There are some basic hurdles placed in your way for such work: The bodyshell makes some of the screws (inserted into the edges of the plywood) inaccessible. Secondly, the rear bodywork was largely built around the boot side panels, and it is physically impossible to fit them in one piece without removing the bodyshell and other parts of the woodwork. If you split these panels into two parts, then you need to consider the load paths. In particular, they help to support the rear shelf assembly and roof, transferring those loads to the main sill boards and also the chassis. As the body/chassis twists, the boot side panels are placed under tension or compression.

Plywood

The original plywood used animal glue which is totally inadequate for the job especially when it gets wet and the plywood delaminates. Instead, get hold of some exterior grade plywood and be sure that that is what your supplier sends, as mistakes seem to be quite common. You can tell by looking at the colour of the glue, which is a very dark reddish brown. Also, make sure that the wood is a very strong hardwood, ideally birch. Plywood often comes in standard 8ft x 4ft (or 2440 x 1220mm) sheets and you can make a pair of boot side panels from one sheet by arranging them diagonally. The diagonal outer grain should run parallel to the sloping front edge of each panel. The bulkhead should have its outer grain running vertically, and since it is just over 4ft wide, you will need to get a sheet with grain running across its 4ft width.

Use a fine toothed saw to cut plywood. This takes longer but reduces splintering of the surface plies.

After making the components, the exposed edges should be sealed to keep out water and also to bind the edges to prevent damage/splintering. I think this is best done by using a fully waterproof adhesive such as "Aerodux" or equivalent. I believe it is also best to paint the wood frame, preferably with aluminium based primer and a tough gloss top coat (maybe a 1 part polyurethane?).

Plywood bulkhead renewal

Front wings, inner wings, steering column, and aluminium bulkhead need to be removed. If the bolts are the originals, then you might need to hacksaw through them. If the plywood bulkhead can be removed largely intact, then it can serve as a pattern for the new one. The little timber ribs fixed around the upper edges, have hidden screws inserted from the outside, covered by the body-shell. You will have to chisel out the plywood around them to release these joints. Also the top corners of the plywood hook over a pair of thicker rails, and these will have to be broken away.

If the old bulkhead is too far gone to serve as a pattern, then I might be able to help with drawings. I also plan to add photos to this site in 2010. A cardboard pattern to fit under the bodyshell, will help to get a perfect fit if the old plywood has crumbled away. The top corners that hook over that pair of rails, will have to be omitted, because the bulkhead cannot be slid into place otherwise (if the main bodyshell is still in place). Additional pieces can be added to these corners afterwards to fill in the gaps.

From the off-cuts of plywood, you can make new distance pieces that screw onto the front of the bulkhead, and the aluminium bulkhead in turn screws onto these with black japanned round-head screws.

Wing panels

Also from those plywood off-cuts, you can make new wing panels, that support the rear ends of the front wings. Take a bit of time to get the front wings to align well with the doorsteps and the doors. These little panels fit into slots in the vertical pillars, and are secured by three no.8 screws inserted diagonally. They are also held against the doorstep by a pair of no.10 screws. The surrounding timbers will more than likely need attention too, and you can usually splice in new pieces of timber to patch up the sill boards, door steps, pillars etc. Just be sure to use the best quality timber, ideally ash, with beech as the second choice. Glue and screw everything. Aerodux adhesive (or similar) will keep the water out, help prevent rot, and make strong joints. Please don't be tempted to substitude other materials such as softwood or metal! There are good reasons why certain hardwoods were used and continue to be used in coach-building. Metal in contact with wood is likely to corrode. Steel and aluminium are considerably stiffer than timber and so mixing metal and wood in a frame may over-load parts of the woodwork when the chassis/body twists. Most softwoods are not strong enough.

Boot side panel renewal/repair

The rear wings should be taken off by removing the large wood screws. The heads may need to be drilled off, or else you might be able to get pliers onto the heads to unscrew them. The steel inner wings (if there is anything left of them!) are fixed to the wheel arch with nails. Bolts pass through the lower end and through the plywood and into the chassis. Countersunk machine screws also pass through the inner wings and the plywood for the boot floor supports.

If the boot side panel was in perfect shape, then it would be physically impossible to remove in one piece while the main bodyshell is in place. My own original boot side panels were made to a surprisingly poor standard, with a very sloppy fit around the sets of 3 ribs that bridge the top edge of the plywood. This does at least make it easier to remove a rotted panel. It does also suggest that the cut outs in the plywood to accommodate those ribs, should be made overly wide in the replacement panel, to aid fitting it.

But a new panel will still not go into place as a single component, because the rear shelf and rear cross-member get in the way. If the panel has rotted at the bottom and looks as though it can be patched up, then that would get around the fitting problem. But this is not the ideal solution because the joints need to be very strong and rigid. The poor quality of the old plywood's glue means that any such joints will be compromised and may break up. This approach might also leave an unsightly join visible from inside the boot.

A better compromise (although I've not tried this myself), would be to make a complete new boot side panel, but with a separate detachable section at the top, just behind the rear shelf. That should permit fitting of the panel, and then fitting the top piece, and the joint will not be highly stressed or easily visible. This approach might also help with panel removal in the case of later crash damage (heaven forbid!). Make a cardboard template and check to see if it will slide into place. Even with this approach, it can be awkward wriggling the panel into place behind the brake back-plate. I wrapped part of the plywood edges with sticky tape to prevent damage.

If attending to any other wood rot, make particularly sure that the bottom corner joint (between wheel-arch and rear cross-member) is repaired so that it is strong. Also check to see if any of those sets of 3 ribs has snapped. The tops of the wheel arches may also have rotted. Water gets in via the rear corners of the side windows, washes out the animal glue, and leaves a free passage for more water. Water may also enter via the indicator slots. Make sure all joints in this vicinity are sealed up with water-proof adhesive. The main entry of water is passed the inner-wings when rust-holes appear in them.

There were two designs of boot side panel. The early ones (up to early 1950) had the axle cut-out extended rearwards to provide room for the lever-arm damper. In 1950, these dampers were discarded in favour of tubular ones fitted to an added subframe. So the boot side panel axle cut-out was changed, making it smaller, but with a slope to match the above mentioned subframe. Many earlier cars had their dampers upgraded to the tubular ones, and this left a larger gap through the boot side panel for road dirt and spray to get though. If you have such an upgraded car, it may, therefore, be worth changing the side panel to the later shape, assuming total originality is not your priority? The shape of the inner wing would have to be altered to match. If modified, it can still be cut back at a later date if one wants to get it back to original specification, involving removal of inner and outer wings again.

If you have a car that never had lever-arm dampers (i.e. there are no access hatches in the far corners of the boot floor), then take care that axle cut-out does not overlap the boot area and thus leave a visible gap into the boot.

It is worth taking time for a perfect fit of this component. Also, I drilled the bolt holes undersize and then filed them out to align perfectly with the holes in the chassis.

Important note: Make sure that the chassis is not twisted when taking measurements, doing trial fits, or aligning screw and bolt holes (and when finally gluing the panel into place). Have the car resting on its wheels, on flat ground, or if on stands/blocks, make sure it is supported close to axle level, and check for chassis twist.

Hopefully, you can use the old panels as patterns, and if necessary, add cardboard to complete the pattern if chunks of panel are missing. Again, I might be able to help with scale drawings if you have no data to work from. The right-hand panel has a recess to clear the petrol filler pipe. Clearance may be very tight, and my original panel was damaged by the pipe. For my new panel, I removed more material for greater clearance, and then glued a reinforcement piece of wood to the outer side of the panel.

The joint between the boot side panels and the chassis sides, creates a water trap, and direct contact between wood and metal is not desirable at the best of times. Oil and grease should not be used in contact with wood. Waxoyl can be used, and this is ideal for dipping the bolts in. Silicone-rubber might do the trick for sealing between the plywood and the chassis? Waxoyl may also be ideal for coating the steel inner wings where they touch the wood frame.

Where the boot side panels fit into a slot on the rear cross-member, there is a no.8 woodscrew that passes through at a 45 degree angle to fasten the panel down securely. This was fitted from the outer side, which is hard to get in or out without dismantling the entire back end, with body-shell removed! So, I've inserted mine from the inside, still at 45 degrees. A pair of no.10 screws hold the panel (rear end) to the wheel-arch, separated by a distance block. My distance blocks were not a snug fit against the rear cross-member, which creates yet another water/dirt trap, so it is worth modifying them for a better fit.

Hardwood repairs

For a semi-rebuild, access can be limited for some of the hardwood components. For those that you do repair, there is the question of whether to renew it completely or repair it. As long as the joints are done well, and the grain direction is favourable, then parts with localised rot can be patched up. If it is to be repaired, then there is the question of whether to cut out a minimum of material (in addition to the rotten wood) to preserve original material, or else to cut a lot away to simplify the repair. The first consideration is the strength of the repaired part and this has to be assessed in each individual case. If the part is curved, then a new repair piece spliced in, may help to avoid short grain weaknesses found at each end of a curved section.

Consult the previous page on restoration tips for advice on splicing in new pieces of timber.

There is also the question of whether or not to remove a wood frame part. If a joint is still firmly glued, then the joint itself should be sound, and the glue will help to maintain the alignment of the part if it is not disturbed.

In the photo shown here, the new pieces of ash are shallow in relation to the surviving original timber. They are accurately fitted (which takes time!) for a good glue joint, reinforced with stainless steel screws. These ash timber repairs were done without removing the components under repair.

Inner rear wings

These are made of a light gauge (20swg/0.036"/0.91mm) mild steel. I haven't made any drawings of these yet, but most of the required dimensions can be made from the wood frame. Its outer edge follows the wheel-arch, to which it will be nailed. Its inner/lower edge is mostly folded into a square channel to fit around the edges of the plywood boot side panel. Roughly cut tabs fold up under the main sill board near the front end, and under the wooden rear cross-member at the rear end. Each inner wing is made from two pieces welded together along their length. The photos below give some indication of the shape.

Rain water leakage

A common complaint from 2 Litre drivers was rain water leaking onto his/her feet. The rubber seal at the rear of the bonnet acts as a gutter, channeling water behind the inner-wings and onto the bottom of the plywood bulkhead to run down onto the road. AC pinned the rubber seal onto the top edge of some plywood distance pieces, but with the copper pins inserted through the bottom of the rubber seal/gutter. That allows water to pass into/onto the wood and drip onto the front floor panels. If the rubber is not fully sealed and stuck down, then not surprisingly, water gets through easily. Modern silicone-rubber sealants solve this and the fixing pins can be excluded.

Too much hot air!

Another old complaint is the amount of heat entering the passenger compartment, especially for the driver, although welcome in cold weather. On my car, there were no seals of any kind around the front floor panels, although any original seals might have been discarded? The aluminium bulkhead also lacked seals where it is fastened to the inner-wings. It should not be very hard to fabricate suitable seals, and possibly include ventilation ducts for the foot-wells for either warm (engine bay) or cool air. The brake and clutch pedal openings in the floor have foam-rubber sheet to reduce drafts. Similar treatment is provided for openings in the aluminium bulkhead for the accelerator and steering column.

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