| It may not be a simple rain issue. I've noticed many Lancair fibreglass components don't get covered with the proper anti-static primer as required for commercial and MIL-SPEC paint systems. Wicks help but they won't discharge the 100kV from a Legacy wingtip because there is no path from the paint surface to the static wick. WIth that kind of voltage built up in precipitation, radios will disappear and small pin holes will be blasted in the paint as little lightning strikes exit the paint surface. In the days of ADF, the needle would spin aimlessly and today I know my Legacy radios die in dry snow. You can actually see sparks at night in snow or rain if you are in this situation.
I don't know the WLS system but many of you are using PPG paints and they have an anti-static system for composite aircraft. This is one example:
I'd really be interested in anyone who has used the 528X310 anti-static primer used in this system because I want to re-do my Legacy fibreglass wingtips especially since that's where one or more antennae are located.
Who does this properly? I've talked to expert paint shops all over Canada and the US and the typical response is that they've never had a problem with any paint job. It was only when I spoke to Field Aviation in Toronto that I learned about the military and commercial requirements for static protection and the messy black primers that were required to be used. After that, I took my Cessna back to the paint shop and when they applied the proper coatings, all those problems disappeared. Today, you have white, grey and other primer colors to use for static protection so that's not a problem.
If you're doing paint, it would pay to look at this issue. It makes no sense to get into precipitation or moisture and degrade the systems that might be needed to get out of weather. IFR isn't the reason to use such a paint system. The use of non-conductive composite components is the reason it is required.
Does anyone have experience with a paint shop that knows this stuff? I would be interested to hear how other owners have or have not dealt with this issue.
BTW, I have a certified aircraft with 17 years of original paint with 2000+ hours and used in hard IFR, snow, rain at 285KTAS. Beyond a few stone chips there is no erosion or wear except for a few pinholes in the composite wingtips where they apparently forgot to use the correct primer. So, aerospace paints can definitely hold up to continuous rain and IFR conditions without concern for years.
Paul Spruce Creek FL Legacy RG On 2012-03-19, at 6:17 AM, Charles Brown wrote: OK, the guys who already know this can sit back and chuckle, the rest of you, here's a bulletin on flying IFR in primer. I gather that WLS primer is not as hard as paint and about a half hour in moderate rain at 210ktas was enough to visibly erode small areas of all the leading edges. I think all that really happened was that defects in the underlying layers, which had been filled by WLS, were revealed. At any rate, there were numerous small areas (largest: 1/4" X 1/4"; most areas smaller) where pinholes, underlying BID mesh, and occasional air bubbles in micro were revealed. Recommendation: fly with a harder coating than WLS or avoid rain. The WLS held up just fine in ordinary flying for 100 hours. I've scheduled paint as soon as I can get into the shop, in the meantime I'm repairing the leading edges and spraying the repairs with K36 primer which the paint shop recommended (and I can get a quart for $80 rather than paying $300 for a gallon of WLS). Then, until painting, I'll cover the leading edges with leading edge tape. Question for you IFR guys with APA (Already-Painted Airplanes): What's your experience with rain and paint? Charley Brown Legacy #299 100 hours -- For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html
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