Removing the Rear Panel
Figure 2
The rear panel on 4/4 Morgan's have not changed much since 1955, although different models do vary slightly. On V8 cars, twin fuel caps appeared and the rear panel on later Morgan's have flanges on the sides which wrap around the edges of the laminated wheel arches. The following text relates to the arrangement on my 1972 car, which uses aluminium half round strips to hold the rear panel in place. Nine screws secure each of the aluminium strips and to gain access to them requires rubbing down the paint which hides the filler covering the screw heads. A sharp spike can be used to dig out the filler to expose the slotted heads of the screws, which can then be removed along with the aluminium strips. When the strips have been gently prised off, a row of gimp pins securing the rear panel will be exposed. The pins can be prised out with a small sharp blade and wire snips. Underneath the ash rear bottom rail another set of screws securing the rear number plate panel and lamp bracket must be removed. Four 'lift the dot' and two 'durable dot' fasteners, which secure the panel to the ash frame rear top rail (see Figure 2), must also be removed. The fuel tank is not shown in Figure 2 for reasons of clarity.
The rear panel can now be released from the ash frame. The edges of the panel will have most probably corroded and although it may be possible to weld new strips of metal down the sides, it will be easier to replace it. The photograph in Figure 3 shows the rust on my own back panel when I removed it. The rear wheel arch side panel shown in Figure 2 protects the side of the laminated wheel arch. It is held in place by gimp pins. This panel will usually have corroded also, but is quite straight forward to construct. It overlaps a tongue on the end of the rear quarter panel. When this panel is being refitted, a little mastic on the overlap should prevent the ingress of water.
Making a New Rear Panel
Figure 3
If you do not feel confident to make a new rear panel, Morgan agents like 'Melvyn Rutter' will sell you a new one, but companies on the web like 'Metals4u' will supply you with a 2000mm x 1000mm mild steel panel for a fraction of the price. You will also require 2.5m of smooth steel 8 S.W.G wire and an 18x1220x2440mm plywood sheet. It may seem slightly daunting at first sight, but making this panel is not as difficult as you may think. I had never done any metal work since leaving school and I managed to make this panel on the first attempt and you can't tell the difference from the original. I must admit that the first panel I attempted to make was a simple triangular one that fits between the front end of the door rocker, the sill board and the lower part of the scuttle post on the ash frame. It was a disaster. I ended up with a piece of buckled metal staring at me from my work bench. Behind me was a gleaming rolling chassis with a renovated ash body, an immaculate rebuilt engine and suspension installed and I couldn't rebuild the body! There was only two things left to do. Go indoors and drink a few cans of 'Special Brew' and remember the car restorer's motto "Never give up". With a little research and determination, I practised various panel bashing techniques on scrap metal until I was confident to continue.
The Rear panel is a large panel to cut out, as you will see from the dimensions shown in Figure 3. Various plate metal cutting tools are available, the most common of which are tinsnips, Monodex cutters and nibblers. Tin snips are adequate to cut steel plate up to gauge 18 S.W.G (1.2mm), but they distort the plate, which should rule them out for cutting the circular hole in the back panel. Monodex cutters do not distort the metal and if you accidentally break the blade, it is replaceable. they remove a strip of metal a few millimeters wide, so it is essential to keep to the waste side of the line when cutting. A cheap nibbler drill attachment will speed up the work considerably. I prefer using Monodex cutters which are slow, but easy to control and use when attempting an accurate cut. A set of cheap panel beating hammers will be required. It is worth spending a little time polishing the heads, as every mark on the hammer will be transferred to the steel. Obviously NEVER use a panel beating hammer on nails etc. A set of panel beaters dollies (polished steel blocks of various shapes) and a rubber or hide hammer will also be required for sheet metal work. You may be thinking that it is not worth buying all of the necessary tools to carry out this job and decide to buy a ready-made panel, but it will be an investment if you are making the other panels when rebuilding your Morgan. You will also have the tools for the rest of your life if you look after them.
When you have all the necessary tools and steel for the job, a template of the old panel must be made. You can use cardboard or heavy paper, but you may have to tape smaller pieces together to obtain the required size. Whatever choice of material you choose, ensure it is securely taped to the old panel before tracing out the template. Do not forget to allow extra steel for a flange, which is required to produce a wired edge for the circular hole. This wired edge produces a neat finish and gives strength to the panel. The dimension of the flange must be 2.5 times the diameter of the wire used. Make the diameter of the hole smaller by 5 times the diameter of the wire. For example: The diameter of the hole in the old panel in Figure 3 is 670mm. If a 4mm (8 S.W.G.) diameter wire is used, the hole in our template will be 650mm (670 - [4 x 5mm]) in diameter. This will allow for a 10 mm (2.5 x 4mm) flange. If accident damage is the reason for replacing the rear panel, it may not be easy to produce an accurate template from the old one, so hopefully the dimensions shown in Figure 3 should be useful. Assuming this is the case, ensure the ash frame is in good condition and measure it to get the exterior dimensions for the new rear panel.
Having fixed the template to a new sheet of steel, mark out the new panel. If you do not already have a tungsten tip scribing tool you can purchase one on ebay for a few pounds. Straight lines are obviously easy to mark out, but the circular hole requires a little more care. You must first establish the centre of the circle. There are various methods you can choose from. I use the perpendicular of two chords method. I usually use a third chord to check the accuracy of the central intersection point. I then drive a nail through the centre point, to which I attach a length of non stretch cord of the correct radius minus 10 mm (2.5 times the 4mm diameter of the wire I used), to a scriber. It is essential to drive the nail into a wooden block on the other side of the steel panel to keep it vertical and stable. Having marked out the circle, a hole must be drilled just inside the circumference to insert the cutting tool of your choice.
Creating a Flange to Produce a Wired Edge
Figure 4
Having cut out the new rear panel, it is necessary to produce a flange around the circumference of the circular hole. I am not sure how the professional panel beaters at Morgan do this, but the following method worked well for me. There are three stages required to form a wired edge to the hole. These are shown in Figure 3. The steel panel must be kept flat when forming the the flange (Stage 1,). To achieve this I used two sheets of 18 mm thick plywood. In each sheet I cut a 670mm diameter hole (the same size of the wired hole in the old panel). The walls of the hole must be cut perpendicular to the surface of the sheets. I then placed the sheets of plwood either side of the panel as shown in Figure 4. They must be aligned with each other and concentrically aligned with the hole in the steel panel. It is important to ensure the flange is the same depth (2.5 x diameter of wire) around the complete circumference of the hole. 'G' clamps are used around the circumference to ensure the panel cannot flex whilst forming the right angle bend. I suggest a minimum of four clamps are used. Only one at a time is moved when producing the right angle flange. I used short 'G' clamps, but deep throat 'G' clamps would be the best to use, because they do not have to be moved whilst beating the flange over.
Forming the right angle bend is achieved by hammering the metal over gradually, working backwards and forwards whilst slowly working around the circumference of the hole. The metal will obviously stretch during this process and the 'G' clamps must be kept tight to prevent the flat panel between the plywood from distorting. DO NOT try to bend the panel with heavy blows in one place. If you do, the metal may crack. When panel beaters form complex three dimensional curves, they will often heat the steel and cool it slowly during the process. This anneals the metal, making it soft after hammer blows have hardend it. When the right angle flange has been finished and the 'G' clamps have been removed, do not worry if the panel distorts and will not lay flat. This happened to my panel, but it became flat after forming the wired edge.
Finishing the Wired Edge
Figure 5
When a right angle flange has been achieved, it is time to insert the wire. This process requires laying the panel on a flat, non flexible surface. I waited for my wife to go out and used the kitchen floor. The surface was flat and covered in thin Marley tiles. It turned out to be perfect for the job. Stage 2 in Figure 3. shows 'trapping the wire'. Cut a length of 4mm wire slightly short of 3.142 x diameter (pi x D) of the hole. It should only be two or three millimeters short, because when you finish trapping the wire and find it is too long, it will be difficult to cut without damaging the panel. I clamped a length of wire to the flange and ran it round the circumference before cutting it. A rubber mallet is best used at this stage to prevent accidentally bruising the panel with a panel beating hammer. The procedure used to trap the wire is similar to forming the flange. Bend the flange over the wire working back and forth with gentle blows until the wire is trapped.
Stage 3 in Figure 3. is shown in Figure 5. I used a polished panel beating hammer which I slid along the surface of the panel, but a polished steel dolly will work as well. So that I didn't distort the circle, I made a DIY dolly shaped from a piece of ash 750 x 170 x 25mm and a 2mm thick length of steel. If you have successfully reached this stage your panel beating skills will be good enough to finish the wired edge.
Removing and Fitting the Filler Neck
The filler cap neck can be removed from the old panel and refitted to your new one. Remove the filler cap and heat the old filler neck with a blow torch (NOT whilst the rear panel is on the car!). The solder around it will melt. Whilst wearing welding gloves, remove it with a pair of pliers. Remove all traces of paint and rust with a wire brush attached to an electric drill. The template made to cut out the rear panel should have all the hole positions marked on it. Measure the diameter of the neck hole on the old panel and using a steel hole cutter on an electric drill cut the appropriate size hole in the new panel. The hole in my own panel was 57mm in diameter as illustrated in Figure 3.
Soldering the neck to the new panel is straightforward. Body solder should be used and the instructions for use carefully followed. I must admit that I used plumbers solder along with the appropriate flux. The neck and area around the 57mm hole were thoroughly cleaned and sprayed with an electronics cleaning fluid to remove any grease. I then coated the areas with flux and placed the neck in the rear panel and heated it with a blow torch, whilst feeding solder to the joint, in the same way as joining household pipework. When the job cooled down, the area was cleaned and a phosphoric acid based anti rust chemical was applied. I am told that plumbers flux can cause corrosion, however if it is thoroughly washed off after soldering, then treated with a phosphoric acid anti rust product, there should not be a problem. I painted the car nearly thirty years ago and it has not corroded yet. It is important not to use too much heat whilst soldering, as it could cause the panel to distort.
Refitting the Rear Panel
Figure 6
After gently curving the panel over the frame, the flange at the top edge must be formed and anchored by four "lift the dot" male fastners. Their position is critical, as they must align perfectly with the "lift the dot" female fastners on the hood. The bottom of the frame is folded under and fixed by screws to the rear bottom rail. When the panel has been fastened top and bottom, lay the aluminium strips in place. Carefully align them and mark their screw hole positions on the rear panel. Remove the strips and secure the edges of the rear panel with gimp pins, avoiding the hole positions. Use stainless screws to fix the aluminium strips in place. Before the rebuild, the paint cracked along the junction of the strips and rear panel on my Morgan. To prevent this from re-occurring I bedded the aluminium strips on cellulose filler. The heads of the screws will also need filler over them. It must be rubbed down to a perfect finish before painting.
