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Paint GPS antenna?

cajunwings

Well Known Member
Looking for any feedback. GTN 650 and plan to mount the Garmin GPS GA-35 antenna on the glare shield of my RV9 slider. Label says Do Not Paint, but it can’t stay white in this location. Anybody painted their antenna flat black and have you noticed any reception issues due to the paint? Can’t be any worse than the engine compartment antennas under a painted cowl. Thanks.

Don Broussard
RV9 Rebuild in Progress
57 Pacer
 
You can do a test by painting a shoe box with the color of your choice. Cover the GPS antenna with the shoebox and see if your GPS reception is affected or not. It not, then it probably will not give you any problem. Like these warnings, it's more about CYA for the certificate airplane
 
The 650 antenna on the glare shield is problematic - make sure you add length to the feed line to meet the minimum length. Verify it works while you transmit on the 650 or your Comm #2 by monitoring the GPS satellite signal strength page.

Don’t paint. Just cover the antenna with a piece of dark gray cloth or so. Tuck the cloth edges under the puck when you attach. I’ve done this for years.

Carl
 
Why can't it be white? Typically the issue with light reflection is the sheen, not the color. For my two black GPS antennae on the glareshield, I sanded them with 400 grit and knocked off all of the sheen and are now flat. Absolutely 0 glare. Did the same with the light grey support column on the 10, same result. It is true that black absorbs and white reflects, but that is mostly relevant in the UV spectrum. glare is mostly about reflected visible light and that is all about sheen, not color

The glareshield on my 10 is black, but eggshell and not flat. Get plenty of glare.

Larry
 
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The GPS signal is so weak you have to give it all the help you can to reach the business part of the antenna. Painting runs the risk of degrading the GPS performance, possibly a lot. Covering with cloth sounds a much better idea!
 
A Lycra fabric works well for preventing glare from the GPS antenna, Lycra is very elastic and has many colors available.
 
I'm not sure, but I think the reason why a lot of blade transponder and GPS antennas shouldn't be painted is because almost all paints contain titanium dioxide and some form of carbon, either of which can shield or attenuate the signal. So, if you can determine that the paint has neither of those compounds ( or other metallic salts) you should be good to go.
The suggestions of using a conformal fabric covering is a great idea.
 
Paint GPS Antenna?

I have painted 3 or 4 of them over the last 15 years. No problems with GPS reception. My guess is that they don't want their logo covered.
 
The Garmin GPS antenna that was originally for my 430W, now used for my IFD440, says "Do Not Paint", presumably because the paint affects signal? But it's mounted under the cowl, underneath fiberglass and paint between it and satellites and works just fine. Hard for me to reconcile the problem with mounting it externally and painting it. The GPS antenna for my AFS5400 is flat black and is mounted on the glareshield, as is the GPS antenna for my G5.
 

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Use Plastic Dip it's a rubber type coating in a spay can. Apply 6 coats and it gives you any problem you can peel it off, less coats is hard to peel.
 
Simple sock

Like Don, I just fabricated a simple sock for the antenna out of black stretchy material. A few quick stitches and all is hidden under the antenna. Sits nice and flush. Just enough tension to fit tightly but not so much the white shines through. I have 2 like that now.
 
I coat my 430W GPS antenna with a black wide tip magic marker once a year. It is mounted on the glare shield and has worked fine for over 15 years!
 
If you use a flat black latex paint, it will not have any of the metallic components in it that will inhibit the reception.
 
Test first...

Make sure the paint doesn't contain radio frequency opaque/absorbent materials like carbon (graphite, graphene, etc.), metal-flake (alumina bad, mica good...).

The easiest thing to do is mask the antenna with painters tape, plastic sheeting, , something removable. Shoot your favorite paint and then test the GPS reception -- before & after.
 
Like Don, I just fabricated a simple sock for the antenna out of black stretchy material. A few quick stitches and all is hidden under the antenna. Sits nice and flush. Just enough tension to fit tightly but not so much the white shines through. I have 2 like that now.

Like these headset covers...
11-12191a.jpg
 
This issue with painting a GPS antenna or any other antenna is static dissipation in rain and other precipitation like dry snow. The processes used by manufacturers allow built-up charges to migrate through the paint to a ground plane. When you use non-mil-spec processes that do not allow static dissipation then the antenna can become unusable as static charges build. As the charges build they are dissipated as sparks to other ground points and cause noise in the reception. Static would probably only apply for exterior antenna placement. If the antenna is inside the airframe then it would not see rain or snow and you can do what you want without effect.

You can always refer to the antenna manufacturers to request advice on paint or repaint if you want to update or change the coating. I've spoken to a number of firms like Comant who provide free tech support for paint issues.
 
I worked for Comant in the day. Engineers said to never paint. They are built detuned and when painted at the factory they come into spec.
 
Have a friend that has 2 pucks on his glareshild that are painted black. I asked him about it and he said you can as long as there was no metal in the paint.

When I asked, I was thinking more about heat if painted black.

It does make me wonder why Garmin doesn’t offer a black puck.
 
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Things that make you go hmmmm……
Stein, as usual, answers the question.
 

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