Painted several "glass fiber" antennas (antennae) to stop shedding the glass
fiber. Observed no effect on the electric parameters.
Keep in mind that the antennas has a conducting rod inside that serves the
purpose of being the actual antenna.
I have never tried to paint an insulator and would expect some trouble with
current creep there if the paint is not the "right" type or conductive in any
sense.
Best seventy-three (I'm an old ham) de,
Hans - N2JFS
On 1/4/2015 1:28 PM, Joe Ciarcia wrote:
> We painted a 4 ele stepp-IR with marine topside paint purchased from
> Lowe's. It was green and probably
> made by Pettit don't remember. Anyway a check with the manufacturer
> confirmed no conductive content.
> No effect on the antenna tuning was apparent (this was an older antenna).
> Paint is holding up well.
> 73, Joe K1JC
>
> On Sun, Jan 4, 2015 at 12:38 PM, Howard W6HDG <W6HDG@arrl.net> wrote:
>
>> Happy New Year.
>>
>> I asked this question on the Steppir Yahoo Group but didn't get an
>> adequate answer. I'm probably being way too compulsive but I'll ask it
>> here since there are so many experienced members.
>>
>> I'm going to be preemptively painting my new DB18 with the marine topside
>> paint recommended by several Steppir forum members. This sounds smart
>> since the San Diego sun can be brutal to fiberglass and plastics.
>>
>> I was concerned because the light blue "Blue Ice" Pettit Easypoxy Topside
>> Paint color I purchased contains 35% titanium dioxide and 10% aluminum
>> dioxide. Both the Pettit and Interlux brands of marine top coat in any
>> of the light colors seem to have quite a bit of the Ti02. Even Medium grays
>> have Ti02 as well as carbon black. Browns have iron oxide. In fact the only
>> marine paint which doesn't have any metallic sounding ingredient is Pettit
>> 3350 Easypoxy Kelly Green Topside Paint. Could that be why Steppir chose
>> the green color for their fiberglass??
>>
>> So here is where I am at. I wonder if my 4 tests with "Blue Ice" marine
>> paint were adequate to insure minimal interaction from the paint? Your
>> ideas welcomed.....
>>
>> Test 1) I painted 6 inches of an 8 inch piece of 1" white PVC, allowed it
>> to dry for a day and placed it in the microwave along with a small cup of
>> water. I waited until the water boiled. The coated PVC remained cool and
>> was the same temp as the uncoated area.
>>
>> Test 2) I coated a 30 inch piece of 1" PVC and allowed it to dry. I used
>> a dual band VHF/UHF magnetic whip on my car and measured the signal
>> strength of various distant repeaters. I then placed a plain piece of 30"
>> PVC over the entire whip and repeated the tests. Signal strengths were all
>> pretty much the same with a couple of weak repeaters showing up to one S
>> unit less than the bare tests. I then tested with the coated PVC. There
>> was no difference in any signal levels between the uncoated and coated PVC.
>>
>> Test 3) I put two copper probes into water and measured resistance. It
>> measured between .3 and .5 megaohm. I then put the two copper probes
>> directly into the liquid paint and got zero resistance on all meter scales.
>>
>> Test 4) I glued three strips of copper on an 8 inch piece of 1" white
>> PVC. The strips had a separation of 1/4 inch. Each strip had a wire lead
>> soldered to it. I then painted over the entire tube and let it dry for a
>> day. I could get no DC resistance measured between probes. I then placed
>> 117VAC across the two outer probes. I tried to measure any leakage to the
>> center probe and was not able to measure any voltage.
>>
>> So pretty compulsive, huh? Have I proven anything here or just created a
>> false sense of security? I figure that paint is much less reactive than
>> water. We know you can get electrocuted in a bathtub and that rainy
>> weather changes our SWR. I figure that marine paint, even if it has
>> metallic sounding compounds in it (short of metallic flakes like some auto
>> paints!) is OK for the Steppir.
>>
>> 73, Howard W6HDG _______________________________________________
>>
>>
>>
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