Drilling spot welds to remove unibody panels such as your cowl, rear quarter panel, floor pans and wheel wells can be tedious, but it is a fairly straightforward process. This guide will help you tackle spot weld drilling like a pro. Please remember to indicate below if this guide is helpful to you!
Tools Needed
- Sand Paper and/or Wire Brush
- Drill
- Pilot Drill Bit: 1/8″ diameter
- Spot Weld Cutter: 3/8″ diameter
- Heavy Oil
- Hammer
- Flat Metal Chisel
Spot Weld Drilling Process
- Locate the spot welds needing removal
This is done by looking for small, round depressions located every few inches where the body panel is attached to the vehicle. If your vehicle is severely rusted or has been painted several times, these welds can be difficult to locate. You would then need to clean the spot weld areas with sand paper or a wire brush to locate the welds. Please see our Locating Spot Welds for a Unibody Panel Replacement guide for more information.
The drill bit is pointing at the small depression/spot weld.
- Using your 1/8″ drill bit, drill a pilot hole through the center of each weld
A pilot hole is a centering hole for the spot weld cutter. Helpful tip: Dip the tip of your drill bit in heavy oil prior to drilling each spot weld. This will prolong the life of your drill bit.
This picture shows the pilot hole being drilled.
- Once all pilot holes are drilled, use your spot weld cutter to drill a hole through each spot weld.
Using a specialized weld cutter minimizes the damage to the panel underneath the panel being removed. When drilling with the weld cutter, only drill deep enough to remove the desired panel. When I drill a weld, I watch the drilling area change from clean metal to light surface rust. This would indicate that I have just reached an area between the sheet metal panels. At this time, there is usually a little “poof” of rust dust. I stop at this point, since I know I have just drilled through the first panel without over-cutting the second panel.
Here is one style of weld cutter. This is a sheet metal bit, 3/8″ size.
Here is the weld cutter at work, drilling the top layer of the spot weld.
The weld is drilled!
- After all welds have been drilled, carefully use your hammer and flat chisel to separate the panels.
This is done by laying the flat edge of the chisel between the panels and gently hammering to loosen any bits of weld that were not cut by the drill. - Now that your panel is removed, you are ready for the next process. Please see our Patch Panel Installation – Unibody Panel Replacement Guide for further information.
You are on your way to spot weld drilling! I have drilled over 5,000 spot welds throughout the last 15 years and I will probably drill 5,000 more in this year alone!
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