Online School With JBugs

Lesson 6: Repairing Damaged Fender Nuts

In our second lesson, we discussed the process of tearing down and inspecting the body of a Beetle to assess its current state. We listed the steps to removing the fenders and mentioned that it is very common to find that the fender nut inserts on the body are damaged or missing altogether.

This lesson we will cover the process of replacing those inserts. It is a fairly simple process, but it does require a few power tools to be done correctly. We will begin the procedure assuming you’ve followed the steps listed in Lesson 2 and have already removed the fender. If you haven’t, you can get up to speed here.

Tools

Like mentioned above, we will be assuming you already have the fender off, so the tools list below are specific to the task of replacing the nut inserts.

To replace the nut inserts on the body you will need the following tools:

1. Hammer (if you need to knock out an old insert that is rusted/stripped)
2. Punch (same as with the hammer)
3. Electric drill with stepped bit
4. Welder
5. Angle grinder with wire wheel and flap sanding disc
6. Fire extinguisher

Parts

All you really need for this procedure are our Weld-In Flange Nuts (replacement nut inserts). You will need one per damaged insert on the body. However, it is helpful to have something threaded into the nut insert to prevent the threads from deforming due to heat. 8x1.25mm studs are readily available from most hardware or auto parts stores (or your own random hardware bin), but if you don’t have one, you can find it here.

Likewise, you don’t have to do it, but we strongly recommend spraying the new metal down with primer to inhibit rust once it has cooled down. It’s not essential to properly installing the new nut, but a little bit of after treatment will save you from having you repeat your efforts in a few years.

With all that said, now is a great opportunity to replace your fender hardware as well since you already have the fender off of the car. If you find that your existing mounting hardware is damaged, our Fender Hardware Mounting Kit comes with the bolts, washers, and nut you need to install one fender.

Procedure

To replace the nut insert do the following:

1. Set up your work station in a well-ventilated area and make sure you’re not welding near any fuel lines! Some of the fender nuts are in close proximity to the vent lines on some Beetle models. This is why you want a fire extinguisher on hand.

2. Knock out the old insert using the hammer and punch, if needed.

3. Use the stepped drill bit to open up the hole on the body. This step is important because how large the hole needs to be depends on where you want the flange to be relative to the sheet metal. If you want the flange flush with the sheet metal, you will need to drill the hole just large enough to allow the flanged portion to pass through. If you want the flange on the inside (on the trunk side) or outside (on the wheel well side) of the existing sheet metal, you need to drill the hole slightly smaller than the flange. Sam welded the flange nut on the trunk side of the sheet metal in the pictures at right.

4. Remove any paint and debris from the surface you plan to weld using the wire wheel.

5. Thread the stud/bolt into the front (cylindrical portion) side of the new weld-in flange nut.

6. Position the weld-in nut where you want it once complete. Make sure that the stud and cylindrical portion of the weld-in nut are pointed into the trunk area.

7. Use whatever means you like to hold the nut in place as you tack flange to the body. You can see from the image shown that Sam just held the stud from the backside with his other hand (hard to see, but he is wearing a glove) while tacking it in place.

8. Weld up the rest of the nut.

9. Use a flap wheel and wire wheel to clean up the surface one complete.

10. Once everything has cooled down, wipe down the area with some kind of cleaner/solvent to remove any fine particles and spray down the newly exposed metal with primer to prevent rust.