Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> 
wrote:
>
> The simplest way to understand it is to buy that paper and test 
it. 
> Then let us know. The paper is cheap, you said, right?  Mike
>


I am not at all convinced one paper is better than another.  During 
the last few months I have been using up some glossy HP Inkjet 
paper. It's pretty heavy stock, but it's been working most of the 
time.

The first two variables that sort of monkey wrenched the paper thing 
is this...

With one brand of PCB material, the transfer was easy and perfect. 
The same day and within minutes of doing one with "Board A", I 
couldn't get anything to work with "Board B".  Both were single 
sided, 1 Oz, 1/16 thick stock but by different companies.

Then I tried pre-etching the boards (Brand B) and that took care of 
the transfer problems.

This particular paper would take forever to soak off (it is thick) 
and would leave a film.  Then, using the same paper a couple of days 
ago, I transferd the image to a board, tossed it in some water and 
the paper came right off - no white residue - same paper as I was 
using.  I think there might have been two differences...

1) When I would have trouble getting the paper off- I was letting 
the board cool before putting in water.  The humidity was higher.

2) When the paper came off and didn't leave any residue, I didn't 
let the board cool before putting in water and the humidity was much 
lower (very cold outside).

I don't think it is iron temp - I set it and check it with a digital 
thermometer.  I don't think it is presure, I press the same way 
every time. I don't think it is pressing time - I watch the second 
hand of the clock and count off my 20 seconds for each pressing.

So, I have a hunch there is much more going on that just a 
particular brand of paper.  I think there is much to do with 
enviroment and even technique.  

In my last battle with bad transfers (with board brand B), I tried 
magazine pages and frankly found that to perform as good as anything 
i have tried so far.  I just have to remember to use that, rather 
than reaching for "printer paper".  

It sure is interesting though seeing all the goods, the bads, and 
the downright uglies when going through this process!

Chris