[Elecraft] K2 near the sea: leave on or not?

Wed Apr 18 10:49:29 EDT 2007

Conformal coating is actually meant to solve a completely different  
problem. Imagine an environment that regularly goes from high heat/ 
high humidity to very cold/dry conditions in just a few minutes. When  
that happens, condensation is sure to happen. Conformal coating takes  
care of this situation very nicely.

Oh, this situation happens thousands of times every day - it is the  
environment for aircraft avionics...

To the original poster: Don't worry about it. It really isn't a  
problem where you live. If you worry about this, you also need to  
worry about the sand particles from the Sahara that are regularly  
carried into South Florida on the tradewinds (and also effect  
hurricane development).

On Apr 18, 2007, at 4:54 AM, <d.cutter at ntlworld.com>  
<d.cutter at ntlworld.com> wrote:

> In the old days we used to call it tropicallising, now it's called  
> conformal coating and refers to a material either sprayed, painted  
> or dipped onto the electrical parts.  Conformal coating for  
> military is very expensive and time consuming involving inspection  
> with a uv lamp to pick up the uv die in the material, to descover  
> imperfections and can be up to 3 layes thick.
>
> If you don't keep you equipment in an air tight box, then leave it  
> switched on to slow down the deposition of salt products.  I think  
> this works by keeping the interior warmer and thus higher air  
> pressure to prevent the ingress from the surroundings.  Of course  
> when you switch off it cools and the pressure falls and drags in  
> the cooler contaminating air from the surroundings and that's when  
> the damage starts.  So, switch off and immediately put into an air  
> tight box.  It all sounds a bit excessive, but the other way is to  
> coat everything with bare metal with a suitable coating, like the  
> one mentioned from another reply.  The lacquer and and varnish  
> sprays that you hold 6" away are only partly effective because tall  
> components create shaddows and the spray doesn't get in properly.   
> They work on the solder side fairly well, but the cut off component  
> wires do not get a coating - it runs off.  Genuine conformal  
> coating comes expensive, is thick and does not run.  Last time I boug
>  ht some it was about £40 for 400mL (circa 1990) made by Dow  
> Corning but there are more types to choose from now.  If you spray,  
> use several layers and get right in between the components; let it  
> dry between sprays.  Take care that on some rf components you may  
> get a small shift in value upsetting your carefully trimmed filters  
> etc.
>
> David
> G3UNA
>>
>> From: Tom Zeltwanger <KG3V at ChesBayVA.com>
>> Date: 2007/04/17 Tue PM 03:34:29 BST
>> To: "Fred (FL)" <ncsailors at yahoo.com>
>> CC: elecraft at mailman.qth.net
>> Subject: Re: [Elecraft] K2 near the sea: leave on or not?
>>
>> I operate from the shores of the Chesapeake Bay in Virginia. The  
>> water there is
>> only moderately salty but corrosion is very rapid compared to my  
>> experience
>> with inland QTHs. I was wondering if this would be a problem for  
>> my equipment.
>> So far, no problem. I imagine anyone near the sea shores has this  
>> problem.
>>
>> 73,
>>
>> Tom KG3V
>>
>>
>>
>> Quoting "Fred (FL)" <ncsailors at yahoo.com>:
>>
>>> RUSTY Florida area?
>>>
>>> I'm surprised to hear about corrosive salty-air
>>> regions in Florida.  Just never heard of it?
>>> Our son lives on big island of Hawaii - near
>>> Hilo.  The salt water air type of corrosion, on
>>> things like bicycles, etc. - is notorious in Hawaii.
>>> Things there - not protected, don't last so long.
>>>
>>> Islands of Hawaii - are in the trade winds region
>>> of the Pacific - and I guess get their daily dose
>>> of salty air, naturally.  I'm not sure this is
>>> the case on either coast of Florida.  I'm probably
>>> wrong tho.  The big island, above city of Hilo -
>>> gets a daily dose of natural rain, like 2 pm
>>> every afternoon.  Perhaps the rain there, has
>>> some salinity.
>>>
>>> For some reason I've not heard this about Florida.
>>>
>>> We live 8 miles from the Gulf Coast of mid-western
>>> Florida.  I can't say I see anything around our home,
>>> or in my garage, etc. - that has any appearance
>>> of salt corrosion.  Cars look exceptional - easy
>>> to keep clean.  No visible corrosion on anything
>>> we have?  No rust on tools, etc.
>>>
>>> I wonder what the salinity is of the Florida
>>> Atlantic ocean, vs the Hawaiian Pacific ocean
>>> and the trade winds?
>>>
>>> Fred,
>>> N3CSY
>>>
>>>
>>>
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>>
>>
>>
>>
>>
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- Jack Brindle, W6FB
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