[sdiy] PNP Blue questions

[David G Dixon]

> Which side to print on?

The side with the blue shit on it (not the shiny plastic side).

> Which is best iron temp?

I set my household iron to about half (permanent press?)

> Time for ironing?

I give it about two minutes.  I press down firmly, and move the iron in a
slow circular pattern, in both directions.

> Should I put a piece of paper in between the iron and the 
> PNP?

I do.  This protects the plastic sheet from buckling (and catching on the
iron).

> Is the a good way to tell if the design is transferring 
> - that is, is there a good way to visually check if I've 
> ironed long enough?

If only.  I never know until I quench (under a cold tap) and peel.
Sometimes I get a nice surprise, sometimes a nasty one.  I almost always
have some minor fixing to do, particularly around the edges.  This I do with
a fine-point black Staedtler Lumo permanent marker (they work better than
Sharpies in my experience).

> I plan on using FeCl3 for PC boards. Is this a good etchant 
> for die cast aluminum as well? I want to etch the cases for 
> the projects too. 

Don't know, as I use CuCl-HCl-H2O2.  This works great for me.

> I've seen some examples and they look pretty cool. Some of 
> the techniques use electric etching,but I don't see the need 
> for this. Would peroxysulfate be a better etchant?

Don't know.

> I'm sure trial and error will help, but I don't want to waste 
> much PNP stock and I certainly don't want to mess up my nice 
> laser printer.

I hear ya!

DO NOT PUT PNP BLUE THROUGH YOUR LASER PRINTER WITHOUT A PAPER BACKING !!!!!
IT WILL MELT OR BUCKLE.

Here's what I do: Print out the circuit on paper first, preferably so it
prints toward the bottom of the page.  Then cut the PNP out to the proper
size, leaving a bit extra in the vertical direction (which should be shorter
than the lateral direction -- this works better).  Place the PNP over the
printout (blue-shit side up, of course) and apply one strip of clear plastic
tape across the top edge, smoothing it down well with you finger.  Then run
this through the printer using the external feed chute.  When it comes out,
quickly run your finger under the PNP blue to disattach it from the paper
(it will stick down by static electricity, and my get overly curved if you
don't lift it up quickly).  Then simply cut the PNP blue off just below the
tape strip, cut off some of the blank paper above to use as a cover while
ironing, and you're ready to rumble.