Homebrew PCBs

Sulfamic Acid (H3NS03) is correct for this formula. I have also seen formulas that use Sulfuric acid and suspect they work in a similar way. The Sulfamic acid is a white powder so none of the chemicals in the formula are liquid.  

 Wikipedia: "When compared to most of the common strong mineral acids, Sulfamic acid has desirable water descaling properties, low volatility, low toxicity and is a water soluble solid forming soluble calcium and iron-III salts. Its also finds applications in the industrial cleaning of dairy and brew-house equipment.  -- "The deprotonated form (sulfamate) is a common counterion for Nickel(II) in
electroplating."



Craig

--- In Homebrew_PCBs@yahoogroups.com, "fredbutz" <fredbutz@...> wrote:
>
> You sure it isn't Sulfuric Acid?
> I saw another formula, same chemicals, but used Sulfuric Acid instead of Sulfamic Acid.  I just want to try the Ham Radio Magazine formula.
> 
> --- In Homebrew_PCBs@yahoogroups.com, "designer_craig" <cs6061@> wrote:
> >
> > I have very good luck with elctroless tin.  The formula I use came from the September 1971 issue of Ham Radio magazine.  
> > 
> >                    .5g Stannous Chloride
> >                     2.0g Thiourea
> >                     3.0g Sulfamic Acid
> >                   100.0 mL Distilled water
> > 
> > The solution is ued cold, I never tired heating it.  It plates up in a few minutes and does a goog job but can't be use as a resist for further etching.  The solution does not keep and I always make up a fresh batch for each board making session.  I would usually mix up less than 100 mL depending on the size and number of boards I was doing. 
> > 
> > Craig  
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, Alessio Sangalli <alesan@> wrote:
> > >
> > > Hi, as I am perfectioning my PCB making, I reached a point where I can 
> > > do very good boards, but especially if I am making a bigger, double-face 
> > > one, with huge ground planes, tinning takes simply too much time, and if 
> > > I want to do it properly, I end up wasting a lot of solder wick braid to 
> > > remove the excess tin.
> > > 
> > > I've read past messages but I was not able to find a method that is well 
> > > documented and can be considered a viable solution for a hobbyst that 
> > > makes only few boards per month.
> > > 
> > > bye
> > > as
> > >
> >
>