Actually, painting your anodic material is the LAST thing you want to do if
you have a big galvanic potential between 2 metals and an electrolyte (i.e.
galvanic cell). When you have a coating defect, your anode is MUCH smaller
and corrodes much faster, leaving what's under inadequately protected.
regards,
Dave N3AC
On Mon, Aug 9, 2021 at 8:59 AM Gary <gary_mayfield@hotmail.com> wrote:
> Neat Topic -- I wonder if anyone has looked at active cathodic protection,
> like used in the pipeline business?
>
> 73,
> Joe kk0sd
>
> -----Original Message-----
> From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of Máximo
> EA1DDO_HK1H
> Sent: Monday, August 9, 2021 1:17 AM
> To: Richard Smith <n6kt1@sbcglobal.net>; 'towertalk@contesting.com' <
> towertalk@contesting.com>
> Subject: Re: [TowerTalk] Experience with Sacrificial Zinc?
>
> There are different quality grades on hot dipped galvanizing. Those
> quality grades are basically the size of the zinc layer.
> For hard enviroment areas, galvanizing is thicker.
>
> For extra protection, a special paint coat is needed, on the top of the
> hot dip galvanizing.
> It is two or three layers of two-componenets paint, called aliphatic
> enamel.
>
> So, if you hot dip galvanize a tower, with thick zinc layer, industrial
> grade, then you apply two or three layer of aliphatic enamel paint, you
> will get top professional protection, lasting many years.
>
> 73, Maximo EA1DDO
>
> ________________________________
> De: TowerTalk <towertalk-bounces@contesting.com> en nombre de Richard
> Smith <n6kt1@sbcglobal.net>
> Enviado: lunes, 9 de agosto de 2021 2:51
> Para: 'towertalk@contesting.com' <towertalk@contesting.com>
> Asunto: Re: [TowerTalk] Experience with Sacrificial Zinc?
>
> Hi Grant,
> Thanks for your response. At our station in PJ4, the Hot Dipped
> Galvanizing is holding up well, but some parts are Electro-Galvanized and
> are already corroding. Part of the problem is erosion from trade winds,
> which seems to wear down the Electro-Galvanizing, which then exposes the
> base metal to a corrosive environment. Specifically, the Orion rotor drive
> plates and mast clamps seem susceptible to the erosion and the subsequent
> corrosion.
> I was wondering if attaching a piece of zinc metal directly to those
> specific parts would slow down the corrosion. The team is looking at
> changes to help this situation in the future, but I'm also trying to find a
> quicker solution for the parts that are already installed.
> The black tar coating followed by PVC tape sounds like a very good
> solution for buried parts.
> 73, Rich, N6KT
> On Sunday, August 8, 2021, 05:11:51 PM PDT, Grant Saviers <
> grants2@pacbell.net> wrote:
>
> The MIL-HDBK-419A talks a little about this topic. Adding Zn electrodes
> to a galvanized tower creates a parallel circuit, not clear which will go
> first IMO. Impressed voltage systems are probably a better option.
> google it.
>
> I black tar coated my galvanized guy anchor rods and then wrapped them
> with 20mil 2" wide PVC tape for abrasion resistance to 2 feet above grade,
> same as done for black iron gas pipes that are buried. Should last longer
> than me.
>
> Grant KZ1W
>
> On 8/8/2021 16:30, Richard Smith wrote:
> > Hi Tower Talkers,
> > It seems that sacrificial zinc is commonly used in boating to stop
> corrosion. The sacrificial zinc corrodes and "saves" the metal to which it
> is attached.
> > Does anyone in TowerTalk land have experience with using sacrificial
> zinc with towers and/or antennas?
> > 73, Rich, N6KT
> > _______________________________________________
> >
> >
> >
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> >
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