\"Headlight\" polishing...

[Don Y]

On 2/21/2023 2:22 AM, Liz Tuddenham wrote:

Don Y <blockedofcourse@foo.invalid> wrote:

On 2/20/2023 2:30 PM, Liz Tuddenham wrote:
Carlos E. R. <robin_listas@es.invalid> wrote:

On 2023-02-20 21:31, Liz Tuddenham wrote:
Don Y <blockedofcourse@foo.invalid> wrote:

[...]
That suggests that any polishing operations likely further remove
the coating, thus accelerating a recurrence? (Or, do commercial
products targeting this application include a followup \"resealing\"
operation -- presumably, with a BETTER protectant than the original?)

I used a (quite expensive) commercial remover and re-coater about 2
years ago, it has completely failed already. Ordinary metal polish
seems to clean the surface clouding, and I am now looking for a cheap
clear varnish that will block UV and is easy to remove when necessary.
Unfortunately most outdoor varnishes seem to contain polyurethane which
is difficult to remove when it starts to break down and peel off.

I\'m curious.

Block UV from the lamp, or from the sun? And why?

As far as I can tell, the polycarbonate lens is affected by UV from the
sun (and the sky in general) and reacts by going milky. A coating is
applied to the outside to block external UV, but, as you point out,
there is also UV emitted by halogen bulbs that may affect the inside
(perhapes depending on the wavelength)..

I don\'t know whether the UV penetrates the thickness of the
polycarbonate and damages it right through, or whether it only affects
the surface which can be taken off with fine abrasive from time to time.

Or, is the protective coating the material that is clouding?

I think that is the first thing that happens, then the lens starts to go
cloudy too. The \'rejuvenator\' works mainly by stripping and replacing
the coating. It contains some unusual-smelling solvents which give the
impression of being quite toxic.

But, it (or the abrasive compounds mentioned) must also be doing
something to the \"affected lens\" else the cloudiness would persist
beneath the new coating (?) I wonder how many \"other\" defects
the process can remove from the part? (e.g., scratches, stains,
etc.)

Ideally (for me), there would be a liquid-ish solution^H^H^H
approach that could get into nooks and crannies to fix the
problem *and* act to minimize its recurrence.

Having to sand -- or buff -- means the shape becomes important to
the effectiveness of any \"cure\". You\'d have to define HOW the
part was going to be sanded/buffed *before* undertaking the design!

E.g., you can \"smooth out\" (some) 3D printed parts with an
acetone wash -- the solvent acting to knock down the
\"ribs\" that the printer inherently imparts to the piece.
So, post processing isn\'t as critical about the object\'s
shape. Or, the solvent\'s application.

Glass, OTOH, doesn\'t have that fogging problem and could just
be washed if soiled -- in solvents of varying degrees of
aggressiveness.

(sigh) I am gaining a new respect for the folks who have to
address the \"non-electronic\" aspects of product designs! No
doubt, they already have some background in the characteristics
(assets/liabilities, indications/contraindications) of various
materials...

 

[Don Y]

On 2/21/2023 2:46 AM, Liz Tuddenham wrote:

Wouldn\'t the sandpaper leave fine scratches in the material?

that\'s why you need multiple grits, you start with the coarsest to
thremove material and en each finer grit removes the scratches from the
thprevious grit. Sanding 101

I would still think that would leave scratches -- albeit very fine
ones. These wouldn\'t be present if a \"buffing wheel\" was used
(with a lubricating agent).

The kits contain a re-coating varnish which has a similar refrective
index to the lens material. This fills in any small residual scratches.

OK. So, it\'s not just to restore the UV protection.

you can get coatings that claim to prevent the problem, but I have no
idea if they really work > https://www.amazon.com/gp/product/B01M4RVVX6
Which begs the question, \"Why don\'t car manufacturers use it?\"

they do, the bottle says lasts for a a year...

After two years mine was so bad it got an \'advisory\' warning at the MOT

MOT = Department of Motor Vehicles?

Our vehicles aren\'t routinely inspected. When you initially register
a vehicle, a cursory \"safety check\" is made. Damn near any vehicle
that looks like a *complete* vehicle (i.e., no missing doors) will
likely pass.

Vehicles are, however, checked for compliance with emission standards,
annually. This is done by putting the car on a dyno and monitoring
exhaust under a specific load. As well as during the \"return to
idle\" phase (some vehicles will \"cough\" dirtily in that event).
And, verifying a good gas cap seal, no modifications made under
the hood or below the vehicle, presence of catalytic converter, etc.

[You, of course, pay for this -- including the postage required to
mail the notice of a pending test to your home!]

Some places impose \"city registration stickers\" on vehicles.
It is not uncommon for police to patrol parking lots on the first
of the month looking for expired stickers (the fine is comparable
to the cost of the sticker!)

test. If this is going to be an annual job, it will be a non-trivial
addition to the running expenses.

I\'m looking at the *material* for use in another application.
If it routinely got cloudy, then I would want a way of easily
cleaning it (which would affect its designed shape) *or*
replacing it.

For other similar items, I\'ve used glass as maintenance is
costly, in general. So, if I can eliminate it in a given
application, I try to do so.

On a previous car I found the beam pattern of the headlights was so bad
it dazzled oncoming drivers, and didn\'t illuminate the roadside verge.

Hmmm... another word for my vocabulary! :>

Oncoming drivers kept flashing their headlights at me, even though mine
were on dipped beam and adjusted according to the manufacturer\'s
instructions.

SWMBO\'s vehicle got a similar reaction, initially. I feared the
lights weren\'t aimed properly so checked them, myself. I came
to realize their height (off the road surface) and being LEDs
made them appear brighter/higher. Flashing *my* high beam
would quickly tell the on-comers that mine weren\'t previously
\"on high\"

I used to dread the slightest trace of fog because there
were shafts of light projecting upwards immediately in front of the
bonnet that lit up a dazzling curtain and blocked my view of the road.

In desperation I scrapped the fancy styled headlights and replaced them
with a black-painted rectangle of aluminium with a circular hole in the
middle. Then I fitted a pair of ordinary 7-inch round halogen
headlights with glass lenses. There were a few raised eyebrows from the
MOT tester, but the beam pattern was correct, so he issued a \'pass\'
certificate.

You couldn\'t, perhaps, have found a glass face off a similarly
sized/shaped lamp to mount in front of the original lamps?

Or, would that not provide any additional \"fog protection\"?
(some, here, have suggested exhaust emissions may be a contributing
factor so the glass would act as an insulator in that case).

The modification transformed night driving and, of course, there were no
ageing problems with the glass lenses.

Glass is a remarkable material! I keep coming back to it for
uses in my projects...

sadly, it\'s not trivial to \"manipulate\" -- beyond BREAKING it!

 

[Liz Tuddenham]

Don Y <blockedofcourse@foo.invalid> wrote:

I think that is the first thing that happens, then the lens starts to go
cloudy too. The \'rejuvenator\' works mainly by stripping and replacing
the coating. It contains some unusual-smelling solvents which give the
impression of being quite toxic.

But, it (or the abrasive compounds mentioned) must also be doing
something to the \"affected lens\" else the cloudiness would persist
beneath the new coating (?) I wonder how many \"other\" defects
the process can remove from the part? (e.g., scratches, stains,
etc.)

There appear to be two stages to the problem, the protective film starts
to break up, then the lens surface becomes cloudy. The film has to be
removed first, then the lens surface can be tackled if the damage has
gone that far.

Ideally (for me), there would be a liquid-ish solution^H^H^H
approach that could get into nooks and crannies to fix the
problem *and* act to minimize its recurrence.

Unfortunately there don\'t seem to be any plastic-based UV protective
varnishes that aren\'t eventually broken down by exposure to the UV.
Glass is the best option, but you won\'t paint it on with a brush!


--
~ Liz Tuddenham ~
(Remove the \".invalid\"s and add \".co.uk\" to reply)
www.poppyrecords.co.uk

 

[Liz Tuddenham]

Don Y <blockedofcourse@foo.invalid> wrote:

On 2/21/2023 2:46 AM, Liz Tuddenham wrote:
Wouldn\'t the sandpaper leave fine scratches in the material?

that\'s why you need multiple grits, you start with the coarsest to
thremove material and en each finer grit removes the scratches from the
thprevious grit. Sanding 101

I would still think that would leave scratches -- albeit very fine
ones. These wouldn\'t be present if a \"buffing wheel\" was used
(with a lubricating agent).

The kits contain a re-coating varnish which has a similar refrective
index to the lens material. This fills in any small residual scratches.

OK. So, it\'s not just to restore the UV protection.

I am tempted to say it is not *even* UV protection, based on my
experience.

[...]

After two years mine was so bad it got an \'advisory\' warning at the MOT

MOT = Department of Motor Vehicles?

Ministry of Transport Test: An annual test that is compulsory in the
UK. It started off sensibly with checks to see that the brakes worked
and the steering wasn\'t loose. Now it is an elaborate series of
bureaucratic hurdles that change every year and are so expensive to keep
updating that fewer and fewer garages are willing to undertake them.

[...]

If this is going to be an annual job, it will be a non-trivial
addition to the running expenses.

I\'m looking at the *material* for use in another application.
If it routinely got cloudy, then I would want a way of easily
cleaning it (which would affect its designed shape) *or*
replacing it.

If you find one, let us know. This seems to be one of life\'s great
usolved problems.

[...]

Oncoming drivers kept flashing their headlights at me, even though mine
were on dipped beam and adjusted according to the manufacturer\'s
instructions.

SWMBO\'s vehicle got a similar reaction, initially. I feared the
lights weren\'t aimed properly so checked them, myself. I came
to realize their height (off the road surface) and being LEDs
made them appear brighter/higher.

This waan\'t a brightness problem, they were fitted with normal bulbs.
The design of the reflector was completely wrong with shafts of light
firing off in all directions. The manufacturer had obviously
concentrated on the central beam pattern and ignored everything outside
a 30-degree cone. Some beams were nearly vertical, others were at 45
degrees across the road and about 10 degrees above horizontal.

I could see an obscuring plate inside the lens, but it appeared to have
been rivetted in place upside down, so it blocked the downward-reflected
beam and did not stop the upward-reflected beam. The unit could not be
fitted the wrong way up, so the fault must have occurred during headlamp
manufacture. All the cars of that model and year had the same problem.
They passed the MOT test because the beam testing machines only measured
the central part of the beam.

I used to dread the slightest trace of fog because there
were shafts of light projecting upwards immediately in front of the
bonnet that lit up a dazzling curtain and blocked my view of the road.

In desperation I scrapped the fancy styled headlights and replaced them
with a black-painted rectangle of aluminium with a circular hole in the
middle. Then I fitted a pair of ordinary 7-inch round halogen
headlights with glass lenses. There were a few raised eyebrows from the
MOT tester, but the beam pattern was correct, so he issued a \'pass\'
certificate.

You couldn\'t, perhaps, have found a glass face off a similarly
sized/shaped lamp to mount in front of the original lamps?

No, the fault was inside the reflector and in the shape of the reflector
itself. Complete replacement with a pair of Wipac Quadoptics was the
only solution (I see thay are still made - but some Chinese copies now
have plastic lenses!!!)


--
~ Liz Tuddenham ~
(Remove the \".invalid\"s and add \".co.uk\" to reply)
www.poppyrecords.co.uk

 

[Dean Hoffman]

On Monday, February 20, 2023 at 8:50:39 PM UTC-6, Lasse Langwadt Christensen wrote:

tirsdag den 21. februar 2023 kl. 03.26.19 UTC+1 skrev Dean Hoffman:
On Monday, February 20, 2023 at 12:33:53 PM UTC-6, Don Y wrote:
Does the \"fog\" that plagues modern headlights come as
a result of UV damage? Or, fine-particle abrasion
(the lights being on the leading edge of the vehicle)?

Given that forming large \"oddly shaped\" objects out of
glass is costly (or so my glass-guy tells me!), are
there other transparent materials that could be used?

[If so, why didn\'t car manufacturers use it/them?]

And, in the event of polycarbonate being the only
practical, \"moldable\" solution, how can I define
constraints on the shape to ensure it can be
\"reasonably\" polished when/if such damage occurs?
(assuming I\'m not keen on replacement)

[E.g., a purely convex surface would be easier to
polish than one that arbitrarily mixes concave and
convex; though, even there, too high a degree of
curvature could prove difficult to manage]

In the good old days, there were cars that had \"eyelids\" that closed when the headlights weren\'t in use.
that was to hide the ugly headlights the rules forced them to use in the US, the choice was round or square
sealed beam

Is there such a thing as a material that is normally dark but transparent when 12vdc is applied to it? Maybe Don could make some sort of headlight mask that does that and be famous forever.

 

[Carlos E. R.]

On 2023-02-21 10:22, Liz Tuddenham wrote:

Carlos E.R. <robin_listas@es.invalid> wrote:

[...]
I don\'t think halogen emits much UV. Rather IR.

They emit a lot of IR but they also emit a significant amount of UV.

I found the beam pattern of a halogen foglight at a distance of about
500mm was the same shape and size as a recumbent piglet, so I designed a
piglet incubator using 24v lorry foglights. After a while we found that
the piglets were getting sunburnt, so we had to fit UV filters to the
foglights.

These lamps were probably only emitting long-wavelength UV; damage to
plastics is more likely to be caused by short-wavelength UV found in
sunlight.

Interesting.

--
Cheers,
Carlos E.R.

 

[Carlos E. R.]

On 2023-02-21 10:46, Liz Tuddenham wrote:

Don Y <blockedofcourse@foo.invalid> wrote:
On 2/20/2023 7:43 PM, Lasse Langwadt Christensen wrote:
tirsdag den 21. februar 2023 kl. 03.09.27 UTC+1 skrev Don Y:

On a previous car I found the beam pattern of the headlights was so bad
it dazzled oncoming drivers, and didn\'t illuminate the roadside verge.
Oncoming drivers kept flashing their headlights at me, even though mine
were on dipped beam and adjusted according to the manufacturer\'s
instructions. I used to dread the slightest trace of fog because there
were shafts of light projecting upwards immediately in front of the
bonnet that lit up a dazzling curtain and blocked my view of the road.

In desperation I scrapped the fancy styled headlights and replaced them
with a black-painted rectangle of aluminium with a circular hole in the
middle. Then I fitted a pair of ordinary 7-inch round halogen
headlights with glass lenses. There were a few raised eyebrows from the
MOT tester, but the beam pattern was correct, so he issued a \'pass\'
certificate.

Any modification and here you do not pass. We have to replace with the
same model of fixture.

The modification transformed night driving and, of course, there were no
ageing problems with the glass lenses.

--
Cheers,
Carlos E.R.

 

[Carlos E. R.]

On 2023-02-21 12:53, Dean Hoffman wrote:

On Monday, February 20, 2023 at 8:50:39 PM UTC-6, Lasse Langwadt Christensen wrote:
tirsdag den 21. februar 2023 kl. 03.26.19 UTC+1 skrev Dean Hoffman:
On Monday, February 20, 2023 at 12:33:53 PM UTC-6, Don Y wrote:
Does the \"fog\" that plagues modern headlights come as
a result of UV damage? Or, fine-particle abrasion
(the lights being on the leading edge of the vehicle)?

Given that forming large \"oddly shaped\" objects out of
glass is costly (or so my glass-guy tells me!), are
there other transparent materials that could be used?

[If so, why didn\'t car manufacturers use it/them?]

And, in the event of polycarbonate being the only
practical, \"moldable\" solution, how can I define
constraints on the shape to ensure it can be
\"reasonably\" polished when/if such damage occurs?
(assuming I\'m not keen on replacement)

[E.g., a purely convex surface would be easier to
polish than one that arbitrarily mixes concave and
convex; though, even there, too high a degree of
curvature could prove difficult to manage]

In the good old days, there were cars that had \"eyelids\" that closed when the headlights weren\'t in use.
that was to hide the ugly headlights the rules forced them to use in the US, the choice was round or square
sealed beam

Is there such a thing as a material that is normally dark but transparent when 12vdc is applied to it? Maybe Don could make some sort of headlight mask that does that and be famous forever.

Yes, LCD

--
Cheers,
Carlos E.R.

 

[Dean Hoffman]

On Monday, February 20, 2023 at 8:50:39 PM UTC-6, Lasse Langwadt Christensen wrote:

tirsdag den 21. februar 2023 kl. 03.26.19 UTC+1 skrev Dean Hoffman:
On Monday, February 20, 2023 at 12:33:53 PM UTC-6, Don Y wrote:
Does the \"fog\" that plagues modern headlights come as
a result of UV damage? Or, fine-particle abrasion
(the lights being on the leading edge of the vehicle)?

Given that forming large \"oddly shaped\" objects out of
glass is costly (or so my glass-guy tells me!), are
there other transparent materials that could be used?

[If so, why didn\'t car manufacturers use it/them?]

And, in the event of polycarbonate being the only
practical, \"moldable\" solution, how can I define
constraints on the shape to ensure it can be
\"reasonably\" polished when/if such damage occurs?
(assuming I\'m not keen on replacement)

[E.g., a purely convex surface would be easier to
polish than one that arbitrarily mixes concave and
convex; though, even there, too high a degree of
curvature could prove difficult to manage]

In the good old days, there were cars that had \"eyelids\" that closed when the headlights weren\'t in use.
that was to hide the ugly headlights the rules forced them to use in the US, the choice was round or square
sealed beam

It sticks in my mind that there was a plastic film intended for south facing windows in the summer. It would filter sunlight but let light from something like a flashlight through.
Maybe I\'m just remembering the \"good old days\" which were better than today.

 

[Don Y]

On 2/21/2023 5:09 AM, Carlos E. R. wrote:

On 2023-02-21 10:46, Liz Tuddenham wrote:
Don Y <blockedofcourse@foo.invalid> wrote:
On 2/20/2023 7:43 PM, Lasse Langwadt Christensen wrote:
tirsdag den 21. februar 2023 kl. 03.09.27 UTC+1 skrev Don Y:


On a previous car I found the beam pattern of the headlights was so bad
it dazzled oncoming drivers, and didn\'t illuminate the roadside verge.
Oncoming drivers kept flashing their headlights at me, even though mine
were on dipped beam and adjusted according to the manufacturer\'s
instructions.  I used to dread the slightest trace of fog because there
were shafts of light projecting upwards immediately in front of the
bonnet that lit up a dazzling curtain and blocked my view of the road.

In desperation I scrapped the fancy styled headlights and replaced them
with a black-painted rectangle of aluminium with a circular hole in the
middle.  Then I fitted a pair of ordinary 7-inch round halogen
headlights with glass lenses.  There were a few raised eyebrows from the
MOT tester, but the beam pattern was correct, so he issued a \'pass\'
certificate.

Any modification and here you do not pass. We have to replace with the same
model of fixture.

Here, each state comes up with their own rules (after initial manufacture).

Some places are PITAs and seem to go out of their way to put extra steps
in your way to make it harder for you to comply. It\'s not that you *won\'t*
be able to comply but, rather, that you\'ll have to jump through a few
hoops along the way... that don\'t seem to serve any \"real purpose\"!

After initial registration, I don\'t think there is any ongoing requirement
for *proving* the road-worthiness/safety of a vehicle. New vehicles are
pre-blessed by the manufacturer\'s compliance.

I\'ve lived in places (states) where I needed to be fingerprinted to
get a driver\'s license; places where the license had to be renewed
every ~4-5 years (some with \"driving tests\" as part of the process);
some where my license didn\'t require renewal for *30+* years;
places where I had to promptly change my registration to reflect my
residence in the state; some where a change of address could be
accommodated by \"taping a slip of paper with your NEW address onto
your existing credential\"; some where my vision test included tests for
colorblindness; some where vehicle age made it inherently harder to keep
it on the road; other places where it was *easier*; places where
registration was a flat fee; places where registration was based on
the current value of the vehicle -- or the available horsepower; etc.

But, then again, the US is a geographically large area and the design
of our constitution intentionally tries to give rights to the individual
states, instead of imposing them from the federal level.

If you are born and raised in one particular area (state) and remain
there, you likely aren\'t even aware that things are different, elsewhere.

The modification transformed night driving and, of course, there were no
ageing problems with the glass lenses.

 

[Don Y]

On 2/21/2023 5:13 AM, Carlos E. R. wrote:

On 2023-02-21 12:53, Dean Hoffman wrote:
On Monday, February 20, 2023 at 8:50:39 PM UTC-6, Lasse Langwadt Christensen
wrote:
tirsdag den 21. februar 2023 kl. 03.26.19 UTC+1 skrev Dean Hoffman:
On Monday, February 20, 2023 at 12:33:53 PM UTC-6, Don Y wrote:
Does the \"fog\" that plagues modern headlights come as
a result of UV damage? Or, fine-particle abrasion
(the lights being on the leading edge of the vehicle)?

Given that forming large \"oddly shaped\" objects out of
glass is costly (or so my glass-guy tells me!), are
there other transparent materials that could be used?

[If so, why didn\'t car manufacturers use it/them?]

And, in the event of polycarbonate being the only
practical, \"moldable\" solution, how can I define
constraints on the shape to ensure it can be
\"reasonably\" polished when/if such damage occurs?
(assuming I\'m not keen on replacement)

[E.g., a purely convex surface would be easier to
polish than one that arbitrarily mixes concave and
convex; though, even there, too high a degree of
curvature could prove difficult to manage]

In the good old days, there were cars that had \"eyelids\" that closed when
the headlights weren\'t in use.
that was to hide the ugly headlights the rules forced them to use in the US,
the choice was round or square
sealed beam

          Is there such a thing as a material that is normally dark but
transparent when 12vdc is applied to it?   Maybe Don could make some sort of
headlight mask that does that and be famous forever.

Yes, LCD

You can buy (house) windows with this capability.

 

[Don Y]

On 2/21/2023 4:28 AM, Liz Tuddenham wrote:

Ideally (for me), there would be a liquid-ish solution^H^H^H
approach that could get into nooks and crannies to fix the
problem *and* act to minimize its recurrence.

Unfortunately there don\'t seem to be any plastic-based UV protective
varnishes that aren\'t eventually broken down by exposure to the UV.
Glass is the best option, but you won\'t paint it on with a brush!

Yes, the cost of (large) custom glass pieces is a real
nuisance. If it\'s not easy to maintain something made
out of a \"plastic\", then the solution will be to alter
the design to make it easy to replace them (cost of
replacements is pennies). And, some mechanism of
detecting when replacement is required.

Then, hope the end user heeds the maintenance-minder
(and doesn\'t just complain because \"it\'s broke\"!)

I\'m still not convinced that there isn\'t another material
(other than glass) that would be more tolerant of UV
exposure. After all, there are a lot of things that
are deployed out-of-doors that don\'t have \"XXXXX polishing
kits\" available for their maintenance!

 

[Lasse Langwadt Christensen]

tirsdag den 21. februar 2023 kl. 22.03.14 UTC+1 skrev Don Y:

On 2/21/2023 4:28 AM, Liz Tuddenham wrote:
Ideally (for me), there would be a liquid-ish solution^H^H^H
approach that could get into nooks and crannies to fix the
problem *and* act to minimize its recurrence.

Unfortunately there don\'t seem to be any plastic-based UV protective
varnishes that aren\'t eventually broken down by exposure to the UV.
Glass is the best option, but you won\'t paint it on with a brush!
Yes, the cost of (large) custom glass pieces is a real
nuisance. If it\'s not easy to maintain something made
out of a \"plastic\", then the solution will be to alter
the design to make it easy to replace them (cost of
replacements is pennies). And, some mechanism of
detecting when replacement is required.

Then, hope the end user heeds the maintenance-minder
(and doesn\'t just complain because \"it\'s broke\"!)

I\'m still not convinced that there isn\'t another material
(other than glass) that would be more tolerant of UV
exposure. After all, there are a lot of things that
are deployed out-of-doors that don\'t have \"XXXXX polishing
kits\" available for their maintenance!

most of them don\'t get hammered with high speed sand and dirt regularly
like headlights do

But it definitely happen other things too. At work we have some curved skylights
that are plastic probably PC. Some of them, the old ones, are still clear. Those
that have been replaced later are all yellow

 

[Don Y]

On 2/21/2023 4:28 AM, Liz Tuddenham wrote:

MOT = Department of Motor Vehicles?

Ministry of Transport Test: An annual test that is compulsory in the
UK. It started off sensibly with checks to see that the brakes worked
and the steering wasn\'t loose. Now it is an elaborate series of
bureaucratic hurdles that change every year and are so expensive to keep
updating that fewer and fewer garages are willing to undertake them.

Oh. Safety tests are performed by/at the DMV (called MVD in some states)
by \"state employees\". But, IIRC when I brought my vehicle into the
state, it was just a quick \"walk around\"... as if they were just counting
tires and making sure all of the lights worked.

[I\'ve a friend who had a piece of PVC pipe acting as a structural member
in his vehicle. No one ever took it off the road!]

Emissions testing, I think, is subcontracted to a private firm
(but uses a state owned facility?). It is largely a cookie-cutter
operation. Most vehicles pass (esp older ones!). The staff will
even try a few simple things to increase your chance of passing.

A failing test can be repeated (there are shops adjacent to the facility
that specialize in those types of repairs). And, once you\'ve spent
$X trying to come into compliance, you can get a waiver. (I\'m unsure
if the waiver is a vehicle-lifetime event -- as you would think it
would be -- or if this process has to be repeated annually... to screw
you over)

If this is going to be an annual job, it will be a non-trivial
addition to the running expenses.

I\'m looking at the *material* for use in another application.
If it routinely got cloudy, then I would want a way of easily
cleaning it (which would affect its designed shape) *or*
replacing it.

If you find one, let us know. This seems to be one of life\'s great
usolved problems.

Unfortunately, we don\'t know the criteria that was used to select
that particular material. Changing the criteria may make other
materials potential candidates.

Oncoming drivers kept flashing their headlights at me, even though mine
were on dipped beam and adjusted according to the manufacturer\'s
instructions.

SWMBO\'s vehicle got a similar reaction, initially. I feared the
lights weren\'t aimed properly so checked them, myself. I came
to realize their height (off the road surface) and being LEDs
made them appear brighter/higher.

This waan\'t a brightness problem, they were fitted with normal bulbs.
The design of the reflector was completely wrong with shafts of light
firing off in all directions. The manufacturer had obviously
concentrated on the central beam pattern and ignored everything outside
a 30-degree cone. Some beams were nearly vertical, others were at 45
degrees across the road and about 10 degrees above horizontal.

Here, the \"high beam\" is as much about WHERE (above the ground) the light
is aimed as it is about intensity. Modern lamps have a \"notch\" in
the visual field to assist in aiming. Verifying proper setting can
usually be done by the Average Joe... ensure fuel tank is full (?),
position vehicle X feet from an upright flat surface, measure location
of each notch relative to location of headlamp (the left -- oncoming
traffic -- side being angled inward to keep out of the other driver\'s
eyes).

I could see an obscuring plate inside the lens, but it appeared to have
been rivetted in place upside down, so it blocked the downward-reflected
beam and did not stop the upward-reflected beam.

Dual beam unit? Some vehicles, here, have two separate lamps;
one dual beam and the other just for \"high\".

The unit could not be
fitted the wrong way up, so the fault must have occurred during headlamp
manufacture. All the cars of that model and year had the same problem.
They passed the MOT test because the beam testing machines only measured
the central part of the beam.

Replacement lamps also exhibited the problem? Here, you can buy
aftermarket parts from manufacturers that are not the original \"OEM\".
So, one could hope a competitor released a \"compliant\" lamp that
was also *correct* (and ensured of a market addressing customers
like you)

You will sometimes see vehicles with blueish headlamps, or undercarriage
illumination, or... none being \"factory equipment\".

[My favorite are *spinners* -- but, that may be a cultural thing, locally]

<https://www.youtube.com/watch?v=TMyf0HpUv-0>
<https://www.youtube.com/watch?v=S1aaxgoaUwI>
<https://www.youtube.com/watch?v=0BX6Jm09hV8>

Always amusing to see how people spend their money! Unfortunately, there
are lots of rules -- many of which you won\'t realize until you are
cited for a violation! -- that limit what you can do to a vehicle
driven on public roads.

 

[Don Y]

On 2/21/2023 2:14 PM, Lasse Langwadt Christensen wrote:

But it definitely happen other things too. At work we have some curved skylights
that are plastic probably PC. Some of them, the old ones, are still clear. Those
that have been replaced later are all yellow

I replaced our skylights some years back. No \"yellowing\"
but they were incredibly brittle. They are available
in white opaque and brown tinted -- minimizing the solar
heat gain being a concern.

Unfortunately, they don\'t make any out of (safety) glass
as the shapes typically aren\'t \"planar\".

I wanted to install a 48x48\" in the kitchen -- to let in
OVERHEAD light -- but we \"voted on it\". Given that there
are just two of us, you can guess the outcome! :<

Majority rules!

 

[Carlos E. R.]

On 2023-02-21 19:27, Don Y wrote:

On 2/21/2023 5:09 AM, Carlos E. R. wrote:
On 2023-02-21 10:46, Liz Tuddenham wrote:
Don Y <blockedofcourse@foo.invalid> wrote:
On 2/20/2023 7:43 PM, Lasse Langwadt Christensen wrote:
tirsdag den 21. februar 2023 kl. 03.09.27 UTC+1 skrev Don Y:


On a previous car I found the beam pattern of the headlights was so bad
it dazzled oncoming drivers, and didn\'t illuminate the roadside verge.
Oncoming drivers kept flashing their headlights at me, even though mine
were on dipped beam and adjusted according to the manufacturer\'s
instructions.  I used to dread the slightest trace of fog because there
were shafts of light projecting upwards immediately in front of the
bonnet that lit up a dazzling curtain and blocked my view of the road.

In desperation I scrapped the fancy styled headlights and replaced them
with a black-painted rectangle of aluminium with a circular hole in the
middle.  Then I fitted a pair of ordinary 7-inch round halogen
headlights with glass lenses.  There were a few raised eyebrows from the
MOT tester, but the beam pattern was correct, so he issued a \'pass\'
certificate.

Any modification and here you do not pass. We have to replace with the
same model of fixture.

Here, each state comes up with their own rules (after initial manufacture).

Some places are PITAs and seem to go out of their way to put extra steps
in your way to make it harder for you to comply.  It\'s not that you *won\'t*
be able to comply but, rather, that you\'ll have to jump through a few
hoops along the way... that don\'t seem to serve any \"real purpose\"!

After initial registration, I don\'t think there is any ongoing requirement
for *proving* the road-worthiness/safety of a vehicle.  New vehicles are
pre-blessed by the manufacturer\'s compliance.

I\'ve lived in places (states) where I needed to be fingerprinted to
get a driver\'s license; places where the license had to be renewed
every ~4-5 years (some with \"driving tests\" as part of the process);
some where my license didn\'t require renewal for *30+* years;
places where I had to promptly change my registration to reflect my
residence in the state; some where a change of address could be
accommodated by \"taping a slip of paper with your NEW address onto
your existing credential\"; some where my vision test included tests for
colorblindness; some where vehicle age made it inherently harder to keep
it on the road; other places where it was *easier*; places where
registration was a flat fee; places where registration was based on
the current value of the vehicle -- or the available horsepower; etc.

Wow.

But, then again, the US is a geographically large area and the design
of our constitution intentionally tries to give rights to the individual
states, instead of imposing them from the federal level.

I heard

If you are born and raised in one particular area (state) and remain
there, you likely aren\'t even aware that things are different, elsewhere.

The modification transformed night driving and, of course, there were no
ageing problems with the glass lenses.

--
Cheers,
Carlos E.R.

 

[Don Y]

On 2/21/2023 3:29 PM, Carlos E. R. wrote:

[variations in licensing/registration requirements]

> Wow.

What throws many Americans is the notion that they are still
\"in the same country\" and expect laws, requirements, language,
etc. to remain constant (or, at least, consistent!). And,
it\'s not like there\'s a book/pamphlet to alert you to the
changes you\'d not expect!

[You (spain?) likely are keenly aware when you travel to
another european \"state\" and, likely, aware that the rules
likely change.]

In Boston, you wouldn\'t ask for a \"milkshake\" as that\'s
just \"flavored milk\"; what you really want is a frappe
(with ice cream!). You\'d buy your liquor at a \"liquor
store\" (where I grew up, it was called a *package* store
or \"packy\" in the vernacular). And, growing up, the
beer and wine sections of the refrigerated coolers
(need a different license to sell \"spirits\") would
be COVERED at 8:00PM (illegal to sell after 8!).

On my first visit to my wife\'s home town, I went to
cross the street to reach our destination directly
opposite -- only to be pulled back onto the curb:
\"You can\'t cross here!\"
\"Why not?\"
\"Jaywalking\"
\"Isn\'t that one of those laws that they keep
on the books just to be able to arrest mafioso
that they don\'t have any OTHER grounds to arrest?\"

In most places, a left turn traffic lane with its
own traffic signal is granted a \"green arrow\" before
oncoming traffic is allowed to proceed. After an
interval, that permission is revoked and normal
THRU traffic allowed to flow. Here, the left turn
signal *lags* the thru traffic - the thru traffic
is allowed to pass while the left turn traffic
is *nominally* restricted. Once the thru traffic
has been stopped -- and before the cross traffic
is allowed to go -- the left turn traffic is
permitted to turn, without worry of any other
traffic.

[While \"nominally restricted\", a flashing yellow arrow
can allow left turn traffic to proceed conditional
with the safety of doing so]

Out-of-towners are easily recognizable as such because
they turn left on red (expecting a \"leading left\" rule)
or remain stopped on a (lagging) left arrow.

 

[John Larkin]

On Tue, 21 Feb 2023 11:28:43 +0000, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:

Don Y <blockedofcourse@foo.invalid> wrote:

On 2/21/2023 2:46 AM, Liz Tuddenham wrote:
Wouldn\'t the sandpaper leave fine scratches in the material?

that\'s why you need multiple grits, you start with the coarsest to
thremove material and en each finer grit removes the scratches from the
thprevious grit. Sanding 101

I would still think that would leave scratches -- albeit very fine
ones. These wouldn\'t be present if a \"buffing wheel\" was used
(with a lubricating agent).

The kits contain a re-coating varnish which has a similar refrective
index to the lens material. This fills in any small residual scratches.

OK. So, it\'s not just to restore the UV protection.

I am tempted to say it is not *even* UV protection, based on my
experience.

[...]
After two years mine was so bad it got an \'advisory\' warning at the MOT

MOT = Department of Motor Vehicles?

Ministry of Transport Test: An annual test that is compulsory in the
UK. It started off sensibly with checks to see that the brakes worked
and the steering wasn\'t loose. Now it is an elaborate series of
bureaucratic hurdles that change every year and are so expensive to keep
updating that fewer and fewer garages are willing to undertake them.

In New Orleans, there was a vehicle inspection every six months, since
relaxed to annual I think. My Sprite usually failed because the
headlights were too low for the test machine.

When I moved to California, I was shocked to learn that there was no
regular vehicle inspection. Now we have a smog check every many years,
but that\'s all.

I\'ve been told that cars pass inspection in Germany if one leaves a
bribe on the back seat. Good liquor is effective.

 

[John Larkin]

On Tue, 21 Feb 2023 23:29:40 +0100, \"Carlos E. R.\"
<robin_listas@es.invalid> wrote:

On 2023-02-21 19:27, Don Y wrote:
On 2/21/2023 5:09 AM, Carlos E. R. wrote:
On 2023-02-21 10:46, Liz Tuddenham wrote:
Don Y <blockedofcourse@foo.invalid> wrote:
On 2/20/2023 7:43 PM, Lasse Langwadt Christensen wrote:
tirsdag den 21. februar 2023 kl. 03.09.27 UTC+1 skrev Don Y:


On a previous car I found the beam pattern of the headlights was so bad
it dazzled oncoming drivers, and didn\'t illuminate the roadside verge.
Oncoming drivers kept flashing their headlights at me, even though mine
were on dipped beam and adjusted according to the manufacturer\'s
instructions.  I used to dread the slightest trace of fog because there
were shafts of light projecting upwards immediately in front of the
bonnet that lit up a dazzling curtain and blocked my view of the road.

In desperation I scrapped the fancy styled headlights and replaced them
with a black-painted rectangle of aluminium with a circular hole in the
middle.  Then I fitted a pair of ordinary 7-inch round halogen
headlights with glass lenses.  There were a few raised eyebrows from the
MOT tester, but the beam pattern was correct, so he issued a \'pass\'
certificate.

Any modification and here you do not pass. We have to replace with the
same model of fixture.

Here, each state comes up with their own rules (after initial manufacture).

Some places are PITAs and seem to go out of their way to put extra steps
in your way to make it harder for you to comply.  It\'s not that you *won\'t*
be able to comply but, rather, that you\'ll have to jump through a few
hoops along the way... that don\'t seem to serve any \"real purpose\"!

After initial registration, I don\'t think there is any ongoing requirement
for *proving* the road-worthiness/safety of a vehicle.  New vehicles are
pre-blessed by the manufacturer\'s compliance.

I\'ve lived in places (states) where I needed to be fingerprinted to
get a driver\'s license; places where the license had to be renewed
every ~4-5 years (some with \"driving tests\" as part of the process);
some where my license didn\'t require renewal for *30+* years;
places where I had to promptly change my registration to reflect my
residence in the state; some where a change of address could be
accommodated by \"taping a slip of paper with your NEW address onto
your existing credential\"; some where my vision test included tests for
colorblindness; some where vehicle age made it inherently harder to keep
it on the road; other places where it was *easier*; places where
registration was a flat fee; places where registration was based on
the current value of the vehicle -- or the available horsepower; etc.

Wow.


But, then again, the US is a geographically large area and the design
of our constitution intentionally tries to give rights to the individual
states, instead of imposing them from the federal level.

I heard

Competition works.

 

[bitrex]

On 2/21/2023 7:32 PM, Don Y wrote:

On 2/21/2023 3:29 PM, Carlos E. R. wrote:

[variations in licensing/registration requirements]

Wow.

What throws many Americans is the notion that they are still
\"in the same country\" and expect laws, requirements, language,
etc. to remain constant (or, at least, consistent!).  And,
it\'s not like there\'s a book/pamphlet to alert you to the
changes you\'d not expect!

[You (spain?) likely are keenly aware when you travel to
another european \"state\" and, likely, aware that the rules
likely change.]

In Boston, you wouldn\'t ask for a \"milkshake\" as that\'s
just \"flavored milk\"; what you really want is a frappe
(with ice cream!).  You\'d buy your liquor at a \"liquor
store\" (where I grew up, it was called a *package* store
or \"packy\" in the vernacular).  And, growing up, the
beer and wine sections of the refrigerated coolers
(need a different license to sell \"spirits\") would
be COVERED at 8:00PM (illegal to sell after 8!).

I think \"frappe\" is pretty out-of-fashion unless one\'s really of the old
New England breed, I don\'t hear it much among people under 50 even ones
who were born here. Nobody\'s going to be confused as to what\'s being
asked for if someone from elsewhere orders a \"milkshake.\"

\"Blinker\" and \"packy\" are still common, though