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wiedemann
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 Posted: Mon Oct 06, 2008 3:17 pm Post subject: Restoring Automotive Tail Lamps |
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After a recent bulb replacement, I noticed that the reflective coating
in the tail lamps of my late nineties Honda Civic is beginning to
flake off. Bulbs are stock wattage and so I believe this
deterioration is simply due to age. Rather than discard a otherwise
intact set, are there any spray coatings available to a DIYer that
could restore functionality to these tail lamps? If it helps at all,
the reflectors in the tail lamp are not faceted.
I have found Krylon>s Reflect-A-Lite product
(http://www.kpg-industrial.com/products/reflectalite_spray_paint) as
well as Eastwood>s chrome galvanized
(http://www.eastwoodco.com/jump.jsp?itemID=18815&itemType=PRODUCT) and
reflective aluminum
(http://www.eastwoodco.com/jump.jsp?itemID=99&itemType=PRODUCT)
aerosols. I am not sure which would be the best option or if there
are any other products worth considering.
I thank the group in advance for any insight it may provide.
-- |
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Boxman
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| Posted: Mon Oct 06, 2008 3:17 pm Post subject: Re: Restoring Automotive Tail Lamps |
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On Oct 6, 5:17 am, wiedemann <nos...@please.com> wrote:
[quote]After a recent bulb replacement, I noticed that the reflective coating
in the tail lamps of my late nineties Honda Civic is beginning to
flake off. Bulbs are stock wattage and so I believe this
deterioration is simply due to age. Rather than discard a otherwise
intact set, are there any spray coatings available to a DIYer that
could restore functionality to these tail lamps? If it helps at all,
the reflectors in the tail lamp are not faceted.
I have found Krylon>s Reflect-A-Lite product
(http://www.kpg-industrial.com/products/reflectalite_spray_paint) as
well as Eastwood>s chrome galvanized
(http://www.eastwoodco.com/jump.jsp?itemID=18815&itemType=PRODUCT) and
reflective aluminum
(http://www.eastwoodco.com/jump.jsp?itemID=99&itemType=PRODUCT)
aerosols. I am not sure which would be the best option or if there
are any other products worth considering.
I thank the group in advance for any insight it may provide.
--
[/quote]
Usually the tail lamps are coated with either a metallic coating or a
painted on coating. If it looks like a shiny metal then it was
originally vacuum metallized with aluminum which has about 85%
reflectivity depending on which plastic it was applied to. It will be
hard to duplicate that with paint - in fact you won>t be able to.
If on the other hand it is painted (it should look more diffuse) ,then
those paints are usually specialty paints from a company like RedSpot
that offer higher reflectivity than you can generally find on a store
shelf. These paints can have reflectivities of 65% or better. Most
paints off the shelf won>t reach that level of reflectivity
If your lamp surface is originally metallized and degraded
significantly then painting it may restore some function, but will not
return it to original condition. If it is just flaking in a few
spots, you might be better off just leaving it alone as paint will
drop the light output significantly compared to the original. If it
was originally painted and is flaking, then painting it might be
somewhat helpful.
One question, though, how do you plan to get the lens off to do the
repair? If it is a late nineties lamp, the glue may be an epoxy,
which will make it difficult (if not impossible) to get the lens off
and reassemble after you open the lamp, or the lens may be welded on
which will make it difficult to get off and put back togeteher. The
big problem would be making sure you have the lens sealed after your
repair so that you don>t get water in the lamps and ruin any repair
you did do on the reflector or burn out bulbs at a faster pace because
of the water.
Also might want to make sure any paint you do use can withstand fairly
high temperatures without outgassing. The bulbs can put out a lot of
heat in that small space and you wouldn>t want to have your lamp fog
up from outgassing of the paint. |
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Joe
Guest
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| Posted: Mon Oct 06, 2008 6:26 pm Post subject: Re: Restoring Automotive Tail Lamps |
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On Mon, 06 Oct 2008 05:17:02 -0500, wiedemann <nospam@please.com>
wrote:
[quote]After a recent bulb replacement, I noticed that the reflective coating
in the tail lamps of my late nineties Honda Civic is beginning to
flake off. Bulbs are stock wattage and so I believe this
deterioration is simply due to age. Rather than discard a otherwise
intact set, are there any spray coatings available to a DIYer that
could restore functionality to these tail lamps? If it helps at all,
the reflectors in the tail lamp are not faceted.
I have found Krylon>s Reflect-A-Lite product
(http://www.kpg-industrial.com/products/reflectalite_spray_paint) as
well as Eastwood>s chrome galvanized
(http://www.eastwoodco.com/jump.jsp?itemID=18815&itemType=PRODUCT) and
reflective aluminum
(http://www.eastwoodco.com/jump.jsp?itemID=99&itemType=PRODUCT)
aerosols. I am not sure which would be the best option or if there
are any other products worth considering.
I thank the group in advance for any insight it may provide.
[/quote]
Not exactly what you are asking for, but I painted the inside of the
taillight in my '50 HD Panhead with a gloss white paint. It actually
spread the lit area more evenly across the lens. It sure seemed to be
more visible, and, since motorcycles are at a distinct disadvantage at
night anyway, I was happy.
If you use a reflective paint, check that the coating appears
specular. If it doesn>t have a mirror-like finish, you are undoubtedly
losing some of the light to absorption.
Joe |
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Boxman
Guest
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| Posted: Tue Oct 07, 2008 3:31 am Post subject: Re: Restoring Automotive Tail Lamps |
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On Oct 6, 6:30 pm, wiedemann <nos...@please.com> wrote:
[quote]On Mon, 6 Oct 2008 07:02:24 -0700 (PDT), Boxman <box...@voyager.net
wrote:
Usually the tail lamps are coated with either a metallic coating or a
painted on coating. If it looks like a shiny metal then it was
originally vacuum metallized with aluminum which has about 85%
reflectivity depending on which plastic it was applied to. It will be
hard to duplicate that with paint - in fact you won>t be able to.
If on the other hand it is painted (it should look more diffuse) ,then
those paints are usually specialty paints from a company like RedSpot
that offer higher reflectivity than you can generally find on a store
shelf. These paints can have reflectivities of 65% or better. Most
paints off the shelf won>t reach that level of reflectivity
If your lamp surface is originally metallized and degraded
significantly then painting it may restore some function, but will not
return it to original condition. If it is just flaking in a few
spots, you might be better off just leaving it alone as paint will
drop the light output significantly compared to the original. If it
was originally painted and is flaking, then painting it might be
somewhat helpful.
One question, though, how do you plan to get the lens off to do the
repair? If it is a late nineties lamp, the glue may be an epoxy,
which will make it difficult (if not impossible) to get the lens off
and reassemble after you open the lamp, or the lens may be welded on
which will make it difficult to get off and put back togeteher. The
big problem would be making sure you have the lens sealed after your
repair so that you don>t get water in the lamps and ruin any repair
you did do on the reflector or burn out bulbs at a faster pace because
of the water.
Also might want to make sure any paint you do use can withstand fairly
high temperatures without outgassing. The bulbs can put out a lot of
heat in that small space and you wouldn>t want to have your lamp fog
up from outgassing of the paint.
This is all very good information; thank you. The lamp surface looks
to be painted as it is not nearly as it is much duller than a
headlamp. I took some pictures of the damage to give a better idea:
Picture 1 - http://tinypic.com/view.php?pic=2j4d10l&s=4
Picture 2 - http://tinypic.com/view.php?pic=jkxa4n&s=4
This was with a stock wattage bulb and there was no water in the tail
lamps during my ownership (purchased the car used two years ago).
To remove the lens from the tail lamp, I plan on heating it up in the
oven briefly and then separating the two once the sealant becomes weak
enough. The process seems to work well enough for the people adding
ccfl tubes in their headlamps for pseudo-BMW "angel eyes." I believe
RTV sealant should be sufficient to seal the halves back together.
It is discouraging that an OEM tail lamp would deteroriate after so
few years. How does Stanley, the manufacturer of the lamp, generally
compare to other manufacturers such as Hella and Valeo?
It looks like I>ll go with Eastwood>s chrome galvanized aerosol as it
can withstand temperatures of up to 300 degrees F.
As an aside, is the reason why we see much less opaque tail lamps
lenses today because of the switch from painted to vacuum metallized
reflectors? One example that comes to mind is the difference between
the tail lamps between a 1996-1998 Honda Civic sedan and a 1999-2000.
Pictures for reference:
96-98:http://tinypic.com/view.php?pic=qx2s5f&s=4
99-00:http://tinypic.com/view.php?pic=i3didx&s=4
In any case, thanks again for the help.
--
[/quote]
It>s a little hard to tell from the pictures, but the flaking looks
more like paint than metallizing to me too.
I have a 2000 honda accord that has paint in the rear lamps and it is
flaking also (no water damage). I don>t remember the entire lighting
regulation, but there is some testing that would have had to pass with
regards to temperature cycling etc. where there should be essentially
no degradation of the light output. I>m sure the paint used by the
OEM for your lamps passes those specs, but those specs may not
adequately represent long term performance of say more than 5 years of
use. The longevity of the paint would be dependent on formulation
used and application conditions.
It>s hard to make comparisons between manufacturers as each one has
probably had issues at one time or another. Having worked in the
field, I can say that the major manufacturers all have good quality
systems in place and do a lot of testing before putting a lamp into
production. A lot of the suppliers of materials used in the lamps
serve all or most of the lamp manufacturers. So the lamp
manufacturers usually have access to the same material technologies at
one point or another.
The switch to less opaque rear lamps I think is primarily driven by
styling demands for a more jewel like appearance from the rear lamps.
The use of metallizing is pretty much required if you want to show the
optics as part of the styling theme on the rear lamps. Painting was
probably used more frequently in older products because it generally
could be done cheaper than a metallized lamp and if you weren>t going
to see the surface through the lens, why spend the extra money.
When you go to disassemble your lamp, you may not be able to heat it
up to get it apart. Rear lamps commonly use different adhesives from
headlamps. The headlamps that you referred to that you can heat in an
oven and pry apart use a form of hot melt glue that will become
plastic enough again with heat to allow for the lamp to be
disassembled. The adhesive used in rear lamps are sometimes
thermosetting, which means that it won>t become pliable with heat. If
you find that to be the case, you>re kind of stuck - you>re only
option would be to cut the lamp open. Chances are your lamp is made
of acrylic for the lens and ABS or ASA for the housing. If you look
up the Heat Deflection Temperature (HDT) for those materials that
will give you a guide for how hot you can make the oven to try and
heat the lamp to get it apart. I don>t remember them off the top of
my head so I won>t stand by the numbers, but you probably can>t go
much above 175-200 degrees F without potentially melting the
plastic.
Good luck with your project. If all else fails you can canvas your
local salvage yard and try to find some without flaking and talk the
salvage guy into a cheap price. |
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wiedemann
Guest
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| Posted: Tue Oct 07, 2008 4:30 am Post subject: Re: Restoring Automotive Tail Lamps |
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On Mon, 6 Oct 2008 07:02:24 -0700 (PDT), Boxman <boxman@voyager.net>
wrote:
[quote]Usually the tail lamps are coated with either a metallic coating or a
painted on coating. If it looks like a shiny metal then it was
originally vacuum metallized with aluminum which has about 85%
reflectivity depending on which plastic it was applied to. It will be
hard to duplicate that with paint - in fact you won>t be able to.
If on the other hand it is painted (it should look more diffuse) ,then
those paints are usually specialty paints from a company like RedSpot
that offer higher reflectivity than you can generally find on a store
shelf. These paints can have reflectivities of 65% or better. Most
paints off the shelf won>t reach that level of reflectivity
If your lamp surface is originally metallized and degraded
significantly then painting it may restore some function, but will not
return it to original condition. If it is just flaking in a few
spots, you might be better off just leaving it alone as paint will
drop the light output significantly compared to the original. If it
was originally painted and is flaking, then painting it might be
somewhat helpful.
One question, though, how do you plan to get the lens off to do the
repair? If it is a late nineties lamp, the glue may be an epoxy,
which will make it difficult (if not impossible) to get the lens off
and reassemble after you open the lamp, or the lens may be welded on
which will make it difficult to get off and put back togeteher. The
big problem would be making sure you have the lens sealed after your
repair so that you don>t get water in the lamps and ruin any repair
you did do on the reflector or burn out bulbs at a faster pace because
of the water.
Also might want to make sure any paint you do use can withstand fairly
high temperatures without outgassing. The bulbs can put out a lot of
heat in that small space and you wouldn>t want to have your lamp fog
up from outgassing of the paint.
[/quote]
This is all very good information; thank you. The lamp surface looks
to be painted as it is not nearly as it is much duller than a
headlamp. I took some pictures of the damage to give a better idea:
Picture 1 - http://tinypic.com/view.php?pic=2j4d10l&s=4
Picture 2 - http://tinypic.com/view.php?pic=jkxa4n&s=4
This was with a stock wattage bulb and there was no water in the tail
lamps during my ownership (purchased the car used two years ago).
To remove the lens from the tail lamp, I plan on heating it up in the
oven briefly and then separating the two once the sealant becomes weak
enough. The process seems to work well enough for the people adding
ccfl tubes in their headlamps for pseudo-BMW "angel eyes." I believe
RTV sealant should be sufficient to seal the halves back together.
It is discouraging that an OEM tail lamp would deteroriate after so
few years. How does Stanley, the manufacturer of the lamp, generally
compare to other manufacturers such as Hella and Valeo?
It looks like I>ll go with Eastwood>s chrome galvanized aerosol as it
can withstand temperatures of up to 300 degrees F.
As an aside, is the reason why we see much less opaque tail lamps
lenses today because of the switch from painted to vacuum metallized
reflectors? One example that comes to mind is the difference between
the tail lamps between a 1996-1998 Honda Civic sedan and a 1999-2000.
Pictures for reference:
96-98: http://tinypic.com/view.php?pic=qx2s5f&s=4
99-00: http://tinypic.com/view.php?pic=i3didx&s=4
In any case, thanks again for the help.
-- |
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