Homebrew PCBs

Is the etching mask created from a laser printer conductive? Could the 
same process be used to create a solder mask. 

I don't have a laser printer so I cannot make the measurment. I have to 
go to Kinko's to make the etching masks.

Bob Macklin
Seattle, Wa.

"Bob Macklin" <rottenrobbie0@...> writes:
> Is the etching mask created from a laser printer conductive? Could
> the same process be used to create a solder mask.

Toner's plastic and, I think, carbon.  I tested a sample and no, it
doesn't seem to conduct.  However, it's also not heat resistant.  See:

http://www.delorie.com/electronics/alarmclock/20070705-power.html

At the center pin of U400 (lower left, the 7805), you can see the
solder went right over the toner line.  Granted, there's a lot of
solder there... quick test, as I still have that board... nope, I
tried soldering a trace that had toner on it, and the solder went
right through it as if it weren't there.

Interesting enough, the toner did survive the hotplate reflow.  I
suspect that's just because nothing was there to physically move it,
so it just re-solidified in place.

My interest is in a coating that protect the copper
from oxidation with age. I don't have a provlem
soldering.

Bob Macklin
Kent, Wa.

On Sun, 30 Sep 2007, Bob Macklin wrote:

> My interest is in a coating that protect the copper
> from oxidation with age. I don't have a provlem
> soldering.

How about plating the copper with Kool-Amp silverplating powder?  I've
also seen transparent enamel sprays used (like candy-apple green).

-- 
David Griffith
dgriffi@...

A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?

In a message dated 9/30/2007 8:57:48 P.M. Central Daylight Time,  
rottenrobbie0@... writes:

My  interest is in a coating that protect the copper from oxidation with age. 
I  don't have a provlem soldering.<<
Before any other "chemistry" to the board, TIN-PLATE the copper (just a  
"hot-dip" for 20 min. operation).  Makes it nicer to solder, and protects  the 
copper from "turning".  There is a dry "crunchy" chemical called  "Tinnit" from 
Kepro, I think it is.  Haven't used it in SO long, I forget,  now.  Dissolve, 
use heated.  Has a definite "shelf-life" and "goes  bad" if not used up within 
a few weeks (days?).
 

 



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[Non-text portions of this message have been removed]

In a message dated 9/30/2007 8:57:48 P.M. Central Daylight Time,  
rottenrobbie0@... writes:

My  interest is in a coating that protect the copper from oxidation with age. 
I  don't have a provlem soldering.<<
OOPS!  forgot:  After you are done soldering, if a "one-sided"  board, wash 
off the "rosin flux" with lacquer thinner and a toothbrush (let it  dry 
completely before re-use.  Else the taste is very bad!).
 
Then, spray the "bright" just-soldered/flux-free bottom with clear Krylon,  
etc.  
 
IF you have some conductor on the top, you have to be VERY careful using  
Q-tips or whatever to clean off the bits of flux here and there, among the  
components on top.  Be SURE and mask off all IC-sockets, screw-terminals,  
solder-posts, etc., and then spray the top, but be SURE not so much that it  "runs all 
in" the IC-sockets, etc!  Takes reasonable hand-care and maybe a  bit of 
experience!

 
Jan Rowland



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[Non-text portions of this message have been removed]

Bob Macklin <rottenrobbie0@...> writes:
> My interest is in a coating that protect the copper from oxidation
> with age. I don't have a provlem soldering.

I've been using Liquid Tin from MG, the board in that photo is one
example.

On Monday 01 October 2007 00:44, JanRwl@... wrote:
> In a message dated 9/30/2007 8:57:48 P.M. Central Daylight Time,
> rottenrobbie0@... writes:
>
> My  interest is in a coating that protect the copper from oxidation with
> age. I  don't have a provlem soldering.<<
As an "aftercoat" you might try some of the spray "clearcoat" that Walmart 
sells in the automotive section (assuming you are inthe US). It shold be 
tougher than the clear Krylon.
-- 
Keith Bowers - Thomasville, NC

> > My  interest is in a coating that protect the copper from oxidation 
with
> > age. I  don't have a provlem soldering.<<
> As an "aftercoat" you might try some of the spray "clearcoat" that 
Walmart 
> sells in the automotive section (assuming you are inthe US). It shold 
be 
> tougher than the clear Krylon.


I use Clear Lacquer Spray, get it in the paint dept of whatever Home 
Improvement Store you have in your area.  I also do positive resist and 
leave the resist on, spray with clear lacquer after soldering.  See the 
PCB on the home page of this group.


Ben

I did some tests using three types of resists; the results are in
Ted-KX4OM in Photos. I tried Future Floor Finish, spar varnish, and
PolyCrylic.  All three are good for protection after etching.

PolyCrylic was by far the most difficult to solder through.  Future is
very easy to solder through.  It is not so good as a resist.  Future
is pleasant to use; it smells really, really good when soldering :)
One bottle is cheap, and will last a lifetime, give or take a couple
of years.

The only downside to Future is that if any chemicals are still present
on the board after washing, it will turn into a green crackle finish
at the location of the chemicals.

Future is also good for applying decals, homemade, or otherwise.

Regards,
Ted 

--- In Homebrew_PCBs@yahoogroups.com, "Ben" <bhleavi@...> wrote:

>
> > > My  interest is in a coating that protect the copper from oxidation 
> with
> > > age. I  don't have a provlem soldering.<<
> > As an "aftercoat" you might try some of the spray "clearcoat" that 
> Walmart 
> > sells in the automotive section (assuming you are inthe US). It shold 
> be 
> > tougher than the clear Krylon.
> 
> 
> I use Clear Lacquer Spray, get it in the paint dept of whatever Home 
> Improvement Store you have in your area.  I also do positive resist and 
> leave the resist on, spray with clear lacquer after soldering.  See the 
> PCB on the home page of this group.
> 
> 
> Ben
>

If I want that "extra touch" for homebrew PCB's (say, something
used for a presentation) I'll use model candy spray paint (Testors).  
Candy green looks just like a screened resist, and solder burns
through it just as readily as anything else.  Candy blue and red
also look great.  Otherwise for "production" I usually use $1.99 
clear enamel.



Mark K5LXP
Albuquerque, NM