Homebrew PCBs

Have you tried solder bearing plumbing paste? They make a paste that
contains small particles of solder similar to SMD paste, not just
flux. <http://www.hausundwerkstatt24.de/bilder/produkte/gross/8015.png>
I used that and it worked just fine, melting it with a hot air gun.

Regarding the hotplate, it does work to heat through the board from
the bottom. I often reflow SMD solder with that method, and there are
industrial hot plate ovens just like it for single sided boards. I use
240°C for leaded solder. Not sure how much of a disadvantage the
(leadfree) plumbing paste may be with a hotplate.

I believe roller tinning (using a solder bath and transfer roller just
like a printing press) is superior. It would also not be hard to make
a tinning "iron" which holds a bunch of wadded up copper or brass
strands as a paintbrush.

ST





On Sat, Jan 12, 2013 at 3:25 PM, Rick Sparber <rgsparber@...> wrote:
> ST,
>
> I failed to mention that I am using plumber's solder paste and paint the
> board using an old tooth brush. I tried reflowing the paste with my hot air
> gun but it didn't seem to matter. The brush put it on thin enough.
>
> The SMD paste contains tiny specs of solder so it is not the same as
> plumber's paste. It would be cool if there was a way to take 1/8" diameter
> solder and grind it up into tiny particles. Then it could be mixed with
> plumber's paste and used to coat the board. Heat the board in a toaster oven
> and it would be coated. Then wash to remove excess flux.
>
> Rick
>