Phunkie Project Portafold (caravan!!)

[phunkie hiboy]

Talking to Andy today, at the Windmill rods and chops meet, and he suggested that some of you guys out there might be interested in this restoration build up.
Well here goes, what is a Portafold caravan? It's a lightweight, fibreglass, folding caravan, weighs in at 10Cwt in old money and has been known to have been towed behind a trike (you can tow them with anything upwards of 800cc. They were manufactured between the late fiftys to the early sixtys in Fareham, Hampshire. They do have quite a following in the classic car and hot rodding circles. So here's what one looks like .............

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

So we have purchased one of these after getting soaked last year at Beaulieu, when the tent started to leak!!
We have found that it needed more work than was originally thought, so with a debut at the Victory Wheelers, South Coast Internationals in June, we'd better get going.

I appologise in advance to those on here that have been following the restoration on another channel 

[phunkie hiboy]

Well, this is it, the Phunkie Project Portafold thread.
Collected the Portafold from Kidderminster on a Friday in late July. This is it as it arrived.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

The following day it was inspected, to see what was required to get back to a good working caravan. Unfortunately, due to repairs to be done, it will require a full restoration!!
So now we need to strip it down. First to remove the roof. The outside has many spiders in the fibreglass, there is a huge sag in the rear of the roof and inside it has some coating that has started to peal off.

Phunkie Project Portafold (caravan!!)

 

Phunkie Project Portafold (caravan!!)

[phunkie hiboy]

Now the roof is off, the ends are removed by drilling out the rivets from the hinges.

Phunkie Project Portafold (caravan!!)

The same with the sides, after removing the strip of sealing tape.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

We’re leaving all the parts on the ends and sides until they are stripped to repair.
As far as we are aware the wall coverings and cushions are the originals, however the wall coverings have been painted with something and as a result will be replaced at a later date

Phunkie Project Portafold (caravan!!)

All the lights and fittings are removed from the main body.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

[phunkie hiboy]

Now what is left is wheeled outside and raised using the jacks, all the chassis mounting bolts are cut/ground (far too rusted using spanners/sockets) and the chassis removed.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

At this point the main body was turned on it’s side and the jacks removed, using the same method as the chassis bolts.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

OK, the Portafold is now just a selection of parts as it would have been back in 1970, when it was assembled by, possibly a guy called S.Challoner, at the factory. On a lot of the construction of this type back then, the builder used to sign their names somewhere.
It’s now close of play on Saturday, a good days work. Oh, I’d better put the hinges in a bucket of penetrating oil to soak.

Phunkie Project Portafold (caravan!!)

Next time, it’ll be time to work on the chassis and jacks.

[phunkie hiboy]

OK, so before I start on the metal bits, I cleaned and pressure washed off the underside of the main body to see what repairs are to be done on the underside.
Before clean,

Phunkie Project Portafold (caravan!!)

After clean.

Phunkie Project Portafold (caravan!!)

Now the thing is clean it’s apparent that there a large number (23) of “drainage” holes, that have been drilled in the main body floor, to be filled/repaired.
Also there’s damage on the front on the nearside from a reversing “jack-knife”.

Phunkie Project Portafold (caravan!!)

Along the top side edges of the main body, where in production extra gelcoat was painted over the original due to the mould in that area being damaged and worn. This now peeling off.

Phunkie Project Portafold (caravan!!)

There is an inherent fault in the shape of the storage bin holes, in that the holes are cut square which results in cracks radiating from these corners. Whenever square openings are cut, in just about any material, the corners need to be radiused. This spreads the load all round the corner, is general engineering practice and would have alleviated the problem we have here. Every single opening in this Portafold is the same and all require attention.

Phunkie Project Portafold (caravan!!)

Some of the strengthening under the seating areas has deteriorated badly resulting in large cracks and sagging of the seats.

Phunkie Project Portafold (caravan!!)

[phunkie hiboy]

All the holes in the main body floor are sanded on the inside and fibreglass mat and resin are laid on to seal the holes from the inside. The split at the front is sand inside and glassed over.

Phunkie Project Portafold (caravan!!)

The front mount to the chassis strengthening panel (wood) has collapsed on one side and the layers of mat are secured to nothing.

Phunkie Project Portafold (caravan!!)

This is cleaned up and mat and resin layered up over the wood an finally over the whole area making sure that it extends at least a couple of inches out side of the wood.

Phunkie Project Portafold (caravan!!)

In between repairing the body items, due to the drying times of the fibreglass, I will be looking at the chassis and jacks.
First the chassis and brakes. With the brake drums removed, the shoes are checked for wear and cleaned with emery paper. The drums are also cleaned, on the braking surface with emery.

Phunkie Project Portafold (caravan!!)

As every thing in here is serviceable the drums are refitted.
The chassis is in good condition

Phunkie Project Portafold (caravan!!)

 and just requires a sanding down and a repaint with chassis paint.

Phunkie Project Portafold (caravan!!)

[phunkie hiboy]

So onto the jacks. This shows two jacks, but the same process is carried out on the other two.

Phunkie Project Portafold (caravan!!)

Strip these completely, removing the fixings.

Phunkie Project Portafold (caravan!!)

To make it easier to refit the units, the fixing holes are countersunk

Phunkie Project Portafold (caravan!!)

 and fitted with countersunk bolts, tack welding to secure and grinding clean.

Phunkie Project Portafold (caravan!!)

All parts are then cleaned, sanded and painted with chassis paint.

Phunkie Project Portafold (caravan!!)

And assembled.

Phunkie Project Portafold (caravan!!)

Whilst waiting for fibreglass to ”go off” I put the handles on the polishing mop and also the front roof positioning brackets.

Phunkie Project Portafold (caravan!!)

[phunkie hiboy]

So now, back to the main body and strengthening the seating areas and radiusing the corners of the storage bins.
The strengthening of the seating areas is achieved by glassing “D” shaped “rope” within the layup.

Phunkie Project Portafold (caravan!!)

 Unfortunately the resin has deteriorated to such an extent that there is no support at all. Added to this is the fact that the strengthening is not long enough, stopping level with the edge of the storage bin holes. This results in more strain in the badly engineered corners.

Phunkie Project Portafold (caravan!!)

The seating is pushed back into position using a scissor jack. The missing “rope” is replaced and laminated in. At the same time fibreglass is layered under the corners of the bin holes.

Phunkie Project Portafold (caravan!!)

After the laminate is set, the corners and splits in the seating areas are ground out. These areas are laminated to the required height.

Phunkie Project Portafold (caravan!!)

After drying the corners are cut out using a hole saw, and using an airsaw the bits between are cut out. All the repaired areas are sanded flat and then skim filled and finished for priming.

Phunkie Project Portafold (caravan!!)

This operation is pretty time consuming, so it’ll be a while before all the storage holes are repaired.

[phunkie hiboy]

Just a quick update, nothing much to show as the repairs to the openings for the storage areas are still ongoing (real work seems to be getting in the way!!).
In between laying up fibreglass, I’ve been able to spend some time on the hinges. There was probably a 50/50 split on seized and partially seized and one completely broken.
Last time they were mentioned, I had put all of them in a bucket of penetrating oil. They soaked for about two weeks.
It was then just a matter of “working” them, untill they were free. After which they were cleaned to get all the verdigris  off.

Phunkie Project Portafold (caravan!!)

Attention is now turned to the broken hinge. The actual fault is that the pin, through the middle is broken. The original pins are steel and 1/8” in diameter. So after sourcing a piece of steel rod that size, it is cut to length (a little more than the length of the hinge). The parts of the broken pin are carefully drifted out with a compatible parallel punch. Care must be taken to support each part of the hinge whilst this operation is carried out. I fabricated a small fixture, held in a vice, to do this.

Phunkie Project Portafold (caravan!!)

The hinge is now assembled with the new pin and the pin carefully peaned over at both ends, hence the slight extra length of the pin, and cleaned.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

As we are likely to tow the Portafold with our Peugeot 306, as well as the roadster, the law states that trailers being towed by post 1972 vehicles require the fitment of at least one rear fog lamp.
So rather than just bolting on some non descript bulky lamp that looks like it was just screwed there, it was decided to install some neat lamps that pretty much fit in with the general look of the rear.
The lamps being used are some I found a while ago, when sourcing fog lamps to fit to import cars (part of my day job). They are a readily available Hella lamp that measure about 2” across

Phunkie Project Portafold (caravan!!)

First, some mountings needed to be fabricated. So I found a piece of tube the right diameter and made a collar to fit to produce a top hat shape. This was used to laminate around.

Phunkie Project Portafold (caravan!!)

The end result was then put in the lathe and turned down to end up with the required depth and diameter mounting.

Phunkie Project Portafold (caravan!!)

A decision  was then made where to place them, to not look out of place and the holes drilled for the mounts.

Phunkie Project Portafold (caravan!!)

The mounts were then fitted and orientated to the correct angles, the lamp has to be fitted vertically.

Phunkie Project Portafold (caravan!!)

It was then just a job of laminating the inside.

Phunkie Project Portafold (caravan!!)

And then on the outside.

Phunkie Project Portafold (caravan!!)

Finally, the outside was filled and shaped and covered in some hand painted two pack primer (this protects the “repair” from moisture).
This will be sanded down again when the final priming, to paint, takes place.

Phunkie Project Portafold (caravan!!)

[phunkie hiboy]

It might be worth noting that although I do have my own small workshop with all its facilities, apart from maybe the turning of the fog lamp mounts, all the repairs so far could have been carried out by any of you in the garage beside your house.
Whilst continuing with the storage holes, some times there is amounts of laying up resin over and so as not to waste it I look for other items in need of repair.
The small lower door had been backed into something resulting in a dent/split in it and where the number plate had been bolted on, it had crushed the inner and outer skins together.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

So the first thing to do was remove the hinges. As the first securing bolt broke off, making a removal job difficult, I drilled the other three bolts out through the heads which enabled me to get a good “centre” on the bolt.

Phunkie Project Portafold (caravan!!)

 Small drill to begin with then out to 5mm, this enabled me to tap through into the strengthening steel with a M6 tap.

Phunkie Project Portafold (caravan!!)

Unfortunately one of the holes didn’t want to play ball, so it was drilled out to take a M6 Rivnut. This is a threaded sleeve installed just like a pop rivet.

Phunkie Project Portafold (caravan!!)

And this is it after installation (sorry about the blurry picture, but you get the idea).

Phunkie Project Portafold (caravan!!)

Now onto the fibreglass repairs, couldn’t get into the rear of the dent so it was either separating the skins of the door or cutting a “panel” out on the inside. The latter was chosen and carried out, this will be covered by a fabricated panel, secured by clips and trimmed in matching material to the interior.

Phunkie Project Portafold (caravan!!)

Laminated fibreglass was then added to the inside of the repairs. One of the holes for the number plate securing was distorted so badly that over the years it had set in its collapsed position. Some times this can be helped out with some heat from a hot air gun (not too hot though, because this laminate is really thin!!).
As in the other repairs, the damaged areas were sanded back to the new laminate and Fibreglass and resin added as necessary and sanded back when dry. Body filler was then added to fill any dips or pin holes and sanded.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

Finally, to protect the “repair” from moisture, hand brushed two pack primer was applied.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

This is now ready to sand and prime with a two pack primer when everything else is painted.
Back to the main body, finally managed to finish the storage holes on the righthand side.

Phunkie Project Portafold (caravan!!)

Whilst carrying out the repairs on the storage holes I was thinking about the electrics we would be using. There is obviously wiring for the rear lights. We are going to fit a hookup, so that has to be a consideration and we need some lighting, to be run off a leisure battery.
I thought the best way to tackle this would be to use 22mm plastic waste piping and fittings, installed in place of the random pieces of garden hose “laminated” in at the factory.

Phunkie Project Portafold (caravan!!)

So measured out and cut to length, it was trail fitted together.

Phunkie Project Portafold (caravan!!)

Before the body was turned onto its right hand side, the right side “conduit” was installed using strips of laminated about 150mm long.

Phunkie Project Portafold (caravan!!)

That’s about it for the moment, it’s back to repairing holes and corners for a while now.

[phunkie hiboy]

Right, back to the holes. All the side ones are now finished. Attention is now on the front centre storage hole. This actually has some quite bad damage (possibly where people have been using the front edge as a step to get onto the “sink unit bunk”).

Phunkie Project Portafold (caravan!!)

In view of the damage and the fact that we need to be able to store some larger camping items, that won’t fit through the 15” square holes, we’ve decided to open up the size of this front hole to 19” square.
First a square is cut out around the original hole, then a further 2” removed down both sides and 4” across the front of the remaining hole. Next the original “square” is cut into 4 in the centre of the sides, making 4 corners.
These corners are then fitted into the corners in the main body and then secured.

 

Phunkie Project Portafold (caravan!!)

The underside  of the join is then laminated and strengthened by adding electrical conduit to the layup.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

The join is then sanded back and laminated as in previous repairs.

Phunkie Project Portafold (caravan!!)

It is then shaped, sanded, filled and final sanded before hand priming.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

That now finishes all the storage hole repairs. Whilst looking around I did find quite a bad crack in the left hand rear up right post. I’m not sure how “bad” this is but have ground away and laminated it just as a precaution.

Phunkie Project Portafold (caravan!!)

So now back to the electrics………………………..
As I said, we’re going to use a hookup when we can, this will be also connected to a leisure battery via a charger (so the battery can be charged when we’re hooked up!).
I’ve managed to source a really slim hookup plug with flap from eBay. It’s going to be installed in the front, above the join seam and it will be hidden by the spare wheel (this will be mounted on a bracket from the front of the chassis.
The hole is marked out and a drill hole is drilled in each corner.

Phunkie Project Portafold (caravan!!)

The rest is then cut out with a saw. The round corners help alleviate cracks radiating from the corners of the hole. Securing holes are drilled and the socket trial fitted.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

We need some 13amp sockets inside some where, so it was decided there would be one at the front somewhere (to be decided) and one at the rear just inside the door.
The same method is used on this install as carried out on the hookup.

 

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

We’ve found some real slim sockets to use, including a lighting switch (all the lights will be 12v) to be installed on the opposite  side of the footwell.
Before I installed the lefthand side electrical conduit, I laminated the areas connecting both sides at the rear (under the step). I could see, maybe small items rolling under here and not being able to retrieve them. At this point I also laminated a piece of conduit tube through, from one side to the other, just in case we need to run some wires across.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

The excess conduit will be cut down as required.
The conduit for the electrics on the lefthand side is now laminated in, same as the righthand side previously.
The 16amp hookup wire is installed down the right side tube, into the socket box. The 7 core cable, for the rear lights is now prepared, split into 2 circuits left and right).

Phunkie Project Portafold (caravan!!)

There are some circuits that need to go down both sides, so wires with the correct corresponding colours are soldered in and sealed with heat shrink.

Phunkie Project Portafold (caravan!!)

The 2 lots of wires are now loomed up and installed in to their respective conduits.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

Well, that’s it for a while again, but at least the storage holes are finished now!!
If any one needs information on any of the items or suppliers of parts used on this project please drop me a line (PM or eMail).

[phunkie hiboy]

On with some more electrics then. More wires have been added for interior lighting (This will consist of small spotlights that run 12volt halogen bulbs, to be purchased from B&Q) and a couple of 12volt auxiliary sockets.
All the wiring that is required, from front to back is now installed into the conduit. The ends of the individual wires are cut to length and nipples soldered on.

Phunkie Project Portafold (caravan!!)

Expanded nylon sheathing is fitted and held in position with shrink tubing.

Phunkie Project Portafold (caravan!!)

Whilst on electrics, we want to be able to use a TV, and need to have some sort of aerial. I didn’t want to put anymore holes in the front area so have incorporated an aerial socket into the hookup box.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

Storage of items has been thought about since the start of the project and a couple of items require reasonably secure mountings, the battery and two Camping Gaz bottles.
A couple of small “steps” were fabricated from marine ply and test fitted. The ally angle was used to get both steps to be equally fitted both sides.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

These were laminated in place at the front curved area inside. Prior to fitting the left hand one, the “rack” for the gas bottles was constructed. A couple of strips of thin steel were shaped.

Phunkie Project Portafold (caravan!!)

A closing strip, with a over centre clip, added and test fitted to the “step” top.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

As I say this was done before installing the steps, and now laminated in a 2nd test fit for the bottles and a size test for the “battery”. I won’t be buying a battery until nearer the time to use (over 6 months away) so I made one from cardboard to the correct size to make sure it fits!!

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

An in between job that needed to be done was to plug the original hinge screw holes for the front and rear sections. This has been done because some of the original holes were drilled crooked and had produced cracked and spiders in the fibreglass inside, that will require repairing. It was just a matter of making some wooded dowels and hammer them home down the original holes. The holes have now been drilled straight.

Phunkie Project Portafold (caravan!!)

Back to the storage area, it was decided that it would have to be painted in something to cover up the rusty waterline and other parts.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

Having run out of materials, whilst doing the front mountings for battery and bottles, I came across a supplier in the west country who was cheaper with better quality on the resins I required. Looking through their web site I found they did a product called “Top Coat”. This product is like gel coat in looks, but unlike gel coat it has wax added to it so that it hardens off in air. Using gel coat for this leaves a sticky residue.
So we ordered the resins need plus grey top coat.
At this point, I have to say that bare laminated fibre glass is a nasty piece of work. If you are unlucky enough to rub it and suffer with a splinter, it hurts like **** and because it is practically see through, you can’t find it, so difficult to remove. Ask me how I know, got quite a few “T” shirts now. So another reason to use this stuff. Prior to using the fibreglass needs to be sanded, to remove any stray pieces of chopped strand.
It arrived, but what I thought was a nice light grey, it turned out to be dark battleship grey. Anyway, I had to go with it, but after painting both sides and the top inside it became evident that it as going to be too dark.
So onto plan “B”, order white top coat, we’ll need this for the interior sides and back, mix white in with the dark grey that’s left and hey presto, a much nicer colour.
So now the whole of the inside of the storage compartment is now coated with a smooth washable surface. I left the underside of the seating in the dark grey, as it was a pain to do and it doesn’t show, unless you stick your head right through the storage holes!!

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

More to come soon…………………………

[phunkie hiboy]

So I’m into the boring part now, filling and sanding. This will be by no means a show quality job, a huge amount of hours would be required for that. Just filling all the nicks and pock marked gel coat to a reasonable standard will take long enough.
Inbetween filling and sanding I’ve managed to get some other things done. Firstly the storage hole lids were in a pretty sad condition, with some delaminating and some broken in the same area as the damaged fibreglass edges. Using the old ones as patterns, new ones were cut and shaped to fit.

Phunkie Project Portafold (caravan!!)

This included one for the now larger front middle storage.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

They just require varnishing now.

Phunkie Project Portafold (caravan!!)

As we are only going to use this to sleep and sit in, ie no cooking and washing up etc, I’ve made a largish table that covers the front area in the middle.
Here are the materials ready to assemble.

Phunkie Project Portafold (caravan!!)

And now glued together in its intended position.

Phunkie Project Portafold (caravan!!)

Now there’s a little trick to this, because I’ve cut an shaped some boards to span from side to side, making a bed.

Phunkie Project Portafold (caravan!!)

 When not being used they are stored underneath the table.

Phunkie Project Portafold (caravan!!)

A tempered glass top will be made for the table, but we’ve not decided yet what will be under the glass.
Here we have all the panels out.

Phunkie Project Portafold (caravan!!)

And varnished.

Phunkie Project Portafold (caravan!!)

One more thing I’ve managed to do is the corner seal guides. They were all in pretty bad condition, mainly broken.

Phunkie Project Portafold (caravan!!)

So we had no alternative but to make some new ones. After some quick measurements, a mould was constructed to make new ones to the old specifications.

Phunkie Project Portafold (caravan!!)

So with the old ones and the adhesive removed.

Phunkie Project Portafold (caravan!!)

The new ones, shaped to fit were installed using white sikaflex. This is a sealer/adhesive which is paintable.

Phunkie Project Portafold (caravan!!)

They were then cleaned up and sanded to shape, ready for primer.
We can now supply, to order, new mouldings to do this job. They can come as just “U” section that requires shaping or roughly shaped pieces requiring finishing. Please note that all four corner pieces are different ( sizes and shapes) so they will require final finishing on the body.
That’s all for now.

[phunkie hiboy]

Well, we are still here and moving forward with this rebuild. Managed to get some more done before Christmas and after, although during the Christmas/new year recess I was working on another restoration project, on this little baby ………………….

Phunkie Project Portafold (caravan!!)

Anyway onwards and upwards.
So, we’ve replaced our cardboard battery with a state of the art carbon fibre 100amp leisure battery. A securing needed to be fabricated for it, together with a mount for the 240volt breaker and the solid state charger connected into the hook up circuit and the stand alone 12v circuit.
Firstly the battery and breaker.

Phunkie Project Portafold (caravan!!)

Then the charger.

Phunkie Project Portafold (caravan!!)

And finally all in position.

Phunkie Project Portafold (caravan!!)

Just got to hook up all the wiring now!!
Managed to get a final coat of boat varnish on the table frame edges, just need to get the glass cut and tempered now.

Phunkie Project Portafold (caravan!!)

I think that the quote “no wood to rot and no metal to rust” describing the construction of these ‘vans is a little bit of an under statement. Our ‘van suffers from both, rot in the wood and rust in the metal strengthening plates.
Starting with the rear wall, the plates to strengthen the hinge mounts were rusted and had split the fibreglass laminates.

Phunkie Project Portafold (caravan!!)

This lead to a large distortion of the fibreglass along those lower edges. Another connected reason for the distortion could also be the seized hinges.
The laminates were clamped together using “G” clamps and a long straight piece of wood running under both sides of the hinge mounting panels.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

I’ll explain the drill holes later. A piece of plywood was cut to match the profile of the mount.

Phunkie Project Portafold (caravan!!)

After a layer of resin and cut strand mat was added.

Phunkie Project Portafold (caravan!!)

The ply was added and laminated in.

Phunkie Project Portafold (caravan!!)

Phunkie Project Portafold (caravan!!)

These parts were then sanded and filled and resanded.

Phunkie Project Portafold (caravan!!)

Now the reason for the holes, we need to put in a lighting system. This will be 12volts and we need to get those 12volts from the main body (where they end now) to the walls (where the wires will terminate in some 12volt halogen 2” house lights).
The easiest way to do this, without having loose wires with plug in connectors draped all over, is to use some of these little devices.

Phunkie Project Portafold (caravan!!)

These particular ones can be found on the tailgates of Fait Chinquichento’s, other makes are available.
They are spring loaded contacts and this will give you some idea of how they work.

Phunkie Project Portafold (caravan!!)

The brass plate side will be fixed to the main body, whilst the spring loaded pins will be fixed to the end bases. When the ends are raised into position, the contacts will make the circuit to the lights.
Holes were made, to take the plates, in three places, two at the rear and one at the front.

Phunkie Project Portafold (caravan!!)

And the plates inserted into them.

Phunkie Project Portafold (caravan!!)

The holes for the spring loaded portion are cut into the added ply strengthening in the ends.

Phunkie Project Portafold (caravan!!)

It was decided to just glass in the wires up the end pieces, so they were masking taped to the inner wall.

Phunkie Project Portafold (caravan!!)

And then glassed in.

Phunkie Project Portafold (caravan!!)

At this point we needed to get rid of the flaking inner surface. We did this using rotary wire brushes on a cordless drill.

Phunkie Project Portafold (caravan!!)

Then finally to coat the inside with some “Topcoat” fibreglass resin, this time in white.

Phunkie Project Portafold (caravan!!)

So next time we’ll be starting on the front wall ………………………….

[Manky Monkey]

Like Dobber's catering units, this is something I've never thought about before.
An amazing amount of work going on there Chris. As you say, Portafolds are popular with the hotrod crowd so we see them all the time at the big weekend shows, but I've never really looked at one in detail. Intriguing.