Mk1 Escort Rebuild – Retropower Gordon Murray Episode 11


In this episode we get a look at the painted shell and the Retropower guys visit Nitron factory to see how the custom struts are progressing.  Some serious work has gone into the paint process, from a 2 pack acrylic base they progressively knocked back the finish with 1500 grit wet & dry, through to 3000 grit & mop cut and polish down to 3000 grit paste.  Rumour has it it will be followed up with a ceramic coating in a later episode.


Here’s Episode 11:








Transcript :

now it’s got paint on it feels like
another step forward now we’ve just got
to do they’re not scratching the paint
without further ado the painted shell
last time gums was literally walking
into the booth to spray the final coat
of paint which takes not very long
you know you literally talk in you know
two or three hours to completely do the
final exterior paint work on the car
after hundreds of hours of prep work and
we’ve sprayed it with just just a two
pack acrylic solid color it’s for Lerman
white which is the original twin cam
white color we’ve kind of gone for the
the two pack solid color rather than a
basing clear but you know you can get
two packs so it like so so kind of glass
flat but it still doesn’t have that kind
of miles deep brand-new car look about
it which we kind of wanted to avoid you
wants to paint it hardened off or best
part of a week we do the wet sanding and
polishing on it which is what takes it
from a gun finish where there’s a level
of orange peel there talked about this
last time to being completely flat and
nuts start with stiff blocks with 1500
grit some did wet
gradually go down finer so I’ll usually
then move to a 2,000 grit then we’ll use
3000 grit disks on a DA still wet if the
initial kind of hard blocking is just to
just to clip down that orange peel and
literally trim the tops off they’ll use
a book nerd art guide coat on a light
color like this until you can’t see any
guide coat left and then the progressive
final grades are basically to get the
something marks out from that initial
1500 grit and once you’ve got down to
3,000 in this case then we can go in
with the compound which is just a
basically an abrasive paste on a what
they call a mop on an electric machine
we’ve used system from fir Acula called
it’s actually a new one that just
recently brought out called the g 360
super fast system we’ve actually brought
out to speed up the initial cutting
process so you can do it from 1500 grit
but in our case we still wanted to take
it to 3,000 just to be absolutely sure
that something marks
no show at all initial cut with that
superfast correctly and then we move
down to the final grades of curricular
sort of finishing with like a real
ultrafine finishing compound and that’s
kind of the state you see in here
all the inside paint work was done first
we painted with the panels off so that
the doors for instance of painted
there’s a complete unit inside an out as
long in one go same with the bite and
the boot lid they were painted inside
and out in one go and then everything
assembled together afterwards which just
means there’s no kind of hidden areas
where you can’t quite get a nice paint
finish engine bay was painted at the
same time as the whole of the exterior
of the car which is pretty high pressure
on the go I do in the paint because he’s
got a clamber in underneath with it
exactly how it is now and sort of
squatting what is you know a really tiny
engine bay and get paint work everywhere
you know under all these hidden bits
under the edges of here whilst squatting
down in here and not then getting his
own overalls printed into the bank is
just painting which is obviously wet so
you know this is like the painters
Worth’s nightmare doing in an engine bay
like this you know a lot of people just
lean over and spray em but you just
can’t get the angle on some of the bits
that you want to get up under here and I
Fund it here and there’s so many bits
you can’t get to and you can’t see
clearly unless you’re right in there so
yeah he was literally in the engine bay
doing all the engine bay paint work
which as you can see has turned out
pretty nice happy with that very happy
with that
the reason the Dynomax in there now and
dying about being a sort of sound
deadening and heat insulating product to
try and get refinement in i don’t know
we’re gonna get criticized for adding
weight back into the car but it was
always stipulated as being a regular
used car with some degree of refinement
so we’ve got a lot of dynamite in there
to try and keep the drumming and the
noise down on the road noise down and
keep a bit of heat insulation in there
as well now the reason it’s in there now
is because before we did the wet sanding
on the car we wanted to make sure we wax
injected all of the kind of cavities
inside so that if any of the water from
wet something got down in there it
didn’t cause any corrosion so and then
it’s if once you’ve done that you get
wax oil over everything it’s very
difficult to stick the Dynomax on when
we’ve got the gunner finish from the
paint we Dynamat it first
then we weren’t to inject everything
then we must get and do the wet
something in that order so that we’ve
protected it so the work the water
doesn’t go anywhere and cause any
corrosion that we don’t want but we’ve
also got the dynamite on before the wax
so it actually sticks properly yeah
we’ve done the behind the grill work and
actually we did the dash at the same
time and it’s just it looks nicer it’s
to be honest it’s an opinion thing
actually they were originally black now
in there and it’s so when you’ve got the
grill on there and you look through the
grill you don’t see the painted bits
behind you just see in dark darkness
through the grill I actually on some
cars we’ve done I’ve actually not done
that because I quite like the look at
the body through the grill on it it kind
of has a bit of a motor sporty look to
it to me on this one I don’t think that
looks suited the car it’s nice to have a
bit of contrast as well on a white car
you want to see some dark there so we’ve
done that more or less than the original
forward positions although the grille
sits right forward here and then the –
we’ve also done satin black because
there is areas all around the top and
the lower part of the dash which that
will be its final finish it’s got a
loaded part on the top but all of the
sort of peripheral part of it that satin
black paint is the final visible finish
on it and also there is going to be a
bit of black on the back there’s a
section kind of where there’s a suede
line that comes up each side at an angle
and runs across over the slots that
we’ve put in the rear panel which we are
going to be doing black but I wanted to
make sure we could stand well back from
the car when we were sort of marking out
and visualizing how that was going to
look because I don’t want to mask it in
the paint booth paint it in here and
then go now look how that looks so we
need to kind of visualize it we’ll
probably just do it in black tape to
start with and then look at it from
different angles and probably get
Gordon’s opinion on where that’s going
to be because that’s quite an important
change to the look of the back of the
car to try and narrow it sort of height
wise make the car look wider and
narrower so we need to roll up and try
that and took before we do that
eventually when we’ve finished the build
up on it we will do a final
mopping with a really ultra fine
compound and it will be ceramic coated
but chances are were scratching it
between now and it being done are always
there so we don’t want to count our
chickens and all that now and then have
to redo it if something if we scratch it
or damage it in the meantime which I’m
hoping we won’t but
it’s best not to take the risk so yes
gonna leave here we’re gonna wheel it
through into the assembly shop and we
get to start doing the what I think is
the fun bit of starting to bolt finished
engineering parts onto a shiny shell and
I’m not no knots actually over at nitron
today seeing how they’re getting on with
the suspension builds so we’re gonna
have a little look at that
hi Maya and you did not make hi good to
see you
you wanna come right yeah
this this is kind of where we do most of
the bike stuff so it’s got the bike
specific parts you know laid out here
then we’ve got things that are motorbike
mojo motorbike forks all the cartridge
internal parts and then there’s a small
machine shop in there which is the in in
shock room machine shop so we have to
keep that clean but it does allow us to
modify parts a small lathe cleaning tank
a vacuum tank
these are shocks that come back in for
rebuild so they get stored there because
they’re dirty would have to clean them
take them apart so we basically make
sure the dirt stays in this in this part
here so this is just our little broom
we’ll put a door in here eventually so
this is this is the size of nitrile mark
one yes isn’t it this is the first the
first shed was about this big what what
year was that well it would have been
1998 yeah April 1998 was when I actually
officially started the company so yeah
it’s been 20 years
so with one one I’m gonna say unique
thing about about what we make is that
we test everything yeah so the design of
our product means that once we’ve
assembled it before we put out the door
we have to calibrate it and it’s a it’s
a purposeful point of the design because
I want to know that the product is
matched yeah does meet the the graft
criteria rather than sizing how much
some aren’t you put it together and it
is what it is it can’t change you can’t
adjust it you can’t tweak it therefore
you’re stuck hoping that the performance
is correct
so this is a McPherson strut being
dynoed and we’re doing the compression
cycle and we run it through a series of
speed checks and we checked that the
valving will give us a good damping
result on the speed up and the speed
down inside the stroke so it’s very
important that you get both sides of the
stroke to be a reasonable mirror image
it’s possible to have it so that as it
speeds up it produces one damping result
yeah and as it slows down going through
the sustainer set of speeds you get a
different damping result and this is
known as hysteresis when looking very
there is an allowance of hysteresis
nobody’s ever proved that hysteresis has
a particularly negative effect on a car
but from a pure shock point of view it’s
always nice to get a shot that has a
balanced upstroke and down stroke so
that’s what Mark is doing now he’s
dialing it in and he’s changing the
valving settings now and he’ll be set in
the calibration points to meet the
criteria he’s looking for
sorry I’m being nosy
so we run a heat probe on the shock so
make sure it’s up to temperature as well
you got to make sure the tests are done
under the same criteria all these shocks
and they all do the same thing so these
two are struts and these two are shocks
and the difference is this is this is
the the product of your engineering is
that this shock is always structure so
this shock actually holds the wheel up
mm-hmm and you got four of these one on
each corner on your car yeah and they
are different front to back of them
correct yeah yeah so you’ve effectively
designed and specified what you want
really we’ve not done that work so
you’ve given us the requirement and we
have made this different one and we’ve
made this so this will bolt on to the
the aluminium up right on the jungle
perhaps steel its aluminium on the front
elements the iron on the back I mean
education and this bracket here which is
steel fabricator steel bolts onto the
upright part and then you have the tube
that is the shock absorber part and it’s
got a really thick rod here this is a
very strong high carbon steel rod and
that resists the bending where the wheel
stops are collapsing into the wheel arch
and then you’ve got your bearings on the
top which is the the top plate which has
rubber inside it as well to isolate some
of the noise and smaller vibrations that
you get through from from the strut
itself and the adjustments on this
particular strut we have rebound on the
top here which we can turn and then on
the reservoir we have two compression or
bump modes a very low speed mode and a
high speed mode and we can think about
these two modes as the low speed is
driver input and the high speed is
something that has
happened to the car that the driver
didn’t didn’t cause so you might think
perhaps driving over a curb the driver
didn’t actually do that to the chassis
the wheels you want them to move very
fast inside the car so if you take a
kerb at a racetrack the wheel needs to
move very quickly you don’t want the car
to be upset that’s a high speed movement
whereas putting on the power the car
will change attitude going through a
turn the car will change its attitude
there’s a lower speed movement and
they’re controlled with the low speed
knob so that’s the way we kind of think
about the high speed under low speed
this truck does the same thing that
looks entirely different so this is a
BMW m4 that the newer type of BMW but it
does exactly the same things it bolts to
the car through this large diameter here
it has the compression same compression
adjustments and same mechanism and has
the same type of rod the same structural
steel tube and it has a top plate here
which is very adjustable so we can
adjust the camber and the caster on the
top of the car using these adjusters so
we can sit the way the wheel sits in the
car when you turn the steering the
caster will affect the cab build up that
you get and the the performance so does
the same thing but just looks totally
very old ford item is there so you’ll
recognize those the ad Cortina yeah but
we’ve actually machined these out of
solid so that’s our own solid machined
part that’s interesting to know if
they’re racing Cortinas we build them
slightly differently which is why this
one has come back for a modification so
you can see here there’s a cylinder of
gas the gas that is put into the shocks
is nitrogen yeah
and the reason why we do that this is
heavy and I’m going to put it down the
reason why we put know the reason why I
put nitrogen into the shocks is that
once we’ve done all the bleeding process
and we vacuum the product out and we put
the oil in if we then give it’s a 10 bar
of pressure 10 atmospheres of pressure
any miniscule air bubbles that are left
in there will be crushed to a tenth of
its size also during operation if you
imagine the oil wants to froth up the
action of the pressure of the gas stops
any frothing going on so the oil can
really be thrashed to bits inside with
the piston and shims and it won’t aerate
or create any any gas bubbles inside the
shock so we use nitrogen as an inert gas
to do that
so the name Nitron has come directly
from nitrogen gas
hi-yah further further work that we’ve
been up to mechanically I’ve done a few
bits one of them was rear brakes we are
constrained by a 13-inch wheel because
we want to make the car look similar and
look sort of correct to the period the
idea was Gordon was keen to have it
looking more or less like a lotus
twin-cam escort so we want to use the 13
inch steel wheel and we need to use a
hand brake caliper we want disks on the
back we need a hand brake on the back I
really want to use one caliper to do the
job the best option we kind of concluded
was this which is the Ford the trusty
old Ford Sierra unit that everybody uses
and that you can buy new again that’s
been remade because everybody uses them
it quickly became obvious having done a
couple of little sketches that it wasn’t
going to fit inside a wheel with any
sort of off-the-shelf disc that we
initially looked into so we I started
having a look at ways we could modify it
into the wheel color and color look at
it as well for a fresh pair of eyes and
we did use that if we move the caliper
in we’ve got a chance if we used a
smaller disc so we’ve got a smaller disc
with a slightly shorter top hat which
moved the disc outboard a little bit
which gave us a better chance of the
various bits of caliper clearing the
various bits of up right at that
diameter we to move the caliper in we
needed a machine various things we’re
trying to keep the service part standard
and the service parts will be wheel
bearing brake the brake caliper claw the
disc the pads and the CV joints
yes yeah yeah we’re getting its now
we’ve now it’s got paint on it feels
like another step forward now we’ve just
got to do they’re not scratching the
paint bit yeah yeah no I’m looking
forward to seeing it really with all the
parts coming together it’s gonna happen
a little bit more rapidly than some of
our builds in that we obviously not
completely dry built but but almost
completely dry built the car and a lot
of the parts are just new
oh that’s coming from there that’s
coming from there there’s a lot of just
a collection of new parts that there’s
going to be brought in quite a lot of
which were already finalized so it
should be we should be able to make
pretty rapid progress on some of it it’s
not to say it’s going to be finished in
five minutes but we’ll be able to get it
coming together quite quickly and yeah I
think that’s that’s the stage I like to
see once once plumbing starts going in
around an engine and the engines in
there and it’s on all its wheels and it
suspensions all operating it suddenly
feels like you’re building a car not
just a collection of bits that are
supposed to bolt together so yeah now
I’m looking forward to that it’s
definitely definitely another milestone
yeah I think the bit I’m looking forward
to the most is it Gordon riffing off of
the road in it it’s a vehicle it’s doing
the traditional it see if he comes back
with a smile on his face nasty that’s it
that’s that that’s the bit that I’ll be
most excited about
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