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Author Topic: How to paint / conceal a ground strap?  (Read 2806 times)
W2RWJ
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Posts: 189




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« on: August 19, 2012, 08:38:29 AM »

I have a site that is installing a grounding trapeze* in a "doghouse" or very small dormer in the attic.   Feedlines are all 1/2 heliax (except for the OTA television which is RG-11)

The grounding straps will exit the attic through the underside of the eave, and run down the side of the building to the stakes and ring grounds.

The question is how do you hide or camouflage a shiny new ground strap from folks who steal such things?  I can't get the building paint to stick to copper, even after scuffing and solvent washing

*Link to product:  http://www.connectitwireless.net/grounding-products/arrestor-trapeze-buss/atk-u/
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KCJ9091
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« Reply #1 on: August 19, 2012, 12:57:23 PM »

Put it inside a pvc pipe and print the pvc to match.
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K3VAT
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« Reply #2 on: August 19, 2012, 01:13:14 PM »

I have a site that is installing a grounding trapeze* in a "doghouse" or very small dormer in the attic.   Feedlines are all 1/2 heliax (except for the OTA television which is RG-11)
The grounding straps will exit the attic through the underside of the eave, and run down the side of the building to the stakes and ring grounds.
...

This sounds like a multiple VHF/UHF antenna arrangement.  How many antennas and are they on the outside or inside of the dormer?  And where are you planning to mount the grounding assembly?

I've seen these trapeze assemblies used, but at the entry point which is OUTside the house (communications building), often close to the utility service ground where they are required to be physically connected.

Rich, K3VAT
« Last Edit: August 19, 2012, 01:30:15 PM by K3VAT » Logged
K1CJS
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Posts: 6045




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« Reply #3 on: August 20, 2012, 04:16:35 AM »

Yup.  You'll have a hard time getting paint to stick to copper, so how about some plain shelf covering contact plastic?  Available in almost any color, you can get something close to the color of the house paint, and simply lay the copper strap onto a strip of that plastic, folding the plastic over to cover it.

That stuff may also keep the strip from corroding too much as well.
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W2RWJ
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« Reply #4 on: August 20, 2012, 04:54:57 AM »

This sounds like a multiple VHF/UHF antenna arrangement.  How many antennas and are they on the outside or inside of the dormer?  And where are you planning to mount the grounding assembly?

The grounding trapeze will be mounted inside the dormer, along with the Alpha-Delta suppressors.    The cable jackets will be grounded on the outside of the dormer to s seperate bar, with it's own lead tied to the same grounding point.

The site is installing a ring ground, so the straps will literally run straight down the side of the building into the soil and be either exothermic welded to the rings (looking for the mold for that) or bolted with a bronze clamp.
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WB6BYU
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« Reply #5 on: August 20, 2012, 09:06:56 AM »

I'd look for some sort of metal primer that would stick to the copper, then put the
exterior paint over that.

Or run it down a length of plastic downspout.

(In fact, you could cut a long flat section out of a vinyl downspout or rain gutter
and tack it over the copper if you want it more flush to the wall.)
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W8JI
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« Reply #6 on: August 20, 2012, 12:41:15 PM »

I have a site that is installing a grounding trapeze* in a "doghouse" or very small dormer in the attic.   Feedlines are all 1/2 heliax (except for the OTA television which is RG-11)

The grounding straps will exit the attic through the underside of the eave, and run down the side of the building to the stakes and ring grounds.

The question is how do you hide or camouflage a shiny new ground strap from folks who steal such things?  I can't get the building paint to stick to copper, even after scuffing and solvent washing

*Link to product:  http://www.connectitwireless.net/grounding-products/arrestor-trapeze-buss/atk-u/

Are you sure you are installing a good system? Proper grounding would require a short low-impedance bond to the power mains ground point.

That aside, I have no problem painting copper with house paint when the copper is oxidized. It sounds to me like you are doing the opposite of what makes the paint stick. The last thing to do for painting would be shine it up.

If I didn't want to wait for nature, I would find some sort of etchant to wash the copper with. Just like aluminum, coper and brass needs a rough oxide layer so paint adheres. I paint the copper flashing on the side of my barn with normal old latex. 

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AA4HA
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« Reply #7 on: August 22, 2012, 12:28:52 PM »

What works too is to get a solder pot and tin the entire strap where it is visible so the thieves do not see shiny copper

Paint will stick to tin/lead.

Another trick is if you have ever worked with that plastic "tool dip" plastic coating. I have put that in a small bucket, diluted it with a compatible solvent and dip the copper into it. The copper then is coated with a very thin layer of plastic. You can get that in different colors.
« Last Edit: August 22, 2012, 12:31:52 PM by AA4HA » Logged

Ms. Tisha Hayes, AA4HA
Lookout Mountain, Alabama
LA9XSA
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Posts: 376




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« Reply #8 on: August 25, 2012, 01:27:54 AM »

Remember that lightning and other RF current likes to travel on the skin of the conductor, so if you coat it with something it should be as low impedance as the copper. Putting it inside PVC pipe or PVC conduit painted to match the house/down spouts sounds like the best idea; if you use metal pipe/conduit it has to be electrically bonded to the strap at the top and bottom.
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W8JI
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« Reply #9 on: August 25, 2012, 04:11:47 AM »

Remember that lightning and other RF current likes to travel on the skin of the conductor, so if you coat it with something it should be as low impedance as the copper. Putting it inside PVC pipe or PVC conduit painted to match the house/down spouts sounds like the best idea; if you use metal pipe/conduit it has to be electrically bonded to the strap at the top and bottom.

Actually the coating should probably be an insulator or a reasonably good conductor. A thin tin coating won't change radio frequency resistivity all that much, neither will paint. The copper oxide does not change it much either, and neither does normal thin silver plating.

Skin depth is pretty deep at the frequencies of concern.

73 Tom
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KB4QAA
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« Reply #10 on: August 25, 2012, 08:40:12 PM »

http://www.rustoleum.com/CBGResourceCenter.asp?sn=ms2&msdstyp=PROCBG&msdsprc=397

Rustoleum Acid Etch Primer for bare metals
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W8JI
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« Reply #11 on: August 26, 2012, 02:52:35 PM »


There ya go. If you don't want to age it a month in acid rain, just buy some of that.

I wondered about rubbing it with Coke or Pepsi, or my wife's lasagna.
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