Homebrew PCBs

thanks.  here's the state of my "operations":

paper: I'm using magazine semi-glossy.  I'll try some of the coated 
inkjet paper.  I did have a couple of sheets that I used a while ago 
and think it had the same problem but I could be misremembering as I 
was fussing with learning the process.  by the way, passing the paper 
though the copier multiple times to increase the amount of fusing 
seems to have no effect.  it does come out hot so I know its 
getting "cooked".

toner density:  I've played with this a lot.  really cranked it down 
and even at super light settings I am seeing the blotchiness along 
with complete drop out due to too little toner.  In general, I keep 
it on the light side.

heat:  I think I've got this right as i started high and kept 
dropping it until the toner was not adhering, then kicked it up a 
bit. I'm getting good aherence. Using the aluminum sheet metal seems 
to improve the uniformity of the heating but there is still some 
blotchiness.

pressure:  I still think this, along with uneven heating, is part of 
my problem.  Its hard for me to control which is why I thought the 
metal plates would do a more even/uniform job.

I'm not going to obsess over this blotchiness as it doesn't keep the 
board from being usable, it just doesn't look super clean.  I'll keep 
at it so Me Etch Pretty, Someday.

--- In Homebrew_PCBs@yahoogroups.com, "poitsplace" <lmburt@e...> 
wrote:
> --- In Homebrew_PCBs@yahoogroups.com, "Phil" <phil1960us@y...> 
wrote:
> 
> > thanks for the reply.  I dont think the toner 
> > smearing is due to movement of the paper.  the 
> > toner is getting blotchy - a straight line will 
> > have varying width but is still straight.  
> > Nearby features will be fine.  If my wife ever 
> > gives me back MY digital camera, I'll post pix.  
> > Its significantly better with the plate.  I've 
> > tried cutting down the toner (easy with the 
> > copier) but with only a little difference.  When 
> > I've used too much pressure, it really gets bad.  
> 
> Two things I can think of.  
> 
> First off, you may have the printer/copier set too 
> dark.  Too much toner will make it smear on melting.
> 
> Second, what kind of paper are you using?  Glossy
> (or semi-gloss) printer paper will tend to smear
> because there's nowhere for the toner to flow but
> outward.  If you use the standard coated inkjet 
> paper...which looks like it's been painted with a
> "flat" paint (as opposed to glossy) excess toner
> can flow between the grains.  This greatly reduces
> the sideways flow.
> 
> It's pretty easy to find coated inkjet paper in
> an office supply place like office max.  Here's
> a page from an article that mentions a couple 
> ways to tell if something is coated inkjet paper
> (sorry for the long link)
> 
> http://www.extremecooling.org/ec/modules.php?
> name=Content&pa=showpage&pid=73&page=2
> 
>  
> 
> 
> > --- In Homebrew_PCBs@yahoogroups.com, Alan King <alan@n...> wrote:
> > > Phil wrote:
> > > > One of the things that I've been having trouble with on toner 
> > > > transfer is smearing due to either incorrect pressure or too 
> much 
> > > > heat.  My theory is that the smearing is happening because I 
> have 
> > to 
> > > 
> > > 
> > >    Metal plates are not a bad idea and can make for more even 
> > results.  But the 
> > > iron can also work great by itself, holes and moving it 
shouldn't 
> > be a problem. 
> > >   Use the tip of the iron, and only tack down one corner of the 
> > print good 
> > > enough to stick well.  Using the tip work a diagonal line 
through 
> > the print, 
> > > then work out from the middle diagonal line to the other 
corners, 
> > then go back 
> > > over and give good heat and pressure to the whole board.  If 
> you're 
> > doing the 
> > > whole iron at once at first, you're very likely not getting the 
> > toner stuck well 
> > > first and shifting things slightly while initially moving the 
> > iron.  You want to 
> > > work a good tacking in first without shifting anything, then 
get 
> > the good 
> > > transfer heat and pressure to get most of the toner on the 
board.
> > > 
> > >    And if you're not already doing it, you should run the print 
> > back through the 
> > > printer several times for the extra fusing before the 
transfer.  
> > Much improved 
> > > the results from my transfers.
> > > 
> > >    But it may still all be just thick toner from large 
particles, 
> > and you'll 
> > > probably never get everything consistent enough to always get 
the 
> > same results 
> > > from thick toner.  The range between too much heat and pressure 
> and 
> > too little 
> > > is just too narrow with a large easy to smash particle.  Even 
> with 
> > the metal 
> > > sheeting it may be hard to keep things consistent.
> > > 
> > >    I only ever really got OK results from previous attempts, 
> never 
> > the good to 
> > > excellent that I since got from the 600 DPI printer.  I really 
> need 
> > to go back 
> > > though and try the other techniques I now do with the other 
> > printer, and see how 
> > > much of the quality loss is really just the toner and 
> resolution.  
> > I imagine 
> > > it's most of it though, good results came fast and easy on the 
6L.
> > > 
> > > Alan