gauge faces - glass or plastic ?

[Johnster]

Hello all,
  I went for a night ride on the newly-resurrected 1979 R65 and I found that the speedo face was very dirtyy (except near the perimeter???)

Wiping the outside didnt do anything, so I think I need to take it apart.

I've looked at a few writeups (I still can't get the wiki here to work but none of them say what the 'glass' is made out of (glass or lexan ?)- this will make a big difference in the cleaning fluid used.

any ideas here ?  

1979 R65, Build Date Dec1978, 30k miles, gold paint/brown seat.

-John

[montmil]

You will have to very carefully pry the metal trim ring off the speedo to remove the "glass" for cleaning. If the speedometer is still unmarred, it may be less noticeable after re-crimping the metal ring if you are still utilizing the R65s instrument pod.

If unsure as to the composition of the "glass", start cleaning with water or Windex. Harsh chemicals could ruin the picture window and new speedos ain't cheap.

[k_enn]

I am not sure if it is glass or plastic.  If the surface is anything like old headlights that get "hazy" with age, I would try cleaning it like you would headlights.  

For headlights (even plastic headlight covers) I have had good experience with toothpaste or with rubbing compound designed for clear-coat paints.  (Don't use regular rubbing compound, it may be too strong).  Both toothpaste and clear-coat compound are pretty mild abrasives that should remove surface contamination with the application of a little "elbow grease."  

k_enn

[Barry]

none of them say what the 'glass' is made out of (glass or lexan ?

I'm no expert but I believe they are glass, not ordinary glass but an anti glare type.

Wirespokes will know for sure.

[nhmaf]

Also, be aware that in the cool evenings/days, they can have a tendency to "fog" on the inside

[Johnster]

It was a cool(er) night (60F or so?)  But the tach wasnt dirty at all, and I've never seen the faces backlit at night before.
  the speedo was effecitively unreadable.  blah.

-John

[Bob_Roller]

The OEM bulbs for backlighting are not the greatest to start with, may want to remove them and see if the bulb glass has turned black/silver on the inside .

A few members here have upgraded to LED replacements .

[nhmaf]

The LEDs are MUCH brighter - but as a side effect of their cool operation - they don't produce any significant heat to dry out the instruments on the inside.  The 3W bulbs weren't really effective at that either, but BMW thought that they would be.

[jg928s4]

my tack was not clear.  It is a plastic lens.  I disassembled and used a plastic polish and buffed them clear.  Be carefull not to heat them up or they can melt and never look good.

[tvrla]

The gauges came stock with anti glare glass. It's etched on one side - the outside surface of the face.

You might try dribbling some alcohol into the gauge and swirl it around the inside of the glass. It's possible that will carry away the grime. I wouldn't try anything stronger.

My gauges used to fog up really bad, but LEDs solved that problem. I believe the condensation was caused by the heat from the incandescents. Just like mufflers, when cooling down they draw moisture from the air. The LEDs run cool so don't have that problem.

They're also much brighter - they give off a bluish white light that's pretty cool.