Re: Instrument Gauges Fogged Up
Some Fogging is normal, or at least not unusual.
I have new Faria gauges.
They definitely have vent holes in the back and are not sealed hermetically.
However they are sealed mechanically.
The front bezels are seam rolled to the cases; There is no way short of destruction to open them up.
Warming them up with the lights will speed up the defogging. A hair blower would be even faster.
Your Teleflex gauges are likely similar.
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From Faria;
Instrument Fogging:
Most marine instruments have small vents in their cases to allow a way out for moisture that finds its way in. It is possible for moist air to be drawn into the vents when the air inside the gauge cools down after the instrument is turned off. The morning sun can draw this moisture up against the lens, causing fogging. Turning on the instrument with the instrument light "on" will speed up moisture removal. Fogging is not abnormal, nor will it harm your instrument, which is built to withstand the harsh marine environment.
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From Teleflex;
Fogging of Instruments
Until the introduction of Teleflex fog resistant gauges, all commercially available gauges were subject to fogging. Teleflex Pro Series gauges include a coating on the inside of the lens that prevents condensation from forming. Depending on the outside temperature, humidity, air flow to the gauge, and gauge placement in a panel, other gauges can fog. Usually the gauge fogs when the inside and outside temperatures of a gauge change drastically. Such a change occurs when the gauge is first turned on. The meter movement of the gauge heats the moist air inside while air outside the glass remains cooler, and the gauge fogs.
If the gauge is mounted vertically in a panel, the fog rises to the top of the gauge with little fog on the glass. If the gauge were horizontal, the fog would rise to the glass, probably covering it entirely. If the gauge were tilted back 45 degrees, only about half the glass would be fogged.
Fogging is dissipated when the heat inside the gauge causes an air convection to begin moving from the back of the gauge through its interior.
This constant flow of air should slowly clear the glass. Turning on the gauge light (causing more heat) helps in clearing the glass. If the glass does not clear, remove the socket and bulb and let a lot of air into the gauge. This step may be necessary in high humidity conditions. If air flow behind the gauge is poor (area sealed off), it may be more difficult to dissipate the fog. Replacing the fogging gauge is a last resort. It is not always an effective remedy, unless the replacement is a Pro Series unit.
). Also, the gauges reflect off the windshield at nite and appear as another set of gauges right in my line of sight, not the safest thing for boating at nite! I find myself covering the gauges up with a towel. Another project is to install a dimmer switch for the instrument lights as well, and maybe look into making some type of shade cover for the dash overhanging the gauges to totally block out the glare. Will keep ya's posted to how it turns out....and as always, thanks for the input!
