Homebrew PCBs

Does colophony really create a hard coating similar to laquer? I know
flux removers are commonly available, and I have used them after using
 "rosin core" solder on small boards, because, if I don't clean off
the flux residue, the board will be sticky and collect dust, as I
learned with a small SMT pcb I made not long ago.

Is colophony different from common "rosin"?   Or is there something
about adding a solvent that leaves the flux harder after the solvent
outgasses than when it is when the flux it is in the core of flexible
solder?

Thanks,
Paul

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:
>
> Alan,
> 
> as i said it is mainly colophony resin (the same flux used in many
solder  
> wires) and alcohol.
> I know people who simply mix solid chunks of colophony resin with  
> methylated spirits (ethanol alcohol) and apply it with a paintbrush.
It  
> works the same as my spray, but since a 400ml can costs only 8 eur
here in  
> Austria i simply buy the spray.
> 
> Colophony solves in alcohol, acetone, paint thinner, etc.. But i
recommend  
> methylated spirits (ethanol) since acetone gives a ugly dull finish.
> 
> In the past natural resins like colophony were widely used in
lacquers for  
> wood protection and stuff, but not any more.
> 
> The product i use is here:
>
<http://www.crcind.com/csp/web/ProdDisp.csp?lng=3&country=ALL&product=FLUX%20SK%2010&brand=KOC>
> 
> But as said you can just make your own if you can't get it. colophony  
> resin should be readily available. Get as light a color as you can,
> while you won't see it in the thin layer on the PCB it's still better.
> 
> 
> 
> 
> While looking for the solder lacquer i found a very interesting thing:
> <http://www.buerklin.com/gruppene/KapL/L177100.asp?l=e>
> 
> I've spend many, hours probably, thinking about using a metal brush
that  
> is heated in some way, but never actually got around to trying it.
Seems  
> it's time now. I reckon those are brass or steel bristles. Maybe even  
> stranded wire or desolder braid will work. easy to build.
> 
> ST
> 
> 
> 
> 
> On Tue, 10 Jan 2006 15:53:52 +0100, alan00463 <alan00463@y...> wrote:
> 
> > I will look for "solder lacquer spray".   Nearly all the websites that
> >
> > mention are in the U.K.   Maybe it's called something different in the
> >
> > U.S.A.     I am wondering if this is the same stuff you would buy in a
> >
> > paint store in the U.S.A. for protecting wood?    Or is it something
> >
> > different?   I couldn't find it in Mouser, Digikey, or JameCo
> >
> > catalogs, even looking under the generic heading "chemicals".
> >
> >
> > The closest I found was "silicone  conformal coating" and "urethane
> >
> > conformal coating".   These are anti-fungal, anti-moisture coatings
> >
> > for protecting the circuitry from harsh environments.   Probably not
> >
> > what you had in mind.
> >
> >
> > Stefan, the "solder lacquer spray" you use is transparent, is it not?
> >
> > Does acetone dissolve it once it has hardened?   Can you see where it
> >
> > has been removed vs. where it remains on the copper?
>