It is hard to believe the misting cannot be cured, I understand all the excuses about temperature differentials - yawn - but in all the years of flying in Tiger Moths all year round I never once experienced this phenomena, or in any other light aircraft for that matter.
It'll be interesting if Kerry can add some input on this one about older aircraft too.
I’m pretty sure by the 1930’s Smiths Aero instruments will have been hermetically sealed
So another case like the fastenings of Morgan building down to a price and not improving the quality that should be expected at the current price ranges.
I might be wrong but I don’t think it’s anything to do with Morgan
I’ve been on what are now branded as Smiths car gauges website and downloaded the catalogue and I can’t see any reference to them being vacuum sealed. The glasses and bezels can be replaced and the gauge can be got into in the back to change the lamps so I don’t think the ones that go on a Mog are fully sealed to the point where no moisture in the air can get into the unit
Some of the older VDO instruments might have been better sealed but they still had a plastic lamp holder that could be pulled out of the back quite easily
On my last Mog it was only the small dials that fogged up - the large VDO dials were fog free
