\"Headlight\" polishing...

[Lasse Langwadt Christensen]

onsdag den 22. februar 2023 kl. 01.45.56 UTC+1 skrev John Larkin:

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

Don Y <blocked...@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.

here car inspection (every two years once the car is 4 years old) is now all done private companies,
but they are monitored and randomly tested. If someone takes bribes it is pretty quickly found out.
They have all the statistics of what cars usually fail for and if that doesn\'t happen they now
something is up

they check lights, tires, brakes, steering, rust in critical areas, check engine for emissions leaks and such
but since it only cost ~$60 it\'s not like they spend a long time on each car

 

[Don Y]

On 2/21/2023 6:07 PM, bitrex wrote:

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.\"

I\'ve not lived (or *been*) in beantown in 40+ years. So, my
experiences, there, are admittedly dated. :>

I do recall a pamphlet prepared (tongue-in-cheek) for foreign
students with things like \"traffic lights are only advisory\"...

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

And rotaries? Turnpikes? Parkways?

[Around here, all would be met with blank stares]

 

[Don Y]

On 2/21/2023 6:53 PM, Don Y wrote:

On 2/21/2023 6:07 PM, bitrex wrote:
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.\"

I\'ve not lived (or *been*) in beantown in 40+ years.  So, my
experiences, there, are admittedly dated.  :

Where (approx) are you located?

I do recall a pamphlet prepared (tongue-in-cheek) for foreign
students with things like \"traffic lights are only advisory\"...

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

And rotaries?  Turnpikes?  Parkways?

[Around here, all would be met with blank stares]

 

[John Larkin]

On Tue, 21 Feb 2023 18:53:44 -0700, Don Y
<blockedofcourse@foo.invalid> wrote:

On 2/21/2023 6:07 PM, bitrex wrote:
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.\"

I\'ve not lived (or *been*) in beantown in 40+ years. So, my
experiences, there, are admittedly dated. :

I do recall a pamphlet prepared (tongue-in-cheek) for foreign
students with things like \"traffic lights are only advisory\"...

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

And rotaries? Turnpikes? Parkways?

Roundabouts. Traffic circles. Freeways.

[Around here, all would be met with blank stares]

We have \"traffic islands\" in the middle of big streets. In New
Orleans, they are called \"neutral grounds.\" We have palm trees on
ours, they have oaks. We both have streetcars.

We have cable cars too!

The old timers in New Orleans called a sidewalk a \"banquette\",
pronounced bank-it.

San Francisco recently made it legal to jay walk. Stop signs have
become only suggestive.

 

[Martin Brown]

On 20/02/2023 18:30, 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?]

I suspect most do now use polycarbonate outer casings.

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]

I suspect on the majority of cars these days the outer shell of the
light fittings is some sort of water clear (or coloured) polycarbonate
plastic. It has to be UV protected or it will go brittle in sunlight.

Glass is tough enough to only suffer chips when it takes a serious hit
from stones and grit but plastic can be hazed by almost anything
impacting it (and seriously damaged by some solvents). Methanol attacks
for most plastics and petrol can do the same for polycarbonate.

If you can scratch the surface with a shard of bottle glass then it
isn\'t made of glass (may devalue your fitting). Rear light clusters are
almost always some sort of polycarbonate I think. Water clear epoxy will
repair them but UV damage turns it yellow after a while.

Any organic solvent will quite likely turn a minor scratch into serious
deep cracks through the material so your only option is physical removal
of the surface crazing by rubbing compound followed by a new protective
UV coat (or leave well alone and live with cosmetic damage).

You might get away with a high viscosity silicone oil as a way of hiding
the hazing by filling the gaps rather than removing it.

Cosmetic defects on my headlights doesn\'t really bother me that much.

--
Martin Brown

 

[Liz Tuddenham]

Martin Brown <\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 20/02/2023 18:30, 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?]

I suspect most do now use polycarbonate outer casings.

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]

I suspect on the majority of cars these days the outer shell of the
light fittings is some sort of water clear (or coloured) polycarbonate
plastic. It has to be UV protected or it will go brittle in sunlight.

I think the recycling information on the back of my van headlamps
(Toyota) says the lenses are PMMA. I\'ll check next time I have to take
them out.

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

 

[Martin Brown]

On 24/02/2023 10:09, Liz Tuddenham wrote:

Martin Brown <\'\'\'newspam\'\'\'@nonad.co.uk> wrote:


I suspect on the majority of cars these days the outer shell of the
light fittings is some sort of water clear (or coloured) polycarbonate
plastic. It has to be UV protected or it will go brittle in sunlight.

I think the recycling information on the back of my van headlamps
(Toyota) says the lenses are PMMA. I\'ll check next time I have to take
them out.

I confess that my assumption was PMMA for the rear light clusters until
I tried to repair a crack using my PMMA glue and it failed dismally.
Polycarbonate is a lot more resilient to impacts and so I would expect
it to be used on the front too where the impact risk is much higher.

I don\'t obsess about polishing my headlights though.
My car is lucky if it gets washed once every other month!

--
Martin Brown

 

[Martin Brown]

On 22/02/2023 00:45, John Larkin wrote:

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.

Possible I suppose but I always think of Germans and Dutch engineers as
rather proper play by the rules types. Belgium was another story!

In Belgium the corruption of garages doing MOT\'s was so bad that they
had put the entire scheme under government supervision at special custom
built sites. I took our car through one - it was entertaining...

When we lived in Belgium there was a massive scandal of PCBs and dioxins
in eggs and poultry (not that it affected us we had our own). The guy
who got prosecuted at first was a scientist for leaking his findings to
the press after the government sat on them for 9 weeks by which time
most of the dangerously contaminated chicken and eggs had been eaten!

It is used as a case study in \"How not to do crisis communications\" eg

https://www.gmpplus.org/media/mr2hv24r/link-h2-11-verkest-article.pdf
(it is in English despite the URL title)

--
Martin Brown

 

[Dean Hoffman]

On Friday, February 24, 2023 at 2:12:41 PM UTC-6, Martin Brown wrote:

On 22/02/2023 00:45, John Larkin wrote:
On Tue, 21 Feb 2023 11:28:43 +0000, l...@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:

Don Y <blocked...@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.
Possible I suppose but I always think of Germans and Dutch engineers as
rather proper play by the rules types. Belgium was another story!

In Belgium the corruption of garages doing MOT\'s was so bad that they
had put the entire scheme under government supervision at special custom
built sites. I took our car through one - it was entertaining...

When we lived in Belgium there was a massive scandal of PCBs and dioxins
in eggs and poultry (not that it affected us we had our own). The guy
who got prosecuted at first was a scientist for leaking his findings to
the press after the government sat on them for 9 weeks by which time
most of the dangerously contaminated chicken and eggs had been eaten!

It is used as a case study in \"How not to do crisis communications\" eg

https://www.gmpplus.org/media/mr2hv24r/link-h2-11-verkest-article.pdf
(it is in English despite the URL title)

--
Martin Brown

Nebraska, USA had annual inspections. The fee was mandated at $3/inspection or so.
The gas/service stations lost money doing them. The vehicle passed if the lights worked and the wipers hadn\'t fallen off as a result.
At least one state required all vehicles to run with headlights on during the day. The lawmakers noticed that motorcycles stood out on the roads because bikers usually ran with theirs on. Well, if a little is good, a lot is better reasoned the lawmakers. Not so in the real world.
I don\'t remember if motorcycles were inspected.

 

[Don Y]

On 2/24/2023 2:13 AM, Martin Brown wrote:

On 20/02/2023 18:30, 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?]

I suspect most do now use polycarbonate outer casings.

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]

I suspect on the majority of cars these days the outer shell of the light
fittings is some sort of water clear (or coloured) polycarbonate plastic. It
has to be UV protected or it will go brittle in sunlight.

Glass is tough enough to only suffer chips when it takes a serious hit from
stones and grit but plastic can be hazed by almost anything impacting it (and
seriously damaged by some solvents). Methanol attacks for most plastics and
petrol can do the same for polycarbonate.

If you can scratch the surface with a shard of bottle glass then it isn\'t made
of glass (may devalue your fitting). Rear light clusters are almost always some
sort of polycarbonate I think. Water clear epoxy will repair them but UV damage
turns it yellow after a while.

Any organic solvent will quite likely turn a minor scratch into serious deep
cracks through the material so your only option is physical removal of the
surface crazing by rubbing compound followed by a new protective UV coat (or
leave well alone and live with cosmetic damage).

You might get away with a high viscosity silicone oil as a way of hiding the
hazing by filling the gaps rather than removing it.

Cosmetic defects on my headlights doesn\'t really bother me that much.

I\'m not interested in headlights (our car is garaged, driven very little
and probably sees less than a few hundred hours of sunlight -- including
driven time plus time spent sitting in unprotected parking lots -- each
year).

But, I am concerned about the characteristics of the *material*.

Glass would be ideal -- but is costly to \"mold\", esp in larger sizes.
It\'s clear, heat/solvent/abrasion/UV resistant, a decent insulator,
easily cleaned (regardless of shape), etc.

Plastics are easier/cheaper to fabricate in different shapes.
But, have downsides (as apparent, here).

As the car companies settled on this material -- presumably
after an extensive evaluation of alternative materials (likely
including glass) -- I figured that was a good starting point.

Yet, see cars with this \"fog problem\" so imagine any use that
I make of the same material will, eventually, suffer from the
same problem. Thus, either come up with an easy way of
cleaning/refinishing the items. Or, an easy way of replacing them.

Or, an alternate material.

 

[Don Y]

On 2/24/2023 7:02 AM, Martin Brown wrote:
> My car is lucky if it gets washed once every other month!

I wash every 3 months and wax on every other wash.
But, the car sees very little \"exposure\" so the
wash is largely to get the airborne dirt (dust) off
the vehicle.

This is especially problematic during Monsoon...
when it seems it *rains* dirt! :<

 

[John Larkin]

On Fri, 24 Feb 2023 12:26:01 -0800 (PST), Dean Hoffman
<deanh6929@gmail.com> wrote:

On Friday, February 24, 2023 at 2:12:41?PM UTC-6, Martin Brown wrote:
On 22/02/2023 00:45, John Larkin wrote:
On Tue, 21 Feb 2023 11:28:43 +0000, l...@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:

Don Y <blocked...@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.
Possible I suppose but I always think of Germans and Dutch engineers as
rather proper play by the rules types. Belgium was another story!

In Belgium the corruption of garages doing MOT\'s was so bad that they
had put the entire scheme under government supervision at special custom
built sites. I took our car through one - it was entertaining...

When we lived in Belgium there was a massive scandal of PCBs and dioxins
in eggs and poultry (not that it affected us we had our own). The guy
who got prosecuted at first was a scientist for leaking his findings to
the press after the government sat on them for 9 weeks by which time
most of the dangerously contaminated chicken and eggs had been eaten!

It is used as a case study in \"How not to do crisis communications\" eg

https://www.gmpplus.org/media/mr2hv24r/link-h2-11-verkest-article.pdf
(it is in English despite the URL title)

--
Martin Brown

Nebraska, USA had annual inspections. The fee was mandated at $3/inspection or so.
The gas/service stations lost money doing them. The vehicle passed if the lights worked and the wipers hadn\'t fallen off as a result.
At least one state required all vehicles to run with headlights on during the day. The lawmakers noticed that motorcycles stood out on the roads because bikers usually ran with theirs on. Well, if a little is good, a lot is better reasoned the lawmakers. Not so in the real world.
I don\'t remember if motorcycles were inspected.

When I was in Moscow, it was a rule that cars couldn\'t run their
headlights at night in the city... only on the highways out of town.

People would park anywhere, on sidewalks or whatever, and pedestrians
were fair game targets.

Drivers did get tickets for having dirty cars. It was normal to carry
something to bribe the cops with. I hung out with a musician who gave
away his records.

People only installed windshield wipers when they drove in the rain,
or else they would be stolen.

 

[Don Y]

On 2/24/2023 1:26 PM, Dean Hoffman wrote:

Nebraska, USA had annual inspections. The fee was mandated at $3/inspection
or so.

The gas/service stations lost money doing them. The vehicle passed if the
lights worked and the wipers hadn\'t fallen off as a result.

At least one state required all vehicles to run with headlights on during
the day. The lawmakers noticed that motorcycles stood out on the roads
because bikers usually ran with theirs on. Well, if a little is good, a
lot is better reasoned the lawmakers. Not so in the real world. I don\'t
remember if motorcycles were inspected.

Likely not. With half as many wheels, they were half as likely to
have any \"issues\", right? <rolls eyes>

I\'ve toyed with the idea of getting a bike, here. But, too many
crazy drivers that fail to see anything smaller than a Mack truck
(i.e., only worry about things that can hurt *them*!)

Bicycles are suicide. Motorcycles only slightly less so. And,
don\'t even THINK of a moped or scooter (worst of both worlds).
We see a fair number of recumbent bikes -- with tall \"flags\"
attached in the hope of making them more visible. Good luck
with that!

I wonder where trikes fit in the mix? And, just what you can
ride on a *sidewalk*...

 

[Lasse Langwadt Christensen]

fredag den 24. februar 2023 kl. 21.26.06 UTC+1 skrev Dean Hoffman:

On Friday, February 24, 2023 at 2:12:41 PM UTC-6, Martin Brown wrote:
On 22/02/2023 00:45, John Larkin wrote:
On Tue, 21 Feb 2023 11:28:43 +0000, l...@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:

Don Y <blocked...@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.
Possible I suppose but I always think of Germans and Dutch engineers as
rather proper play by the rules types. Belgium was another story!

In Belgium the corruption of garages doing MOT\'s was so bad that they
had put the entire scheme under government supervision at special custom
built sites. I took our car through one - it was entertaining...

When we lived in Belgium there was a massive scandal of PCBs and dioxins
in eggs and poultry (not that it affected us we had our own). The guy
who got prosecuted at first was a scientist for leaking his findings to
the press after the government sat on them for 9 weeks by which time
most of the dangerously contaminated chicken and eggs had been eaten!

It is used as a case study in \"How not to do crisis communications\" eg

https://www.gmpplus.org/media/mr2hv24r/link-h2-11-verkest-article.pdf
(it is in English despite the URL title)

--
Martin Brown
Nebraska, USA had annual inspections. The fee was mandated at $3/inspection or so.
The gas/service stations lost money doing them. The vehicle passed if the lights worked and the wipers hadn\'t fallen off as a result.
At least one state required all vehicles to run with headlights on during the day. The lawmakers noticed that motorcycles stood out on the roads because bikers usually ran with theirs on. Well, if a little is good, a lot is better reasoned the lawmakers. Not so in the real world.

daylight running lights are required all over Europe, and it makes a huge difference.
Unfortunately some numb-nut decided that to save energy it should only be on the front,
so lot of cars driving around in the dark with no rear lights because they forget to turn on the lights
That was then \"fixed\" by requiring all new cars have automatic lights, which doesn\'t understand fog or rain

> I don\'t remember if motorcycles were inspected.

here car are inspected every two years, motorcycles only when you sell it to someone else

 

[Lasse Langwadt Christensen]

fredag den 24. februar 2023 kl. 22.38.00 UTC+1 skrev Don Y:

On 2/24/2023 1:26 PM, Dean Hoffman wrote:
Nebraska, USA had annual inspections. The fee was mandated at $3/inspection
or so.

The gas/service stations lost money doing them. The vehicle passed if the
lights worked and the wipers hadn\'t fallen off as a result.

At least one state required all vehicles to run with headlights on during
the day. The lawmakers noticed that motorcycles stood out on the roads
because bikers usually ran with theirs on. Well, if a little is good, a
lot is better reasoned the lawmakers. Not so in the real world. I don\'t
remember if motorcycles were inspected.
Likely not. With half as many wheels, they were half as likely to
have any \"issues\", right? <rolls eyes

sorta, they aren\'t likely to have the chassis rotted out or a bunch of suspension
and steering links ready to fall apart

I\'ve toyed with the idea of getting a bike, here. But, too many
crazy drivers that fail to see anything smaller than a Mack truck
(i.e., only worry about things that can hurt *them*!)

Bicycles are suicide. Motorcycles only slightly less so. And,
don\'t even THINK of a moped or scooter (worst of both worlds).
We see a fair number of recumbent bikes -- with tall \"flags\"
attached in the hope of making them more visible. Good luck
with that!

depends on where you are, in some place the only sensible way to get around is
by bicycle, (with electric assist if you don\'t want to pedal so much)

https://img2.thejournal.ie/article/4785733/river

I wonder where trikes fit in the mix? And, just what you can
ride on a *sidewalk*...

sidewalks are for walking

 

[Martin Brown]

On 24/02/2023 20:43, Don Y wrote:

On 2/24/2023 2:13 AM, Martin Brown wrote:

If you can scratch the surface with a shard of bottle glass then it
isn\'t made of glass (may devalue your fitting). Rear light clusters
are almost always some sort of polycarbonate I think. Water clear
epoxy will repair them but UV damage turns it yellow after a while.

Any organic solvent will quite likely turn a minor scratch into
serious deep cracks through the material so your only option is
physical removal of the surface crazing by rubbing compound followed
by a new protective UV coat (or leave well alone and live with
cosmetic damage).

You might get away with a high viscosity silicone oil as a way of
hiding the hazing by filling the gaps rather than removing it.

Cosmetic defects on my headlights doesn\'t really bother me that much.

I\'m not interested in headlights (our car is garaged, driven very little
and probably sees less than a few hundred hours of sunlight -- including
driven time plus time spent sitting in unprotected parking lots -- each
year).

But, I am concerned about the characteristics of the *material*.

OK. So is the problem to make a clear optical envelope of some sort to
contain a device and protect it from the elements outdoors.
How important is it that the thing remains optically clear?

Flame polishing sometimes works OK for glass but using it on a flammable
clear plastic could be rather exciting in the wrong hands.

https://en.wikipedia.org/wiki/Flame_polishing

Glass would be ideal -- but is costly to \"mold\", esp in larger sizes.
It\'s clear, heat/solvent/abrasion/UV resistant, a decent insulator,
easily cleaned (regardless of shape), etc.

Plastics are easier/cheaper to fabricate in different shapes.
But, have downsides (as apparent, here).

The main downsides are being much softer than glass, prone to damage by
the wrong solvent cleaner (remember the plexiglass aquarium failure?).

I think UV stability on treated plastics should be OK unless you are
driving them around at speed in a hot desert full of sand.

As the car companies settled on this material -- presumably
after an extensive evaluation of alternative materials (likely
including glass) -- I figured that was a good starting point.

Yet, see cars with this \"fog problem\" so imagine any use that
I make of the same material will, eventually, suffer from the
same problem.  Thus, either come up with an easy way of
cleaning/refinishing the items.  Or, an easy way of replacing them.

Plastics exposed to sunlight at low latitudes, UV and/or ozone will
either yellow, go brittle or craze - often a combination of all three.
Unprotected water clear epoxy goes yellow in about 3 years here.

I suspect in your conditions they go downhill pretty rapidly once the UV
coating has worn off due to being sand blasted by desert sand and grit.

> Or, an alternate material.

Perspex or polycarbonate are the two materials of choice for this.
Which one is better for your requirements is another matter.

What sort of working lifetime are you aiming for?
How exposed to direct sunlight?


--
Martin Brown

 

[Don Y]

On 2/24/2023 3:10 PM, Lasse Langwadt Christensen wrote:

Bicycles are suicide. Motorcycles only slightly less so. And,
don\'t even THINK of a moped or scooter (worst of both worlds).
We see a fair number of recumbent bikes -- with tall \"flags\"
attached in the hope of making them more visible. Good luck
with that!

depends on where you are, in some place the only sensible way to get around is
by bicycle, (with electric assist if you don\'t want to pedal so much)

We have extensive \"bike paths\" through town. But, they are largely
recreational -- you won\'t be able to directly access any businesses,
medical facilities, etc. via them.

> https://img2.thejournal.ie/article/4785733/river

Here, the more common approach is a small ICE mounted on the
bicycle.

I wonder where trikes fit in the mix? And, just what you can
ride on a *sidewalk*...

sidewalks are for walking

Yes, yet I can legally operate my electric wheelchair on them!
The law doesn\'t say that I have to medically NEED the wheelchair...

And, I suspect these \"one wheels\" and electric/ICE skateboards
probably fall in that grey area, as well.

 

[Don Y]

On 2/24/2023 2:50 PM, Lasse Langwadt Christensen wrote:
> daylight running lights are required all over Europe, and it makes a huge difference.

Running lights, here, are not the same as having your *headlights* on.
They are typically far less light output... almost as if your turn signal
was permanently illuminated. Almost *decorative*!

Unfortunately some numb-nut decided that to save energy it should only be on the front,
so lot of cars driving around in the dark with no rear lights because they forget to turn on the lights
That was then \"fixed\" by requiring all new cars have automatic lights, which doesn\'t understand fog or rain

We can select from on, off and automatic. So, it\'s still possible to
drive, at night, without lights.

 

[Lasse Langwadt Christensen]

lørdag den 25. februar 2023 kl. 00.21.40 UTC+1 skrev Don Y:

On 2/24/2023 2:50 PM, Lasse Langwadt Christensen wrote:
daylight running lights are required all over Europe, and it makes a huge difference.
Running lights, here, are not the same as having your *headlights* on.
They are typically far less light output... almost as if your turn signal
was permanently illuminated. Almost *decorative*!

here you can use either, just need (front) lights on all the time

Unfortunately some numb-nut decided that to save energy it should only be on the front,
so lot of cars driving around in the dark with no rear lights because they forget to turn on the lights
That was then \"fixed\" by requiring all new cars have automatic lights, which doesn\'t understand fog or rain
We can select from on, off and automatic. So, it\'s still possible to
drive, at night, without lights.

sure, but if you have the front lights on all the time it is easy to forget that you don\'t have the rear lights on
unless their are automatic or you turn them on manually

 

[Lasse Langwadt Christensen]

lørdag den 25. februar 2023 kl. 00.19.24 UTC+1 skrev Don Y:

On 2/24/2023 3:10 PM, Lasse Langwadt Christensen wrote:
Bicycles are suicide. Motorcycles only slightly less so. And,
don\'t even THINK of a moped or scooter (worst of both worlds).
We see a fair number of recumbent bikes -- with tall \"flags\"
attached in the hope of making them more visible. Good luck
with that!

depends on where you are, in some place the only sensible way to get around is
by bicycle, (with electric assist if you don\'t want to pedal so much)
We have extensive \"bike paths\" through town. But, they are largely
recreational -- you won\'t be able to directly access any businesses,
medical facilities, etc. via them.

https://img2.thejournal.ie/article/4785733/river

Here, the more common approach is a small ICE mounted on the
bicycle.

here that would be a moped, and it would need to type approved as
such from the manufacturer and you need to have liability insurance
and wear a helmet and if you were born after 1995 you need to have
some form of drivers license

I wonder where trikes fit in the mix? And, just what you can
ride on a *sidewalk*...

sidewalks are for walking
Yes, yet I can legally operate my electric wheelchair on them!
The law doesn\'t say that I have to medically NEED the wheelchair...

And, I suspect these \"one wheels\" and electric/ICE skateboards
probably fall in that grey area, as well.

here they are, for now, classified as pedetrians