Homebrew PCBs

I had not tried alcohol.
I've been using 220 grit sandpaper per your advice...since  a year ago?
Then I used acetone to clean up the fingerprint oil and sanding dirt.
Not that fingerprints are a problem... I always wear heavy 9mil nitrile 
gloves when playing with PCBs.

Is the iso-prpyl wipe anything more than or different than using a tough 
paper towel and 91% alcohol?

I had experimented with transfer craft metallic foil but really didn't 
need the foil after using a Sharpie.
I can see using the foil for massively complicated or detailed circuits 
that would test patience tracing a whole board with a Sharpie. But 
nothing I do is that complicated.



On 07/09/2017 10:29 AM, AncelB mosaicmerc@... [Homebrew_PCBs] wrote:
>
> Genuine or non oem HP toner works for me. For the pitting problem I
> transfer craft metallic foil on top of the toner before etching. It's a
> well known practice and reliable.
>
> Rather than using acetone or citronella to prepare/clean the copper I
> use 220 grit sandpaper and an iso-propyl wipe which makes the toner
> 'grip' the oil free copper. Even fingerprints can interfere so handle
> the edges of the PCB. As a test I polished/lapped copper and tried the
> identical transfer with poor results all other things being the same.
>
> Also, before I did the metal foiling, I used to use a silver sharpie to
> 'fill' in the toner transfer for any breaks or potential pitting and
> then etch.
>
> I have done literally hundreds of double sided boards and even boards
> for RF use to 1Ghz with toner transfer. It works.
>
> Ancel
>
>