The Advantages of the Modern Coachbuilder (continued...)


Panelwork

Introduction
Materials & Methods
Metals Used
Restoring a Body
Building a Body
Windscreens
Hood Frame
Panelwork
The Advantages...

The handcrafted panelwork is a skill we readily accept in its own right as just one of the essential ingredients in the combination of special skills which produce a coachbuilt body. In real terms, it is a craft that established itself after the birth of the automobile and in a sense evolved along with it as the automobile developed. Most early car bodies, being direct descendants of the horse-drawn variety, thus carry with them most of the carriage builder's skills; with it came steam bent curved wooden body panels, wooden mouldings, leather fenders etc. Coachwork was usually more sparse and less demanding. It was only after manufacturers and designers fought for public recognition and to win the battle of the sales figures that coachbuilders saw the need for recognisable features and characteristics. There was a need to create desire, the desire to own, the desire to be different.

Ninety per cent of what we see initially, our first impression of an auto body, is the metal skin, the shape, its outline, its grace; in fact the statement that any car makes to us about what sort of car it is in the first instance is the exterior. Think for a moment about the different statements that various coachbuilders can make compare, say Saoutchik or Figoni and then compare again Hooper or H. J. Mulliner. The coachwork is an opportunity to sculpt with soft malleable metal which in itself becomes a work of art, the wood frame is to support the metal image created by the designer.

1912 Silver Ghost Mystery, coachwork by Holmes of Derby

The early transition from wooden to metal panelling is frequently a combination of both. It is quite usual to find an early 'D' front or tulip back open drive limousine constructed almost entirely of wood with wooden panelling, yet they are still only possible with aluminium front and rear corners.

With this and other attempts by coachbuilders to enhance an automobile's visual appeal came metal panelling. Most early panelling is of black iron or pure aluminium. Black iron panels are nearly always hammered into shape. The usual practice was to mark out the panel with a pencil into one inch squares, and then the panel beater would hammer out the panel onto a stake dolly with impeccable regularity to form the metal into a smooth regular shape using the squares as a guide.

From that point on, from forming simple, even curves, the skilful panel beater developed the process of producing automobile exteriors in whatever style the designer chose.

As you can imagine, with such a skill there are hundreds of ways of shaping panels by hand, and many craftsmen choose different methods to produce the same panel according to where their skills were developed.

From the panel beater's point of view, there are two types of panel - shallow, even panels such as door skins and bonnets, and the more shapely complex curves. Without doubt the best method of shaping up the shallow panels is by wheeling. Most enthusiasts will know of the wheeling machine but few will know how it works.

The basic principal is that the shortest distance between two points is a straight line. Now imagine a sheet of metal is a straight line. When the sheet of metal is placed in between the two wheels of the wheeling machine, the bottom wheel is adjusted upwards to squeeze the metal between the two wheels with a consistent even pressure. As the metal is passed backwards and forwards between the wheels ('wheeling'), the pressure squashes and stretches the metal. The distance beween the two points (the edges of the panel) then becomes longer, so the panel must then begin to bulge up or down. This is absolutely the same as hammering the black iron with regular blows mentioned earlier, but a much more controlled, even process, one producing beautifully smooth even panels.

The more shapely panelwork such as front and rear fenders and bulbous body panels will be a combination of wheeling and handbeating, very often deep shapely curves will be rough shaped with heavy pear-shaped bossing mallets, with the metal being beaten into shape on 'sandbags' - large round leather pouches made of tough shoulder hide and filled with sand or leadshot (size 6 or 7 for you duck hunters). With repeated blows, the panel can have areas of deep shape beaten into them before going on to the wheeling machine for smoothing out and more accurate shaping.

With deeper curves, the bottom wheel of the wheeling machine will be changed for a sharper profile. This will be necessary because of the tighter radius of the shapelier panels; also with a sharper radius, the contact patch between the two wheels is smaller, so as the metal panel is passed between the two wheels, the pressure is exerted on a smaller area of metal, causing it to stretch more. Hey presto! - shapelier panelwork. Of course it's not that simple. It's a skill which takes a good many years to perfect. The English wheel is an amazingly versatile instrument, and unless you've had a fairly gifted tutor, you will never really gain virtuosity in the craft.

Wheeling...

As with any other body panel, a front fender, say, will be made from several sections and welded together. Usually the sections for the construction are broken down to the most convenient number to make construction possible, but as a good guide to quality panelwork, a panel should be made from the smallest number of sections possible. If you have ever had the opportunity of examining the panelwork of say a French or Italian body, you will notice that they are made of many more and much smaller sections. Almost entirely this is due to the fact that the wheeling machine never gained favour much outside the UK and it is much more difficult to produce large panel sections by hammering alone.

When producing aluminium panels, the materials I like to use would be S1C, half hard bending grade aluminium. I would only rarely use soft grade metal, as although it is much easier to shape by hand, it deforms and dents just as easily, so wing tops - where the mechanics lean under the bonnet will damage and ripple much more easily. If you have an area in a panel to work which would be easier in a softer material, it is no problem, as with a good quality half hard grade aluminium, small areas can be annealed within a large panel very easily. With a welding torch, heat the area to be softened with a largish flame, but be sure to spread the heat evenly over the area to be softened and keep the flame moving. It's a simple matter to heat the metal to the required temperature and then to let the panel cool naturally with no quenching. You can measure the temperature quite simply by using a small piece of softwood about the size of a pencil sharpened to a long slender point at one end; as you heat the panel, rub the tip of the softwood sliver onto the panel. When the correct temperature has been reached, you can scribble your initials onto the panel and it will leave a brown inklike mark; too cool, and you'll get nothing; slightly too hot, and the tip will ignite like a match.

When sections are complete, they are ready for welding together. Nine times out of ten I will use oxyacetylene gas welding for this. It's my common practice to cut 1/8th inch strips of welding rod from the same sheets of metal that I am using for making the panels. This ensures that the filler rod is exactly compatible with the parent metal being welded. This is especially important when producing polished aluminium bodies, as you will often see a lighter stripe at the join in the polished metal panels where a dissimilar metal welding rod was used. Oxyacetylene gas welding will require a flux to be used - there are many products available. Manufacturers often recommend dipping the heated end of the rod into the flux powder, but this usually contaminates the tin of powder after a while, and you can only flux a couple of inches of rod at a time using this method. I prefer to mix up a small amount of the powder into a thick paste fresh every day using methalated spirit. This can then be painted onto the stick, touch the rod with the welding flame and the spirit will ignite the length of the rod, drying the paste as the spirit burns, and producing your very own flux-coated, fully compatible welding rods! Be sure that after welding you thoroughly wash the panel with very hot water to remove all traces of the welding flux which, as mentioned earlier, is extremely corrosive.

Where final assembly of body panels takes place with the last joints welded on the body, then I will use T.I.G/argon welding. This method doesn't use a corrosive flux - especially useful if you cannot gain access behind the panel on final welds - plus the instant heat of a high frequency electric heat source greatly reduces the damage to ash frames when welded on the job which a gas flame can do.

As a final tip before assembly of the panels onto your wood frame, examine all areas of your frame where there are screwed joints if there is a likelihood that any fittings fixed to the body after panelling, say screen posts or folding top mounts etc., might clash with screwheads underneath. Now is the time to remove a few individual screws and replace them with hardwood dowels. It can be so annoying to drill a hole through a metal panel into the wood frame, only to have the drill fall plumb on top of a screw head and wander off sideways into an oval shaped hole. Far be it better to replace a few screws with dowels.

If you cannot source any ashwood dowels, you can produce your own quite simply. For a 3/8th inch dowel, take some inch steel bar and drill a 3/8ths hole (or 5/16ths or whichever you require), do not remove the burr from the hole. Place the bar in the vice with the burr uppermost. On the bandsaw, cut some short square strips 2 - 3 inches long of ash slightly bigger than the hole, now with a mallet so as not to flatten the burr, this acting as a crude cutter, drive the short strips through the hole, each one driving through the last, and there you have it - screw length pieces of ash dowel.

Introduction
Materials & Methods
Metals Used
Restoring a Body
Building a Body
Windscreens
Hood Frame
Panelwork
The Advantages...

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