Silver Dawn; The Restoration Process

Silver Dawn
The Restoration Process
Classic Restoration and Services Ltd

The History
The Rolls-Royce Silver Dawn is a car that was produced by Rolls-Royce at their Crewe works between 1949 and 1955. This particular car was a J series
and one of the last to be built in 1955. Chassis no SVJ 39, production stopped at SVJ133. It was the first Rolls-Royce car to be offered with a factory
built body. The car was first introduced as an export only model. The left hand drive models had a column gear change, while right hand drives had a
floor change by the door. Only with the R Type based model was it officially available on the home market, from October 1953.
A mere 760 were produced between 1949 and 1955. Earlier models up to circa May 1954 had a different fascia (dashboard) from the Bentley Mk.VI
and 'R' Type, and were fitted with a single exhaust system. Later models from the SRH chassis series had the Bentley style fascia and the twin exhaust
system, as fitted to the Bentley 'R' Type.
The in-line six cylinder engine had overhead inlet and side exhaust valves and had a capacity of 4,257 cc until 1951 when it was enlarged to 4,566 cc.
The carburettor was a single downdraught Stromberg until 1952 when it was replaced by a Zenith. We converted this particular car to run on twin SU
carburettors as it results in better performance and fuel economy.
A four speed manual gearbox was fitted to all cars at first, with a 4-speed automatic becoming an option in late 1952 on the 'E' Series chassis, and on
the corresponding Bentley 'R' Type chassis.
The suspension was independent at the front using coil springs while at the rear the live axle used half elliptic leaf springs. The car had a separate
chassis made with traditional riveted construction until 1953 after which it was welded. Servo assisted 12.25 in (311 mm) drum brakes were used,
hydraulically operated at the front but retaining mechanical operation at the rear. Although many cars were fitted with factory built bodies, others were
supplied to external coachbuilders.

The Challenge Is To
Transform this Into this.

Inspection And Report We carry out a detailed inspection and
discuss options in great detail before
embarking on the restoration process. Every
customer has different goals and for some it
can simply be reliable and safe to use. For
others it is the pursuit of excellence with no
compromise to cost. This was certainly one
of those cases.
Dismantle and assess

Undressing
Remove doors, bonnet, boot and all
closing panels. Wings and wiring loom
removed followed by body mounts.
The Standard steel body is quite rigid
and requires no internal bracing
before removing the body, unlike
coach built or convertible cars. 12
bolts later and the body is removed.
The hard work begins.

Keeping Track Of The Parts
Every item removed is photographed and
inspected. It then starts its journey. Some items
requiring repairing, re-bushing, re-made or
simply re-finished or electroplated. An inventory
is created and every part is accounted for. Each
part goes through several processes before
ending up as a sub assembly awaiting final fit.
Boxes are numbered in ascending order and
during re-assemble the aim is to get to box one,
the first components removed is usually the last
fitted.

Good Place To Start
Every nut, bolt, washer, brace and
bracket removed. Sections are cut out and
new ones made and welded invisibly into
place. All corrosion is removed and
chemically treated before being
submerged in an acid tank to remove any
remaining oxides that can potentially
become corrosion. The next stage is the
painting.

Time For Re-assembly
Two pack acid etch to prevent further corrosion
and provide a base for the next process. Much
better than the original process.
Industrial isocyanate two pack paint. Designed to
exceed marine standards. Needs to be treated with
respect during the application.

The Engine
All parts go through a special process involving ground up walnut shells being blasted at the surface, under high
pressure, before being ultrasonically cleaned.

Improvements
The crank is ground, hardened and balanced before being polished and
assembled with all new bearings. The block is re-bored and new, bigger
pistons fitted. Valves are changed for stellited to accommodate lead free
fuel. The original inlet manifold is replaced to allow the fitment of twin
carbs. This not only improves the running but delivers more power. The
engine is refinished in full gloss epoxy paint and the original dull nickel is
re-plated using the original Watt’s process.

Carburettors
Just dealing with the Carburettors requires
re-plating more than seventy components,
painting a further forty and completely re-
designing the original throttle linkage. As
well as changing the Jetting to deliver the
best possible performance.

In The Mean Time
Corrosion is removed by cutting out
sections, making new pieces and welding
them into place. They are then filled to
provide an invisible repair before moving
on to the next and repeating this process.
The original bodies were made for Rolls
Royce by the London Press Steel Co. and
the tooling is no longer in existence. To
remake the more complex panels requires
a bit of creativity in making press tools
and bucks to reform the original panels.

Still More Corrosion
Only with the paint removed is the true extent of the
corrosion known.

Elsewhere In The Workshop
Between 70 and 150 components are painted each day in our paintshop while
other items are prepared and re-plated in readiness for final fit.

Chroming
This is used to protect the parent metal as well as improving the appearance. Firstly we remove the original
plating using chemicals or electrolyses depending on the parent metal. Repairs are carried out and the part is
then coppered. This seals the surface and protects it from further corrosion. This may be repeated several
times if further repairs are required. Copper is said to have good bridging properties and is able to fill in
minor imperfections. A close check is kept on the original dimensions as many of the components need to
fit together when finished. The copper is then polished to a mirror finish . Some of the copper is removed
electrically before the anodes are changed and the nickel applied. This ensures the surface is free of oxides
and a good molecular bond can take place. Nickel is harder than copper and provides a good surface for the
chrome to bond to. This is also polished to a mirror finish and inspected. Finally some of the nickel is
removed before the chrome is applied. One bolt done then onto the next. The original chrome is called
Hexavalent and possesses much better properties than the modern alternative Trivalent. However it does
produce toxic waste that needs to be stored indefinitely. It is for this reason the process is due to be banned
on September 21st 2017.

Watts Nickel
Watts nickel plating baths can deposit both bright and semi-bright nickel. Bright nickel is typically used for
decorative purposes and corrosion protection. Semi-bright, as favoured by Rolls Royce and Bentley deposits are
used where a high lustre is not required. The benefit of the process is it deposits nickel evenly over the surface with
low internal stresses. This means a component can be bent or manipulated without the nickel cracking or peeling
unlike modern nickel plating methods that tend to cause embrittlement. Copper is usually applied before this
process is carried out. The disadvantages are, because the process uses low current and takes much longer it ties up
the plating tanks for a long time and this adds to the cost. Most electroplaters use the more lucrative methods and
choose to dull the surface with steel wool or similar. This is not suitable and will result in the plating peeling off.

All Electrical Switches And Components Are
Overhauled

The Running Chassis
A bench seat is added and the chassis can be driven to test performance.

Repairs complete, the underside is painted and
coated in a Ruberoid to prevent stone chip damage.

Preparation
It is said that preparation is everything, this is very true. Before paint is applied to the
body the body is baked in the oven. 40 degree centigrade for about 40 minutes, until
the skin reaches the correct temperature. It is then washed using an acid to remove any
oxidation. Next stage is panel wipe, this is solvent based and removes finger prints and
any contaminants on the surface. A two pack acid etch is then sprayed on. It receives
three coats, most of which is absorbed into the metal and provides a key for the next
process. Baked at 60 degrees centigrade for about 40 minutes before being left for 24
hours. The surface is then prepared using a very fine abrasive. Three coats of two pack
epoxy primer is applied. After three coats, it is then baked and left for a minimum of
24 hours. It will be hand blocked and the process repeated several times to remove
even the smallest imperfections. The paint thickness is constantly checked to ensure
the product is kept to a minimum.

Now It Gets Exciting
All doors and closing panels
pre-fitted and gapped before
the body is painted inside and out.
Now is the time to choose the colour.

Painting
As before the body is baked to reach the desired panel temperature. In this case
24 degrees centigrade. Even the air going through the spray gun is chilled and
dried to remove moisture before being heated to the correct temperature. The
base coat is then applied leaving about 20 minutes between each coat. A total
of three coats are applied before being baked at 60 degrees centigrade for 40
minutes. This chemically hardens the paint and removes any chance of solvent
entrapment. It is left to rest for a minimum of 24 hours before the next
process.

Hard Choices
Because all the processes apart from electroplating are carried out in house we
are able to offer an unrestricted choice. We mix, tint and blend our paint to
provide any desired colour. We use the finest hides in a wide variety of colours,
with the option of having batches dyed to meet a customers exact needs and
the same is also true of carpets although we tend to favour Wilton. We can also
supply veneers from thousands of species and usually supply samples for the
customer to ponder before deciding. Sometimes the greater the choice the
harder it is to decide. This stage cannot be rushed.

Base Coat Is Applied
Masons Black

Next Stage
The base coat is again blocked back ready for the second colour. Because the
colour continues into the door shuts, the doors are fitted and the returns are
masked. The doors are then removed and the inside painted before being
refitted. With the doors refitted and areas not to be painted masked the second
colour is applied. Again three coats with a 20 minute gap between each coat to
allow the solvent to escape.

Royal Claret For The Second Colour
After weeks of hand blocking the effort is reflected in the finish.

The Marriage
The body is put back on the chassis and it starts to look like a car again.

The Fit Up
Doors and closing panels re-fitted and every gap measured.

Keeping It Cool
The original radiator core is
replaced by a slightly thicker and
more efficient film type core. Two
thermostatically controlled fans
are fitted in the space between the
core and the shell. Four
condensing radiators are fitted in
a space under the front wings.
These have a further two cooling
fans fitted and a cover made to
protect them from stones.

Time For Some Alterations
Doors have been previously altered to accept additional speakers.
Check straps are fitted to conceal the speaker
wires.
We also took the opportunity to install remote
central locking.

Air Conditioning
Probably the hardest modification to do well, as there are several things to consider. Firstly you have to provide
additional power, or the compressor can effect the vehicles performance. We carried out several modifications to
the engine to offset any additional load created by the compressor. The compressor itself must be powerful
enough to run the system. Most compressors supplied for our UK domestic market are completely unsuitable
for middle or far east countries. Calculations are carried out to establish the Kw rating of the compressor
needed. Better to use a large one with extra capacity than a small one that can only just cope. In hot countries
the sun radiates heat on the body panels and this in turn conducts the heat inside the car, this is referred to as
heat gain. Any system should incorporate a high level of thermal insulation. The method we use has very good
thermal and acoustic insulation properties but we will come to that later. Finally appearance and functionality. It
has to look like it belongs and it has to be usable without excessive noise and causing your knees to freeze while
your body is still hot. On this application we used a very powerful compressor with four condensers to loose the
heat and two evaporators to supply the cold air. The whole system was built in to the frame of the car and
concealed from view.

Hiding Components
This is planned at a very early stage and the assemblies are
made and pre fitted. They are then boxed and ready for
final fitment. The compressor and high power
alternator(165amp) are fitted at the running chassis stage
while the front evaporator is made and fitted while the
body is undergoing corrosion repairs. This occupies the
space that used to house the only speaker. The speaker is
replaced by fifteen speakers ranging from tweeters to
woofers. The original vent is remade to incorporate
movable louvers and when finally fitted appears almost
invisible.

Rear Air Conditioning
The rear vents provide a curtain of cold air
above the rear door with the ducting
concealed behind the head lining. The parcel
shelf incorporates a return vent that also
provides cooling for both audio amps. In the
picture you can also see the high level brake
light. The boot is repanelled to create a false
bulkhead to house the rear evaporator, audio
amps, additional speakers and seat belt
mounts. Most of the room is used by a sub
woofer that requires 1cubic foot of air
space. Seriously loud!

Optional Extras
Space is running out. We need to create room to house
some additional switches and controls. We dismantle
the arm rest and experiment with options. We then
make the frame of the new arm rest and house air
conditioning rear controls. The USB is connected to
the front head unit and allows music to be played using
a flash drive. It also incorporates a charging point and
not to forget the phone. It is then lined and covered in
leather to match the rest of the interior trim. Behind
the arm rest is the rear sub woofer so you can quite
literary feel the music.

The Audio System
Again carried out at an early stage. This section of dash is remade to mirror the nearside glove box. The head unit is
trial fitted. This will also house the front air conditioning controls and a further USB plug. It is then re-veneered and
lacquered to match all other interior joinery before being boxed for a later date.

Joinery
All woodwork is remade or repaired before being veneered using the same log. In this case the cluster burr
walnut and straight grain walnut cross banding came from a tree in the south of France. The veneers are
all hand picked based on depth of colour and figuring.

More Toys
In order to make the car more usable we installed some
features common in modern motor cars.
Programmable parking proximity sensors fitted in rear
reflector. Electric seats mounted inside the seat frame.
Reversing camera and high level brake light with
housings made to match existing joinery. Electric
power steering. Remote central locking. Bluetooth and
infrared sensors mounted in the headlining. An
integrated microphone is also mounted in the
headlining and of course the studio quality sound
system.

The Finished Car
Rolls Royce factory only a few miles from
our workshop makes the perfect backdrop
for our photoshoot. Notice the seats in the
background all empty. All the staff
couldn’t resist coming out and admiring
the finished car.

Pride Of Place

Before And After

A Bit Of An Improvement

Silver Dawn; The Restoration Process

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