
Please pay attention whenever you are doing any type of drilling whether it is with a specialized spot weld cutter or with a normal drill bit you should always use some kind of lubricant or cutting fluid which will help maintain the bit cool and increase the life span of your bits.