Homebrew PCBs

On Fri, 18 Oct 2013 21:14:10 -0600, you wrote:

>
>
>On 10/18/2013 6:18 PM, twgray2007@... wrote:
>> Is anyone else using the HP LaserJet P1006 printer for toner transfer?
>> If so, has anyone been able to get the printer to register correctly
>> betwen multiple printer passes?
>
>Me thinks you are trying to make a silk purse out of a sow's ear in 
>addition to chasing the wrong spook.
>
>Unless  you are  trying to do something special, the  P1006 puts down 
>enough toner to do the job in a single pass.  I run mine at 600 dpi and 
>all the paper types seem to work about as well.
>
>The critical step is transferring the toner to the board.  If none is 
>left behind, you have a winner.  More toner on the paper is not going to 
>assure a good transfer. How you get a good transfer is the step you have 
>to work out yourself.  There are lots of  ideas out there but I have not 
>found one that works 100%. I am still trying.
>
>I don't make bad boards but still make a lot of bad transfers. 
>Fortunately, they are nearly free and I have lots of time.
>
>Jack
You can also "overcook" the transfer process. If the paper
coating contains certain types of plastic it is quite possible 
to use too much heat for too long and end up fusing the
surface coating into the paper. Note too that the size of the
board often makes a major difference. The mass of copper being
heated and the surface area available to radiate from the board
can make a major difference. With a 2x2 board I iron for about
70 seconds, while a 4x6 board requires about 150 seconds. YMMV

IIRC my iron is about 430F.  

Sometime back someone suggested placing a paper towel over the board
during ironing. I fold one in half with the board inside. It seems to help.

Keith Bowers WB4LSJ- Thomasville, NC