Overcoating suggestion: I've started using "Future" acrylic floor wax to prevent the copper traces from oxidizng. Just wipe a thin film on and let it dry. Soldering though it is no problem. TANSTAAFL! Myc On 7/13/06, Stefan Trethan <stefan_trethan@...> wrote: > > On Thu, 13 Jul 2006 03:13:43 +0200, warrenbrayshaw > <warrenbrayshaw@...> wrote: > > > > > I have always used Shellac to protect the newly etched PCB. Shellac is > > made by dissolving commercial Shellac flakes in methylated spirits. > > French polish is the same thing. Also I have a tin of product from the > > hardware store and it is known as "Patent Knotting." > > The Shellac goes on the colour of varnish and prevents oxidation and > > can be soldered through. It appears to react like a flux when soldering > > through it. > > > > I use colophony resin. Basically tree resin with the turpentine removed. > It's the same flux as used in rosin core solder wire. If given enough time > to dry a laquer made of this will be dry and hard to the touch, although > it does stay sticky longer than normal laquer (i believe this may be > caused by water in the impure alcohols). It protects against corrosion, > and acts as a flux during soldering. While it may not be ideal for the > highest impedance circuits i have not had any problems so far. > I used (and still use) a ready-made spray can version of it, but i spotted > colophony chunks at the chemicals shop, very good almost transparent > quality. The lighter in color it is the lighter the flux residue will be, > the dark brown stuff looks awful after soldering. The chunks can be solved > in alcohol just like shellac to make a laquer. > I've also molten colophony into the little compartments at the end of my > solder spool (the compartments to keep the plastic stiff). It's great to > help with tinning wires. > > I always thought shellac is a tree resin, but now i looked and it is > actually produced by a beetle. I had no idea.. > > ST > > > > Be sure to visit the group home and check for new Links, Files, and > Photos: > http://groups.yahoo.com/group/Homebrew_PCBs > > If Files or Photos are running short of space, post them here: > http://groups.yahoo.com/group/Homebrew_PCBs_Archives/ > Yahoo! Groups Links > > > > > > > [Non-text portions of this message have been removed]
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Re: [Homebrew_PCBs] Re: Overcoating/soldermask
2006-07-13 by Myc Holmes
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