Author Topic: Instrument fogging cured  (Read 4897 times)

awolff280sl

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Instrument fogging cured
« on: December 17, 2013, 02:55:44 »
in Florida, I had been dealing with speedometer fogging for years.
It appears to have been cured by the use of LEDs.
Theory is that the incandescent heat caused the fogging.
Andy   Sarasota, FL
'69 280SL 4speed
'06 Mitsubishi Evo

mdsalemi

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Re: Instrument fogging cured
« Reply #1 on: December 17, 2013, 13:04:41 »
Brilliant!

At first, I thought this to be suspect. After all, one usually uses heat to cure some kind of fogging; think your defroster blowing hot air, or similar.
The more I thought about it, it makes sense: when the lights are illuminated, the internal temperature of the instrument goes up. Higher temps mean the internal atmosphere can hold more moisture. More moisture? Fogging.
LEDS operate at much cooler temps…less moisture in the atmosphere.

Brilliant, Andy!
Michael Salemi
Davidson, North Carolina (Charlotte Area) USA
1969 280SL (USA-Spec)
Signal Red 568G w/Black Leather (Restored)
2023 Ford Maverick Lariat Hybrid "Area 51"
2023 Ford Escape Hybrid
2024 Ford Mustang Mach Ex PEV

cbenz1

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Re: Instrument fogging cured
« Reply #2 on: December 17, 2013, 17:18:39 »
WOW - that is an amazing find!!!!! You are famous now for solving a long standing issue.  So where do we get those?

66andBlue

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Re: Instrument fogging cured
« Reply #3 on: December 17, 2013, 17:26:39 »
Check this topic for suppliers and more info: http://www.sl113.org/forums/index.php?topic=19084.
Alfred
1964 230SL manual 4-speed 568H signal red
1966 230SL automatic 334G light blue (sold)
1968 280SL automatic (now 904G midnight blue)

awolff280sl

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Re: Instrument fogging cured
« Reply #4 on: December 17, 2013, 23:33:26 »
Not brilliant, but cool. I only figured it might cure the fogging while waiting for the LEDs to arrive, which I thought to use for the purpose of more light, not to eliminate the fogging.
Additionally, the speedo and tach were not quite bright enough with the LEDs, but I had the inside of the rubber casing sprayed with gloss white paint, and that did the trick.
Also, one of the light sockets on the tach would not take a 4-LED too easily even with some minor modification, so I used a 1-LED which is slightly smaller and fits well.
I see no difference in brightness from the speedo which is using 2 4-LEDs.
Andy   Sarasota, FL
'69 280SL 4speed
'06 Mitsubishi Evo

garymand

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Re: Instrument fogging cured
« Reply #5 on: December 17, 2013, 23:50:33 »
Good update, I went to the LEDs too,  I really like the white color and just got the smaller bulbs for the speedo and clock.  Great tip in spraying the housing.  I had to put two for the 4s to my grinder to reduce the diameter with no ill effects to the LED.  I had to refuse my clock, clean, re-oil and calibrate the clock.  I've done this once before, but it is still taking me 6 or 8 adjustments over at least 4 days each to get the clock back on time. 
Gary
Early 250SL German version owned since 71, C320, R350, 89 Porsche 944 Turbo S

zoegrlh

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Re: Instrument fogging cured
« Reply #6 on: December 18, 2013, 03:24:25 »
LEDs work very well in the tail and brake lights too.  They burn brighter and can be seen better at night.  This is a real safety item.  Anytime you can see the car stopping by having brighter lights at night, the less change of a rear end crash.  My insurance company should give me a discount on premiums..
Bob
Robert Hyatt
Williamsburg, VA.

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awolff280sl

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Re: Instrument fogging cured
« Reply #7 on: December 18, 2013, 03:41:09 »
hi Bob,
Do you have the specs for those?
Andy   Sarasota, FL
'69 280SL 4speed
'06 Mitsubishi Evo