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In general, the construction is orthodox, although the wooden main bearers are no longer in commercial fashion in these days of cheap rolled channel-steel; however, they were chosen here to save weight and to facilitate home construction.

So far as the woodwork is concerned only two joints - the halving joint and the plain mortise-and-tenon joint are needed. An hour or so spent in practicing these in scrap timber will be well worth while. (See Fig. 8.)
Most of the metalwork consists of cutting angle-iron, drilling it, and bolting it together ready for welding. Such welding as there is should be carried out by a competent engineer.

Proprietary parts have been kept to a minimum so far as possible in order to keep costs down. Apart from small fittings of a general ironmongery order, only the corner jacks and the all-important ball towing-hitch must be purchased. If expense is no object, then such items as proprietary window frames, sink-unit and Calor-gas fitting will save time and improve the van quite a lot. However, some modification of the plans shown here will be necessary to accommodate the stock sizes of such fitments, they should thus be carefully thought about before building begins. Indeed, an intensive study of caravan periodicals and accessories catalogues is an essential preliminary to any caravanning venture.

There is some prejudice against "non-proprietary", or "home-built" vans, as so many of these are badly designed and worse constructed. Many site-operators forbid such vans entirely, whilst others insist on a superficial inspection. It is as well, therefore, to ensure that only the best is good enough, so far at outward appearance is concerned.

Only sound work will suffice in the chassis. A poorly made chassis will, apart from being a possible danger on the road, be a constant source of trouble in towing, leading to all sorts of misbehavior on the part of the van, which makes driving sheer hard work all the time.

Some home constructors may prefer to save time by purchasing a ready-built chassis, but this will run to considerable expense.

The wheels of the caravan described here were adapted from an old car front axle as follows.

First, all extra metal in the form of track-rod, shock absorbers, etc. is removed. The wheels are then lined up with a very slight toe-in, and the king-pins are welded-up solid.

The axle is then cut in the middle and extended to give a track between tire centers of 5ft. 6in., by boxing across the center with two pieces of angle-iron welded together and to the axle ends. (Fig. 2a.)

For steady, stable towing a wide wheel-base is necessary, with as great a distance as possible between the springs to avoid "top roll". (Fig. 2b.)

These are removed and stripped. They should be cleaned, reset and rebuilt with an extra leaf or two to a total of 9 in. X 3/16 in. The longer the springs the better.

As they are usually set at an angle on car front wheels, the old bolt holes on the perches should be welded-in, and new holes drilled so as to line up the springs at right-angles to the axle. The minimum distance between the springs should be 3 ft. 2 in. If the spring perches can be shifted wider apart it is certainly desirable to do so, but this may not be possible on cranked axles.

On straight axles, the springs can be reattached below the axle (underslung), so that a few inches of height reduction are obtained. A low center-of-gravity is useful for stable towing.

It will be as well to strip and regrease the wheel-bearings and to attend to the brakes (which should be of the cable-operated kind) to see that the linings are good and the action free in operation.

Tires need not be new, but should certainly not be smooth. In spite of rumors to the contrary, caravans do get punctures and bursts, and as no "spare" is carried as a rule, such mishaps can be embarrassing and involve considerable delay!

The axle and brake drums can be smartened up with a coat of bitumen paint, and the springs can be sprayed with penetrating oil.

Those consist of two soft. 10 ft. 6 in. lengths of 3 1/2 in. X 2 in. straight-grained prime ash. They must be free of all knots and blemishes, and it is worth paying a little extra to get the best timber. The size given is quite the minimum, and due allowance for planing must be added.

After shaping, the bearers are bolted on to the springs, using 3/8 in. diameter coach bolts with extra nuts as lockouts. (Fig. 3.) It is important to mount the rear scroll with its shackle high, remembering that it will settle under load. The bearers should be parallel to each other, and should be braced apart until the flooring is secured. They should also be levelled and supported on blocks until this is done.

Body Frames

All body frames are built from prime ash. The joints consist mainly of straightforward mortise and tenons at "T"-junctions, and cross-halvings at "through" points. All are glued with a waterproof resin glue, and secured additionally with a 3/4 in. long No. 8 countersunk steel screw.

The end bends are made by soaking suitable lengths of timber in a water-butt for at least 48 hours. Each is then cramped on to a 1 in. thick oak board shaped to the required curve, and is left to dry (fig 7.). Up to a week may be required to achieve the desired curve. It is important that all ten bends must match up, and as they are made, they should be lashed together and stored carefully on end until required.

Except for the spacing of the upright to allow for the door, both side frames are identical.

It is as well to cut all timber to length and number each piece as indicated in Fig. 9a. Then all parts which are to be of the same dimensions can be placed together and marked-out in one operation, thus ensuring identical accuracy for all floor and middle lengths, uprights, corner bends, etc.

Note that the corner bends are fitted into mortises cut at the necessary angle in the floor-lengths; the surplus is removed after fixing, which is easier than trying to cut true "bridle" joints as such.

Assemble all joints temporarily to check their fit and the truth of the whole framing. Then check the side frames together to see that they are identical and quite flat.
The end flames shown in Fig. 9b present little difficulty. Again, every care most he taken to ensure that they are identical with each other.

The completed side frames are coach bolted into position on the floor edge; the bolts, of course, pass right through the end supports under the floorboards. The frames will require strutting temporarily to prevent them from waving about.

The end frames are similarly bolted down.
The tops of the side-frames have to be nipped in" two inches on to the headboards of the ends This places the side under slight tension, and helps to give rigidity and stability.

The middle spars of the end frames are attached to the corner bends with small, right-angle brackets, as can be seen in Fig. 9b. This saves cutting an awkward joint which might weaken the bend.

The three roof bends can have their curves shaped whilst the sides are being made, by wetting them and bracing them over a pile of bricks. It is not essential to do this as the roof curve is quite a small one, but it does help to reduce the tension.

The rafters are spliced to exactly the same angle as that of the end frame heads (Figs. 9b and 10). Then the ends of the rafters are halved and screwed on to the side frame roof bends. The rafters should be braced temporarily at their centers until roofing is completed.

The roof bends are set down into their sockets, being held with cramps until the screws are put in. It is as well to offer everything on screws only at first, leaving the final gluing until all adjustments have been made.

At this stage the Pram appears unduly fragile and not very rigid, but the application of the skin will soon correct this.

On the van shown, the skin is 1/8 in. thick tempered hardboard, which is entirely weatherproof in itself and has a long life.

Hints About Hardboard

A few general points about the fixing of hardboard will be found useful. Each board should be well soaked with water for at least 48 hours; the backs should be sprayed quite wet, and the boards stored back-to-back. This treatment, together with adequate fixing battens (the recommended distance is 1 ft. 3 in., but the 1 ft. 6 in. of the framing seems adequate), will help to prevent distortion. The best nails to use are the special hardboard nails with square shanks and "lost heads" made in coppered steel. They should be used at 3 in. to 4 in. intervals, and fixing should begin at the middle of each panel, working outwards to the edges and corners, making sure that all kinks are removed and that the work lies flat. Panels should not butt up tight against each other; a gap of 1/8 in. is permissible.

On the caravan, all hardboard edges should be bedded on to a good layer of mastic sealer, and all points filled with this substance well pressed home.

Before painting, the hardboard should be primed with special hardboard sealer paint. All nails should be driven flush or a little below the surface. All holes and blemishes should be stopped up after priming (putty will do) and rubbed down well.

Bearing in mind these general points, the skinning of the caravan will present few problems. The van shown was skinned with large surfaces for quickness, cut from 12 ft. X 4 ft. sheets. Apart from some waste involved at the curves, this method has shown no drawbacks, although the use of smaller sheets may be more economical. However, the large joint-free surfaces are certainly neat and watertight.

The Sides

The bottom side panels were put on first, having been offered to the framework for careful marking out. The top sides followed the windows being cut out beforehand. Then the ends were dealt with, being allowed to overlap the sides as the corners.

The roof was put on in two pieces, these being offered to the job, marked off and cut. The first piece is fairly easy, being adjusted to the middle of the center roof bend first and trimmed off at the edges after fixing. The second piece has to be adjusted to give a neat joint against the first at the center. This is best done by trial and error; the hardboard is easily cut and planned. Again, it is better to allow the roof to overhang at the eaves and to make this tidy after fixing. All sharp corners should be glass papered off, and all nails made flush before applying the roof canvas.

This is plain canvas and need not be of exceptional quality. It should be 4 yds. long and 6 ft. 6 in. wide. From one end strips 4 in. wide are cut, which are used first to seal the central joint, and any others if the roof has been put on in smaller sections.

The canvas can be fixed either with an adhesive, or bedded down on to wet paint. A liberal coat of either is applied along the joints, and the canvas strips are pressed firmly into place. When the sealing strips are dry, the main canvas is rolled and placed conveniently at one end of the roof. An area about 1ft., or so, wide at a time is painted with adhesive and the canvas is unrolled on to is, being pressed down and smoothed to remove wrinkles, before proceeding with the next area. The canvas should not be stretched tight. as it may split as it dries.

Any surplus canvas is trimmed off so as to leave an overhang of about 1 1/2 in. This is turned under and pressed on to fresh adhesive at the eaves, being fixed with copper tacks at 3 in. to 4 in. intervals. At the ends the canvas is taken right under the overhang, and is glued and tacked into the finishing strips.
When dry, the canvas is given a priming coat of lead-based paint as soon as possible. This may be followed with as several coats at the time of painting the whole van.

All surplus spars across door and window spaces should be cut away, and the inner edge of the spaces rendered smooth.

The spaces for the door and opening-windows should be primed and any holes stopped. They may then be undercoated to help seal the hardboard. One excellent finish for these edges is to glue strips of Formica along them.

The windows are simple enough, being plain, rebated soft-wood, with dowelled bridle-joints at the corners, as shown in Fig. 13. The hardwood glazing strips are fixed with raised-head bronzed screws, using mitered corners as shown. It is well to make up the whole window before glazing. This is done with 24 oz. glass on ordinary linseed putty, and it is necessary to prime all parts where the putty is going.

The fixed-window frames are nailed into place before glazing, and the opening-windows are best hung without the glass. If the frames have not been made too tight little difficulty will be had with fitting these.
Each of the opening windows requires two friction stay sets and at least one screw-up type of window-fastener of the type shown in fig. 14

The bottom door is a plain panel of hardboard on softwood framing. The upper door is glazed and is made from rebated softwood with dowelled mortise and tenon joints. Both are hung on ordinary steel flap back hinges which are allowed to protrude about 1/2 in. so as to swing the doors clear of the van. The middle joint between the doors is made up by false rebates nailed on (Fig. 15).

The "J"-type roof guttering is screwed on to the roof canvas overhang, being set on to half-dry paint.
The aluminum storm-strips over the opening windows are similarly fixed, together with those at the doors.

all bright aluminum waist and corner moldings are screwed on to wet undercoating any surplus being carefully rubbed off. Naturally, the more care that is taken over the painting, the more professional will be the final result. Plenty of patience, thin coats and good rubbing-down in between will give the best results.

No one interior layout is entirely satisfactory to every enthusiast, and as this part of the van is so dependent on personal choice, only general guidance is given (Pics. 16 to 20).

In this small van with its light construction, the wardrobe is essentially part of them main structure and helps to brace the roof as also does one side of the cooker unit. It is desirable that both of these should be kept fairly central, within six inches or so one way or the other. The dimensions otherwise are not critical.

All furniture is permanently fixed and is built on to existing mainframes wherever possible to save weight. Softwood framing 1 in. x 3/4 in will be found to be adequate for most pieces, being paneled with lightweight hardboard (nominally 1/16 in. thick or 3 mm. ply).

Doors are framed-up in the simplest possible style, use being made of corrugated box-fasteners rather than complicated joints.

Walls are lined with 3 mm. ply; one of the pinky colors such as Japanese lauan, or gaboon looks well and is relatively inexpensive. It may be left plain or lightly toned with polish. It should be fixed with small brass pins.

In small vans it is advisable to keep the interior light in finish. The roof should be painted dead white, and all interior woodwork and hardboard should be lacquered in pale tones - birch grey is very pleasant - perhaps relieved occasionally by some brighter contrast here and there. Useful ideas can often he obtained by inspecting commercially-built caravans.