Homebrew PCBs

Yeah they are definitely pretty oxidized.. for example, where the sticker on
the plastic packaging sat this is noticeable difference in color.  And I
keep rubbing down with the acetone and still red dust comes off.  I'll try a
light sanding and see.. makes sense, these boards seem a little more
discoloured than the others.

 

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] 
Sent: Thursday, July 6, 2017 11:27 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Vintage PCB toner transfer problems

 

  

I haven't been following the thread, so hopefully i'm not redundant.

That vintage board may be much heavier than you usually use
i.e. 2+ ounce copper etc. so you may need to heat it quite
a bit longer to get up to transfer temperatures.

That stuff may be WELL oxidized, to the point you have to get drastic
to clean it enough for tt. I have used a medium wire wheel on a bench
grinder in the past. The scratches may also help the toner to stick.

HTH
=================

On Thu, 6 Jul 2017 08:40:06 -0700, you wrote:

>Hello,
>
> 
>
>A while ago I bought some vintage PCB stock from 1973. I was really excited
>about this as it allowed me to go the last mile in making a reproduction
>look authentic. However, I have discovered to my dismay that the toner
>transfer process is not working so well with these boards.
>
> 
>
>I've tried three media with my iron (I don't have a laminator):
>
> 
>
>Blue PCB transfer sheets. They stick wonderfully to the modern stock but
>not at all to this vintage stuff.
>
>Yellow toner transfer paper. Worked on the first two boards mostly, but now
>won't stick to any of the others I have at all.
>
>Magazine paper. This sticks and I get 90% of the image, but that's it. And
>only with much greater effort than usual.
>
> 
>
>I have scrubbed these boards with comet and a scothbrite pad. I note even
>after doing so I still get a fine red powder residue when wiping with
>acetone. So I'm wondering if maybe this copper has just kinda gone bad over
>44 years.
>
> 
>
>Another question - on a couple of boards I've used permanent marker to fill
>in gaps, but the etchant always eats it away like it wasn't there. Is there
>a particular brand I should be using? This has happened with both
>vinegar/peroxide solutions and FeCl.
>
> 
>
>Thanks!
>
> 

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