History, Construction & Reconstruction

Some Guesswork

I wrote the title of this section with good intent, but the reality is that we know very little of the history of our ShowMan’s wagon beyond what we can see before us. Everything else is conjecture!

As it was located on fairground wintering site, we believe the vehicle to be a Fairground  travelling van. From what we have seen in our researches, the design constitutes a short-lived transitional style in between those looking like the traditional elegantly decorated wooden-walled van with bow-roof and top vents, and the vans that essentially follow the same pattern as modern caravans with no top vents.  If we had to put a date on it, we’d go for late nineteen forties-early fifties, but we could easily be out by several decades!

Below is what we think is the (greatly simplified) trend of design either side of our wagon (which looks much like the blue and white van in style, but without the sky-lights).

Dorset steam fayre _8096054 JSL 514 - 1944 Scammell Pioneer "Nemesis" - Heavy Haulage + Showmans caravan @ Gaydon 2009 fairground wagon

The “Original” Build

This is based on the state of play when she arrived with us and, actually, we have no evidence whatsoever that this is anything like its original form. In trying to document the build of the wagon, this section and the following one have become a bit of a list, and in reality might only be of interest to me (and people contemplating similar herculanean tasks) so bear-with, or just skip it if it doesn’t float your boat.

CIMG5789-long

The Wagon is towed and pushed up the steep driveway.

The van was built on a steel trailer chassis with fixed rear double-wheeled axle with leaf-spring suspension, and articulated front axle. On her final “moorings”, the van has been lifted onto blocks under the axles next to each wheel. There are hose connections, presumably for air-brakes, and also a hand operated parking brake. In one of the underfloor lockers there is a large tank, perhaps diesel for generators or water; we have yet to determine. The wrought-iron eyed A-frame drawbar at the front, and the towing hitch on the rear, meant that we could push and pull the van into position. Presumably this meant that another trailer could also be hitched behind, though this would make for a frighteningly long vehicle. I wouldn’t say that we’ve done a forensic examination of the frame, but having spent a fair amount of time under the “skirts,” we have not seen any identification marks to help us with dating.

The superstructure was made from aluminium sheets over a timber frame and with fiberglass sections forming the curved roof ends at the front and back. The curved wall corners  were formed around plywood pillars and the pull-out extension was made from aluminium sheets attached to a steel frame which extends the width of the van. Panels were attached mostly with nails, although screws and rivets were also used, particularly on the pull-out section.

The floor was pitch pine  and the lockers that sit between the axles were floored in similar wood. It was generally in good condition, with the odd bit of rot where plank-ends met the outside or where water had leaked for example in the bathroom and where the bedroom shower had leaked. The external joists were another story, being in pretty bad shape.

Rotten floor joists

Although the floor was in generally good condition, the external joists were in need of some TLC

Internally the van was lined with a kind of formica-coated ply. This had done the job of forming a moisture barrier extremely well, and without exception had concealed the true horror of the underlying timber frame. It was only the places where the whole lot moved that gave an idea of the scene that awaited us. That and the pervading smell of rotten wood! The finish was dark wood in the lounge and lighter elsewhere.

The first panel is removed to reveal wet fibreglass and rotten wood...but no asbestos!

Wet, rotten and slimy, but at least it’s not asbestos! The first panel comes off.

The timber-frame itself was a surprise. Given the overall robustness of the caravan, and the quality of the floor, we had expected to discover fine coach-building work under the skin, but it was far from it. The removed panels revealed a hodge-podge mixture of new and old timber and planks cobbled together with bits added on where the frame didn’t match the holes in the aluminium paneling. Clearly it had done the job, so who are we to judge, and in a strange way it took the pressure off me in terms of being able to rebuild it.

As you might expect for a vehicle aimed at life on the road, many of the van’s storage/living fittings were built into the fabric of the structure. The bedroom had a built-in  single bed and wardrobe arrangement built across the back wall and a separate sink and shower, the kitchen had fitted units above and below the worktop, the bathroom had a full-size bath, the diner had a bench seat with storage below, and the lounge had a number of storage cabinets built around a stove hearth.

Heating had been provided by a stove in the lounge, with hot water and a couple of radiators running from a gas-fired combi boiler in the kitchen. All that remained in the lounge was the hearth and a section of flue, and the boiler was long dead.

From what we can tell, the wagon has undergone several incarnations. Along with the “use and reuse” nature of the wooden frame, there is evidence of the reuse of aluminium sheets (e.g. rows of holes no longer in use), and a whole set of roof-lights  or vents that are now closed over. The burgundy stripe was also once blue. Digging a little deeper, our guess is that the rear bedroom walls are the oldest; these were made from timber insulated with glass fibre. Moving forward to the lounge there was  a sudden change to the use of expanded polystyrene as insulation, and this was used throughout the lounge. We think that the pull-out extension was added at a later date, and the polystyrene marks the extent of the rebuild that was required at that time.

Our Re-Build

From our earliest contacts with the wagon, we were braced for a complete section-by-section dismantling of the walls to inspect what was going on underneath and to upgrade the insulation to Kingspan or foil backed glass wool sheets, and even before we took the panels off, we knew we’d have to patch the frame here and there. Most of the internal fittings would also need to go, either to create more space or because they were rotten (pretty much anything made from chipboard), or indeed both. It was our hope to be able to reuse most if not all of the aluminium sheets.

Today’s lesson is about Galvanic corrosion (also called bimetallic corrosion or contact corrosion). This is an electrochemical process in which one metal corrodes preferentially to another when both metals are in electrical contact, in the presence of an electrolyte (e.g. water). There is a scale which rates different metals as either anodic or cathodic, and when the different metals come into electrical contact the more cathodic one is prone to corrode, although this can be reversed to cause anodic corrosion if the size of the cathode is much greater than the anode. So now you know!

And why is that important? Well, as soon as we started taking the aluminium sheets off the frame, we noticed the extensive decay of the nails and screws holding the panels  in place. At first we thought this was just an indication of how wet the underlying wood was, but we then noticed that other nails holding the wood frame together, and not in contact with the aluminium, were in much better condition. Aluminium is one of the more cathodic metals, and the scales would predict that it would corrode when in contact with iron nails. However the size of the sheets compared to the small iron panel pins means that the  nails took the brunt of the corrosion. Which was good news for us, as nails are comparatively cheap to replace!

Grinding the rust off the pull-out frame

Cleaning up the framework of the pull-out (with fire-extinguisher just out of shot)

The story was not so good when we got to the pull-out extension in the lounge where the panels were attached directly to the steel frame. Here the anodic frame was much larger compared to the cathodic aluminium, and the corrosion of the sheets was much more extensive. We managed to reuse the walls with care, but looking up at the roof from inside was like a visit to a planetarium for a bit of star-gazing, and we had to concede defeat with that one.

As well as affecting what materials we could reuse, this issue also influenced the way we went about the rebuild. After a bit of research, we came across a design of blind rivet designed to attach thin sheets to fibrous materials e.g. wood. As they were made from aluminium, there would be no bimetal effect, and they could be easily drilled out if we ever needed to remove a panel. Perfect!

The pull-out extension was a bit more problematic as we were still attaching aluminium to steel, and our approach was to limit the amount of electrical contact as much as we could. The frame was painted with hammerite and covered with a polythene sheet before the sheets were placed, and although we used aluminium rivets to attach the sheets, they were separated from the frame with plastic rivet-liners. The roof, we replaced with glass; if star-gazing was order of the day, then you might as well do it properly.

Our notion of patching up the woodwork here and there was sadly misguided, and in the end we had to completely rebuild all of the external walls, and all of the roof. We framed the walls with T or L section pillars made from two tanalised slate bats screwed together, which gave the perfect depth for filling with Kingspan block insulation (we bought a pallet of seconds which suited us fine).

A mixture of new and old framing.

A reframed wall and new corner pillar in place, but the roof remains un-started.

For the roof beams, we made a jig reproducing the curve of the roof and used it to create laminated beams from thin strips of wood screwed and glued together. The steeper curve at the transition of roof to wall was achieved with purpose-cut blocks of oak to replace the largely “ply-and-offcuts” ones that we found in place. We made a template from one of the first ones we removed, and cut enough  oak ones for the entire van. Sadly, for some reason it seems no two were the same, and we spent the rest of the build “adapting” this valuable stock of wood.

Some early “unhappiness” getting multiple aluminium panels to fit back onto the first reframed area (the back wall) taught us an important lesson. We had naively started out worrying about such niceties as horizontal and vertical, but had not really understood the nature of the beast, in particular the fact that the whole waggon was seated on sprung axles. So, having set the vehicle flat on arrival, we then proceeded to gut the internals and remove walls, thus rearranging the weight distribution enough to throw all these lines off. This challenge only dawned on us when our first carefully mapped, measured and rebuilt wall proved to be completely out of line with the panels that had to re-attach. We quickly abandoned this approach, settling for perpendicular or parallel to the floor as our measurement of choice, and we tended to work one panel at a time, using the surrounding wall and roof panels as references for the reframing.

The floor was in largely in good condition, but needed the external joists replacing in places. on a number of planks the end sections nearest the wall were rotten, and water leakage had led to more extensive problems around the bath, shower, and in the doorway. The joists were replaced by tanalised timber, and the planks were patched with our own oak. The bathroom floor was then topped with marine-ply to give a good flat base for fittings and lino. Elsewhere, old pipework holes were plugged and the planks were sanded and varnished.

Floorboard repairs in the bedroom.

Our own oak floor-boards replace the rot from the old bedroom shower.

Given the open nature of the build, we guessed that the inside faces of cold aluminium panels were always likely to attract condensation, even if it was externally derived in the form of dew. With this is mind, the external faces of the timber frame were treated with creosote to help prevent rot, and then painted with bitumen to resist water. We always left at least one face of each piece of wood bitumen-free to allow the timber to breathe. Although there seemed to be conflicting advice, we opted to put the vapour barrier on the internal side of the insulated frame; our thinking being that any moisture from the living space would be less likely to get as far as a cold surface.

The inside surface of both walls and ceiling was lined with a polythene sheet as a vapour barrier, and then lined with ply. In some places, such as the bedroom and lounge, a tongue and groove wall was built onto this surface, but in other areas we routed a faux tongue and groove finish into the surface of the ply.

Tongue and groove cut into plywood

Faux tongue and groove on the kitchen ceiling

The fibreglass domes at either end were very fragile and sported multiple holes and tears which we carefully patched with car bodywork repair kits. They are not the smoothest of repairs, but once finished and painted they look ok.

The original lounge stove had been sat on a paving slab and largely enclosed within a wooden cabinet lined with asbestos sheeting. With the cabinet (and asbestos) long gone, we set about redesigning the fire-place for our log-burner. The wall in that section of the lounge was “double-lined  with air-space” with modern fire-board, and the roof around the flue was lined with similar. We opted for a double-skinned flue with a much lower and safer external temperature allowing closer proximity to combustibles. The fire itself was stood on a plinth made from rendered blockwork and topped with slate, all on top of a marine ply base to provide a level surface.

Fire-boarded caravan fire-place

The fire-boarded walls get ready for the stove.

In the bathroom, we felt that a bath would consume too much space, and so went with a wet-wall backed shower cubicle. We had a new gas boiler installed with a flow-rate suitable to match the good water pressure we enjoyed down at the van. Radiators were installed in each room.

Inside the wagon we tried to make use of our own wood wherever possible. Besides the oak-plank repairs mentioned already, we used oak, ash, Japanese larch and wild cherry wood, harvested and milled by our own fair hands, to create shelves, coat-hooks and window-ledges around the van. We also built the staircase and, favourite of all, the oak double bed with ash slats which had to be built in situ.

During the rebuild years, we were also involved in helping clear-out the cluttered garage of a relative. This proved a treasure-trove of interesting bits and pieces without a clear role, which is presumably how they ended up there in the first place.

Upcycled oak panels form the pull-out extension walls

Fitting the oak-paneling in the pull-out extension.

Amongst the finds was a complete set of solid oak kitchen cabinet doors, some of which we used for panelling the pull-out extension. With the addition of some interesting oak planking, the bathroom shelving was made from an old umbrella stand, and the bedside tables from old stools. Whilst making things from scratch is a great feeling, the repurposing of stuff that would otherwise end up in a skip is strangely satisfying.

The wagon was attached to a 16 amp caravan electrical hook-up which meant that we had to be careful with the appliances added to stay within the limits of the supply. All of the lighting was changed to low power or LED, and where there was an option,  gas-powered was chosen (e.g. cooker, kettle to sit on the hob rather than an electric one). The central heating system and hot water are also powered by a modern calor-gas combi-boiler.

And there it is. It took around three years (part time and with varying amounts of commitment!) to complete, and ran to about three times our original budget. Much of the budget increase was down to significant “mission-creep” as we realised that this could be so much more than just a shed on wheels. For example the plumbed bathroom and central heating were not part of the original plan.

Would I do it again? Probably, but not just yet!