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Trunk Lid Rust Repair
bad lid

By Roger Kizer

This is a common area for 1964 though 1966 Barracudas to rust and I have no idea why or how other than condensation builds up on the inside of the trunk lid, runs down to the bottom lip and just does its damage. Too many trunks are scrapped for this reason and not many left to fill the spaces so I decided to take on this challenge and repair the rust. Why not, I repaired all of the other rotted spots on the car already. The problem with my trunk lid is that it was in an accident. Its dented and dinged on the crease above the letters and it looks twisted sitting higher on the left side.

I figured if I was going to do this repair, it would be with a straighter starting point. I found a good trunk lid with some rust on the bottom lip, but the letters were gone and the holes filled in. I knew there would be some additional hammer work needed. After I ground out the bondo, sure enough, the letters were removed and the trunk dinged in to accommodate some bondo. There was also a small dent under the "P". All of these will be taken care of in the final body work phase after all the welding is done. I'll keep the old trunk lid as a spare, just in case, you know, if I bring home another project, someday. Man, this hobby really can be a sickness!

The same procedures listed here can be used to replace edges on doors and hoods, too. Please understand that I am not a trained bodywork specialist, I'm a do-it-yourself hobbyist and do the best I can. I have read many books on bodywork and am following the techniques in those books. Well, lets get started!

Here is my starting point. With all the paint and bondo ground off I can see all the damage.

New Lid

Here you can see the rust. Its worse on this end but there is rust on the right corner too. You can see the old damage I will repair later.

lip rust

I measured up an inch and a half and marked the lid all the way across as a guide line for the grinder.

Measure twice....

Using my 4 1/2 inch angle grinder with a cutting disc I carefully cut through the outer sheet metal along the marked line. Be careful not to cut too deep on the edges.

CUT!

When you are done with the cutting, the upper and lower sections will spread apart.

REMEMBER THIS! You may need to push the sections together when you fit the new sheet metal prior to welding.

the gap

Using a small pry bar start to pry the inner lip up and away. Take your time and do not force it. There are spot welds that will need attention and we do not want to damage the inner trunk lid.

pry up the lip

When it looks like this stop and address the spot welds. You can see the sections that are still stuck and need work.

pryed lip

Using the grinder cut around the weld like this to relieve the stress on the lip...

welds cut

...Then carefully grind the edge until you break through and can see the two separate parts. This will make it easier to pry the lip up around the welds.

gring the edge

Take the grinder and grind the inside lip off the corners. Now using the pry bar and a hammer, tap the lip off the trunk lid. If you run into any resistance, stop and use the grinder to loosen any stuck areas.

Remember, the goal is to remove the rotted lower lip without damaging the inner structure.

knock it off

And the lip is off. Don't toss the lip yet. We will need it as a template for the new sheet metal. Take this time to grind off any left over metal around the spot welds and clean up both sides of the inner lip with a wire wheel.

lip off

Clean up the sheet metal with a file to remove any loose metal. Now would be a good time to blow out any debris or rust floating around inside the lid.

new lip

I took the extra step of treating the bare rust with a spray rust converter. I did both sides of the inner lip and I sprayed as far inside the trunk as I could. Wait until it's dry and add a second coat. You do not want to do this repair again and now is the time to protect the metal. Other treatments like Por15 can be used as well.

rust fix

Here is the new sheet metal. I had the metal shop I purchased the strip from put a bend in it for me. There was no way I was going to get a straight bend myself.

new metal

I started by putting a flange on the top edge of the new patch so it fits under the the existing sheet metal on the trunk. This will allow us to weld the seam without blowing through and making the final body work a little easier for the novice.

You can cut the patch to fit to the cut edge and weld it that way, but I prefer to flange the metal. The flange pliers can be bought from Eastwood, but as always, I made mine.

flange

Get the hammer out, we need to bend the seam over to start the fitting to the edge of the trunk. Don't go too far, just enough to get it at a 45 degree angle.

Hammer

I have already made the the cuts necessary to fit the top edge into the trunk and left enough to run longer than the trunk is. I'll get to that later.

Starting in the center of the trunk, usa a hammer and dolly to peen the edge over flat. Work in small sections all the way down one edge. Don't try to get it flat all at once, take your time. Use a pair of locking pliers and clamp the new patch in the center as you work towards the outside edge.

Dolly

Once you get it close to closed, push one of the ends in tight to the trunk lip, clamp it down and continue to hammer and dolly the edge flatter and flatter.

one edge

Here is the other end. You may need some help to push this end flush to the trunk lip and clamp it down. Yes, it will bow a little but not enough to cause issues. We will work them out in the final body work later.

Continue with the hammer and dolly until the seam is fully closed all the way across the trunk.

other end

With the lip done it's time for the corners. Using the angle grinder I cut a arched line to the top corner of the bent lip and then cut the remaining excess lip off, leaving a flat flap to peen over on the end.

Take your time with the hammer and dolly. First, I used a "hammer off" technique to peen the lip up and over, then back to the "hammer on" to make the lip flat. If you cut all the way through during the removal stage like I did, make sure your edge is flat and straight. Repeat on the other corner.

corner

Here is the new edge.

Up until this point we haven't welded anything because we have to make sure the edge is straight. Measure at the ends of the trunk from the edge up the to body line on the trunk. If its off you still can adjust the edge to get it straight.

Finished pre welding

You can see how I cut the ends to fit under the existing trunk metal. I'll need to do a little extra welding to close the gap here. The corners will need to be welded and ground to get the radius correct. That won't be too difficult.

If you are not sure about the lip, you can take it to the next step and mount the trunk on the car to see how it fits before you weld. From this point all that's left is to weld it and do the body work. Stay tuned for part 2 of this project.

left edge