Fender Repair
November 19, 2013
REPLACING FENDER WIRES
by Ron Heppner
The process that I ultimately came up with is the result of attempting to repair the two front fenders by mig welding the cracks in the usual places. After welding and cleaning things up I found that the fenders were still too flexible and that they were bending too much where the cracks were repaired.
I decided to remove the spring wire and replace with new 1/8” spring wire. Before I even started I had to source the wire. My first choice was to try the Metal Supermarket. They didn’t have anything but they made a call for me to Dendoff Springs.
The contact there is:
Dendoff Springs Ltd.
Larisa Papirovskaya, Sales Engineer
12045 Old Yale Road
Surrey BC V3V 3X4
Tel: 604 580-3400 ext. 116
They would prefer that you call ahead and that will allow them to make up the order.
Once I had the material I then made tools for the different operations.
There are 3 steps to completing the job.
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Opening the bead and removing the existing wire.
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Welding and grinding any cracks or holes that need repair and reprofiling the bead.
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Bending and installing the new wire.
Step 1 – OPEN THE BEAD AND REMOVING THE EXISTING WIRE
I had to make a tool that would get under the lip of the bead and I made it from a hydraulic brake adjusting tool. The flat end was heated with a torch so that the end could be bent into a hook shape. (See Figure 1a) Note that the edge is chisel shaped so that you can get under the lip. ( Do not quench the hot end in water, the steel is harded tool steel and it will go brittle and break when used. Let it air cool.)

Figure 1a
Starting at one end of the fender, prise up the edge of the lip of the bead. Do not try to open it the full required amount. Only open the bead up enough to remove the wire, that would be half way. Open the bead one quarter of the required opening, then go back and open the bead up to the full amount required. If you open the bead up too much at one time you will stretch the metal.
Once the bead is opened the required amount pull out the wire. You should be able to slide the wire behind the fender edge bracket. If it is tight, open up the bead slightly and if you have to, cut the old wire. The new wire should slide in easily as it will not be rusty. The one thing that confirmed that I was doing the right thing by replacing the wire was that as I removed the wire from the first front fender it broke right at the place that I had welded a crack in the edge. The temper of the wire had been altered and it became very brittle and snapped.
See Figures 1b & 1c as to how to open the bead being careful not to apply too much pressure as to deform the face of the bead on the exposed side of the fender.

Figure 1b

Figure 1c
Step 2 – WELDING AND GRINDING ANY CRACKS OR HOLES THAT NEED REPAIR AND REPROFILING THE BEAD
Once the wire is removed you now can make any repairs that are necessary. Any cracks should be welded and ground smooth otherwise they will open up even more and you will be back where you started. If your vehicle has been in any fenderbenders the bead edge probably is a bit concave, it should be basically flat.
To acheive that I made a tool from 3/16” x 1 ¼” flat bar. With a shoe from the same bar welded at an angle (approx 45°). The shoe is just wide enough to fit flat in the groove of the bead. Note that the handle is undercut at the shoe weld, this is to allow the lip of the bead to slide in so that you can fit the tool tightly in the bead. ( See Figure 2a ) This is important otherwise you will do more damage to the face of the bead when you try to flatten the surface with a body hammer. (Just an aside, I polish the faces of my body hammers, first by sanding to get a ever so slight convex shape and then polish on a buffing wheel to get a mirror finish. This way you do not transfer any dimples to the work. This is especially important when working with stainless steel.)

Figure 2a
Note in Figure 2b that the shoe fits tightly in the bead and literally snaps into place.
By lifting up, pushes the bead out and at the same time tap lightly on the face to flatten the bead. Remember tap lightly or you might do more damage than good, you don’t want to damage the step in the bead. If there is damage this is the time to fix it.

Figure 2b

Figure 2c
STEP 3 - BENDING AND INSTALLING THE NEW WIRE.
When you take out the existing wire you might find, as I did, that the wire has similar toothed markings as does the edge of the fender. I suspect that to make this rolled edge there were two wheels, one on the outside edge of the bead and one on the wire pushing the wire home into the groove with a follower that closed the bead, trapping the wire. The tool that I came up with to install the wire is made from an old pair of needle nose visegrips and a small piece of the 3/16” x 1¼” flat bar. The top jaw was ground 1/8” shorter and the flat bar was spot welded flush with the end of the jaw so that the flat bar lands about ¼” from the end of the lower jaw. On the lower jaw, grind off the teeth so that the lower jaw doesn’t leave marks on the edge of the fender. See Figures 3a & 3b.

Figure 3a

Figure 3b
Now that you have the tool made up you will need to cut a piece of wire long enough to fit the whole length in one piece. You may have noticed when you took out the old wire that it still had memory of the spool that it was originally wound on. To me it indicated that the wire doesn’t have to be bent to fit too carefully. The tight corners and bends must be pre bent otherwise you will not get the wire to stay in the groove when you are assembling.
I started at the front of the fender but I don’t think it matters. Note in Figure 3c that I left a little extra wire sticking out. Getting started is a little tricky as you can see the wire isn’t fully imbedded but once you have it started it will go easily.
I’ve changed to a ball peen hammer as it has a little more weight to it, you can see by the reflection in the ball end that I’ve polished this hammer too. The hammer end has been ground slightly convex and the corner rounded and then buffed to a mirror finish. Even the dolly’s are polished. This is redone on an as required basis.
And again, as when you opened the bead it was done in stages, closing is the same. The first pass has to capture the wire. Work towards the clamp then move the clamp forward a few inches at a time, then go back and hammer the lip tighter to the wire. Remember that you don’t want to stretch the metal and by gradually closing the bead you shouldn’t stretch anything.
My vehicle had been in a couple of front fender benders and the nose of the front fender had a lot of work done on it. Someone got a little carried away with a grinder and vixen file and thinned out the leading edge. When I closed up the bead edge the lead edge cracked and now I have to weld it closed after the wire was installed. I’m using .023 and .025 wire that doesn’t generate too much heat. So you might want to do a close check on your fenders.
At this point you can do some fine tuning to straighten the edges of the fenders and complete the final shaping. Once complete, your fenders should now be stiffer.

Figure 3c

Figure 3d
You may find ways to fine tune my process - don’t be afraid to experiment.
Ron Heppner
Lions Gate Model A Club
Vancouver, B.C.