Homebrew PCBs

On Sun, 15 May 2005 09:23:40 -0400, Alan King <alan@...> wrote:

> Stefan Trethan wrote:
>
>>
>> I wouldn't put normal silicone (not heat resist) in the oven with food.
>> the fumes are quite bad, only do when well ventilated.
>   Well I was thinking more along the lines of using the waste heat for
> something useful for a change after the cooking is done than about  
> making acetic
> acid casserole..
> Alan


Nah, i still don't like the idea. I tried to run it through the fuser to  
evaporate this liquid, but it doesn't work.
I think the temperature is just enough to break down normal silicone. I  
think it could work to reduce fuser temperature, because it seems at the  
beginning of a board (when the board is coldest) it doesn't sizzle.

Whatever, using normal silicone is not a priority for me. High temp  
silicone works and i accept the doubled cost for now, after all fiddling  
around with the temperature is a lot of work too. Right now i'm fighting  
with the printer for perfect geometry adjustment.

The things concerning the transfer so far are:


Do not put silicone on the first 7-10cm of the page or you will from then  
on have a paper coated drum.
(By the way, drums and light-sensitivity, how bad is it really? which  
precautions must be taken when working with drums?)

Work with relatively low pressure in the fuser.

Let cool before peeling off the paper.

Otherwise the results are pretty good.
I have a problem with creases forming on the last few cm of a page, but i  
hope to figure that out, and also for small boards it is not an issue.  
Also, if this particular printer gets eaten up by acetic acid i do not  
care that much, more like hope nothing is left...

It also needs to be cleared if the acetic acid does remain on the surface  
of cured silicone. I have wiped it with acetone to re-use and that does  
not seem to be a problem at all.


Much of my efforts is going into the distortion thing at the moment, to  
see if i can go ahead with the CNC or if there is no point.

ST