Introduction

I should mention that I am not a restoration expert. I have experience of a semi-rebuild of my 2 Litre Saloon, and am currently in the middle of a total rebuild. I have, however, gone to a lot of trouble over the years to try and establish the best methods of tackling a complex coach-built car, within the limitations of a home restorer. I hope to expand this section in the future.

Deterioration

The biggest source of trouble that led to the deterioration of old coach-built cars such as this AC, was the use of animal glue for the wood frame. This glue fails after contact with water, permitting joints to loosen and plywood to de-laminate. The frame becomes more flexible and this leads to cracking of the body panelling. Water gains free entry to the joints and rot can spread fast. This leads to further loss of strength and stiffness in the body frame, particularly when the boot side panels rot where they bolt to the chassis.

Most of the inner panels are of steel, and so these rust away. The underframe is very robust, but can still rust away at the rear end. The rear underpan catches dirt and moisture. The boot side panels (plywood) on my AC had no damp proofing to keep moisture off the steel chassis and the same was true of the rear wooden cross-member. Perhaps this was to try and obtain more stiffness for the rear chassis from the deep boot side panels?

The Challenge

Rebuilding wooden frame bodies seems to fill many enthusiasts with fear and foreboding! It is not especially difficult once you know about a few precautions and specialised techniques and tips. Basic woodworking knowledge is essential, but a high level of skill is not required. Patience, however *is* required! A large saloon car, coach-built, is a real challenge in terms of time invested, and will take a number of years if done in your spare time. Forget monetary values. If you like this fine car, then it is worth the trouble. You benefit from learning new skills and gaining satisfaction from a job well done. An added problem with the AC is that the original factory drawings for the wood frame were destroyed in a fire many years ago! My attempts to address this slight snag are covered in the section about the "Webmaster and his car".

Before You Get Started

Both before starting, and during dismantling, it is vital to build up data. This is partly photographic data of every detail so that you will know how to put everything back together again. Also, dimensions (especially the wood frame) need to be recorded. Dimensions of door surround, windows, wheel arches, length of scuttle, etc. etc. Keep in mind that the left and right halves of the body will differ slightly. Keep notes on joints, screws, fixings, routing of wires and pipes etc.

No Jigsaw Puzzles Here!

Contrary to popular opinion, a complex car body is not like a jigsaw puzzle. If you dismantle the wooden frame and reassemble it again (with or without repairs), its shape will have altered slightly. Doors won't close easily, while windows and panels might not fit. This is partly due to the amount of movement possible in each joint before gluing. Also, when removing major wooden parts, the remaining frame might sag or twist slightly. This will be worse if the car is slightly twisted to start with.

The solution is to make alignment jigs - just as AC used jigs during manufacture - and also ensure that the frame is not twisted. Some of these jigs will take the basic form of a rectangle made from strips of wood, with a diagonal brace to keep it rigid. These are tailored to fit into the AC's wood frame at various points, transversely and upright, to ensure that the framework is kept in place/shape while work progresses. Other types of jig can be made to align the wood frame on the chassis, so that it goes back in exactly the original position.

Basic Plan

Unfortunately, the AC was not designed with restorers in mind. Like most coach-built bodies, the wood screws are mostly inserted from the outside, and are thus covered by the bodyshell. The bodyshell, needless to say, is not designed to be removed. But for a thorough rebuild, bodyshell removal appears to be the only way, and some of the wood is inaccessible otherwise. Note that at this time, I have not refitted such a bodyshell - only removed one. So I am still looking forward to that daunting task! Annealing areas of the bodyshell would seem to be sound practice, but this may involve logistical problems. That is, the bodyshell is large and fragile to move when working on it.

Some experts recommend removing the wood frame from the chassis to work on. This might be fine for a small car, but for the AC, I prefer to keep it firmly bolted to the chassis until all wood repairs are done, and the whole thing is firmly glued and screwed. With only a single garage to work in, this was the only option for me anyway. It is, however, important that the chassis is kept flat and not twisted at all. If still supported by the wheels, you need to make sure that the springs are settled, (friction in the springs can keep one corner of the car too high) otherwise slight errors can creep in if the rear chassis is slightly twisted.

Rebuilding from the inside (bodyshell still fitted) is possible, but major modifications are required to the woodwork and originality is greatly lost. If making modifications, it is important to understand where strength is needed. With those points in mind, a partial wood frame rebuild is possible.

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