[R-390] R-390 Digest, Vol 107, Issue 23

Thu Mar 21 17:39:33 EDT 2013

For my 6 cents, worth, "inflation,"  I have never liked those lacquer/paint/oil sticks. I have tried a number of different kinds and did not like the results.
I have done many panels, over 65, and here is the short version of my process. The first thing is the panel needs to be painted with a good quality paint; I use Sherwin Williams enamel. 

Then ((VERY IMPORTANT)) the paint must be completely cured before doing the lettering. Either baked at 140F for 4 hours let it cool and baked for another 4 hours at 130F or sun cured for a few weeks. If it's left inside to cure I would not proceed for at least a month. Shortcuts with my process will yield a mess that will require re-stripping the panel; been there and done that multiple times.

I use acrylic white paint and dob it on heavy with a brush like the disposable Harbor Freight cheapies!  Then use a small plastic Bondo blade, from the auto stores covered with a water dampened shop towel. Have plenty ready to get rid of most of the excess white paint. This is the messy part, so, plan on having some clean up water, lots of shop towels and a trash can/basket handy. I also use disposable gloves as well.

 The panel will have white smear everywhere but don't fret, it's going to get worse.. After I make a pass all around the panel, I do it once more, yes a second pass, with the same process. Now the panels really looks bad,,,,really really BAD!. 

Wait about 10 minutes and in a well ventilated location, outside is good, and with chemical resistant gloves on, wet a folded shop towel with Acetone and start wiping. I fold the towel in half 4 times and wipe with the towel flat over the lettering wells with as little pressure as possible.You will need to keep folding the towel different ways to have a clean surface. As you wipe the smear away, you will see the clean bright lettering jump out at you. 

I have never seen an original panel look this good. I often see some lettering that never received paint or originally smeared lettering. Often the original paint looks like it was very thin and never lives up to what you can achieve with this process.

 I have played with all kinds of solvents but Acetone works best by far. NOTE..You do NOT want to breath acetone fumes, thus I prefer going out side for this. 

If the panel paint is not completely cured the acetone will take some of the top coat off too and make a big mess. If you have any doubts about using Acetone try this. Before you strip the panel, go outside and pour a cup of acetone on the panel, let it start evaporate and try to remove the paint. You will see just  grime/dirt and almost no paint at all.  I learned this when I was experimenting with stripping panels and wondered if Acetone would work, IT DID NOT!!.. 

If anyone cares, I have a 4 or 5 page document that I wrote up for complete panel restoration including, stripping, paint types, panel repairs, equipment I use, lettering and panel finishing. I wasted a lot of money and time developing a process I like that gives repeatable results. I can email or post it here it if there is interest. However, it will be a few weeks, since I am recovering from a back injury and don't want to go to that system at a different location now.

73,
Glenn WA4AOS
DSM Labs  (dot com)

-----Original Message-----
From: r-390-request <r-390-request at mailman.qth.net>
To: r-390 <r-390 at mailman.qth.net>
Sent: Thu, Mar 21, 2013 12:47 pm
Subject: R-390 Digest, Vol 107, Issue 23

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Today's Topics:

   1. Re: Engraved Panel (Raymond Cote)
   2. Re: Engraved Panel (rbethman)
   3. Re: GFCI issues (Bob Camp)
   4. Re: GFCI issues (rbethman)
   5. GFCI info (rbethman)

----------------------------------------------------------------------

Message: 1
Date: Wed, 20 Mar 2013 16:19:00 -0500
From: Raymond Cote <bluegrassdakine at hotmail.com>
To: rbethman <rbethman at comcast.net>
Cc: R-390-List <R-390 at mailman.qth.net>
Subject: Re: [R-390] Engraved Panel
Message-ID: <BAY403-EAS3967C3CF25D264479339A79A9EA0 at phx.gbl>
Content-Type: text/plain; charset="us-ascii"

Aren't those the same sticks avail from Antique electronics out of Arizona?  I 
seem to remember that coming up a couple years ago. Anyway congrats on getting 
panel ready for mounting. 
Ray 

On Mar 20, 2013, at 15:13, "rbethman" <rbethman at comcast.net> wrote:

> I have been fighting with refinishing an engraved panel for about 2 years.
> 
> I achieved success!
> 
> I went to a Craft Store, and picked up "Oil Pastel Sticks". (They are really 
$$$$ all of $1.99!)
> 
> After I rub the white one into the engraving, I can wipe the excess off around 
it with denatured alcohol!
> 
> Hurray!
> 
> I just got a decent power supply module.  Now I'm going to get this old thing 
back together and going!
> 
> Bob - N0DGN
> ______________________________________________________________
> R-390 mailing list
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> 
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> Please help support this email list: http://www.qsl.net/donate.html

------------------------------

Message: 2
Date: Wed, 20 Mar 2013 17:24:20 -0400
From: rbethman <rbethman at comcast.net>
To: R-390-List <R-390 at mailman.qth.net>
Subject: Re: [R-390] Engraved Panel
Message-ID: <514A2904.4050406 at comcast.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Ray,

I really don't know.  But these are a set of 12 different colors.

At the princely sum of $1.99 for the set, I figured I couldn't go too 
wrong.  I got them at an A. C. Moore Arts and Crafts store.

Yes - I'm inherently cheap!

However, I've got enough labor and capacitors plus resistors in this, it 
makes up for it!

I'm only interested in the white one.

Bob - N0DGN

On 3/20/2013 5:19 PM, Raymond Cote wrote:
> Aren't those the same sticks avail from Antique electronics out of Arizona?  I 
seem to remember that coming up a couple years ago. Anyway congrats on getting 
panel ready for mounting.
> Ray
>
>
>
> On Mar 20, 2013, at 15:13, "rbethman" <rbethman at comcast.net> wrote:
>
>> I have been fighting with refinishing an engraved panel for about 2 years.
>>
>> I achieved success!
>>
>> I went to a Craft Store, and picked up "Oil Pastel Sticks". (They are really 
$$$$ all of $1.99!)
>>
>> After I rub the white one into the engraving, I can wipe the excess off 
around it with denatured alcohol!
>>
>> Hurray!
>>
>> I just got a decent power supply module.  Now I'm going to get this old thing 
back together and going!
>>
>> Bob - N0DGN
>>

------------------------------

Message: 3
Date: Wed, 20 Mar 2013 20:22:50 -0400
From: Bob Camp <ham at kb8tq.com>
To: "r-390 at mailman.qth.net Group" <r-390 at mailman.qth.net>
Subject: Re: [R-390] GFCI issues
Message-ID: <C624E97B-0581-4145-A3DA-199910861624 at kb8tq.com>
Content-Type: text/plain; charset=us-ascii

Hi

Keep in mind that there is no way a two wire device can trip a working GFCI all 
by it's self. It simply can't generate an imbalance between the hot and the 
neutral. There's no place else for the current to go. In order for it to trip a 
GFCI, there *must* be a third path, generally to ground. Assuming you are 
holding the two wire device up in the air (and not underwater) the only place 
for the current to go is through you. It's not going through the air. If it's 
going through you, you *would* notice it.

Bob

On Mar 20, 2013, at 4:04 PM, rbethman <rbethman at comcast.net> wrote:

> I used Mr. Hacksaw.
> 
> I can now look at the circuit inside.
> 
> The Hot and Neutral are wound through a toroid.
> 
> There are a pair of wires coming out of the middle of the toroid. They go to a 
solenoid.  That solenoid, when it moves, trips the mechanical switch inside the 
GFCI and opens the circuit!
> 
> It is definitely a Rube Goldberg thing to look at - but it DOES work!
> 
> This is the GFCI that I removed from the Old Hair Dryer.  It has NO ground!  
It is a two prong device.
> 
> Bob - N0DGN
> 
> 
> 
>> On 2013-03-20 02:37 PM, rbethman wrote:
>>> Actually, it senses the current differential between hot and neutral.
>>> 
>>> It may seem tp be picking nits, but that IS how they do this. As
>>> another friend, an EE that works this field extensively explained, it
>>> should trip if a simple 15K resistor is put across hot, black, and
>>> neutral, white.
>> 
> ______________________________________________________________
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> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/mmfaq.htm
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> 
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> Please help support this email list: http://www.qsl.net/donate.html

------------------------------

Message: 4
Date: Thu, 21 Mar 2013 09:18:27 -0400
From: rbethman <rbethman at comcast.net>
To: r-390 at mailman.qth.net
Subject: Re: [R-390] GFCI issues
Message-ID: <514B08A3.3000400 at comcast.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Actually, the "toroid" structure that the hot and neutral are wound 
through is a toroidal transformer.

There are wires wound inside the toroid.  These windings under normal 
conditions, only see the field as balanced.  Thereby cancelling out any 
flow.

Yet, should there be an imbalance, these windings would develop a flow 
and indeed send their output to the little solenoid and cause the trip.

You would really have to have one open and in your hand to see how 
ingenious, elegant, yet simple design and device that it is.

The test button puts a 15K ohm resistor in the circuit to one leg.  This 
causes the imbalance to cause it to trip.

The reason for the distinctive snap from pressing the reset button, is 
that it re-latches the solenoid assembly and locks it back open.

I'm glad I did open it just to satisfy my curiosity!

It also now makes MUCH more sense as to why two of them back to back 
would/could be problematic.

I don't see how they *couldn't* interact.

It was a pain to get through all of this, BUT it was very educational!

Bob - N0DGN

On 3/20/2013 8:22 PM, Bob Camp wrote:
> Hi
>
> Keep in mind that there is no way a two wire device can trip a working GFCI 
all by it's self. It simply can't generate an imbalance between the hot and the 
neutral. There's no place else for the current to go. In order for it to trip a 
GFCI, there *must* be a third path, generally to ground. Assuming you are 
holding the two wire device up in the air (and not underwater) the only place 
for the current to go is through you. It's not going through the air. If it's 
going through you, you *would* notice it.
>
> Bob
>
> On Mar 20, 2013, at 4:04 PM, rbethman <rbethman at comcast.net> wrote:
>
>> I used Mr. Hacksaw.
>>
>> I can now look at the circuit inside.
>>
>> The Hot and Neutral are wound through a toroid.
>>
>> There are a pair of wires coming out of the middle of the toroid. They go to 
a solenoid.  That solenoid, when it moves, trips the mechanical switch inside 
the GFCI and opens the circuit!
>>
>> It is definitely a Rube Goldberg thing to look at - but it DOES work!
>>
>> This is the GFCI that I removed from the Old Hair Dryer.  It has NO ground!  
It is a two prong device.
>>
>> Bob - N0DGN
>>

------------------------------

Message: 5
Date: Thu, 21 Mar 2013 10:01:53 -0400
From: rbethman <rbethman at comcast.net>
To: R-390-List <R-390 at mailman.qth.net>
Subject: [R-390] GFCI info
Message-ID: <514B12D1.8020700 at comcast.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Go to the following link to get a PDF on the GFCI circuitry and 
functionality.

<http://www.nema.org/Products/Pages/*GFCI*.aspx>

Specifically: NEMA-GFCI-2012-Field-Representative-Presentation.pdf

This makes it very clear.

Bob - N0DGN

------------------------------

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