Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

Hi,



Having gotten beyond toner transfer and etching (more below), I'm
finally assembling my very first board. I find that it's harder to
solder than other PCBs I've purchased. The solder pools on the wire or
pin and doesn't easily attach to the pad. I expect the solder to "suck
up" when the area is hot enough, but it doesn't.



Could it be that the Liquid Tin-coated pad is less solderable than bare
copper? Could it be the lack of plated-through holes that prevent it
from "sucking up?" Must I replace my elderly (though good at all other
jobs) temperature-controlled Ungar soldering iron? Could it be that I
need a new tip, even though it looks perfect? I'll try using liquid flux
next, but any advice is appreciated.



Regarding etching, I used Pulsar's sponge method. It worked very well,
though it took a bit longer than claimed. Afterward, though, I would up
with a black, extremely filthy sponge. According to an article I earlier
uploaded, Sodium Hydroxide (NaOH) is supposed to neutralize FeCl3,
producing salt water and a non-toxic precipitate. Well, I tried to find
Sodium Hydroxide. A pool store and a hardware store never heard of it.
(Maybe I should have asked for lye or caustic soda instead.) I thought
manufacturers were supposed to list ingredients, but that apparently
doesn't apply to drain cleaners. I finally bought Drano Kitchen
Crystals; at least they warned against misuse of Sodium Hydroxide.



Sooo, I added enough water to cover the sponge in my (fortunately)
disposable plastic leftover tray - about 14 oz -- and poured in an
(eyeballed) tablespoon of Kitchen Crystals. I wound up with a brown mess
with brown things floating in it. Frankly, it looked like diarrhea! Can
anyone hazard a guess at what this stuff is? Without knowing what it is,
I don't want to put it in my toilet; I don't need a plumbing bill! Our
storm drains around here drain to the ocean and I'd rather not kill any
fish I don't have to. Right now, I'm planning to hold it, sponge
included, until our next HazMat collection day and let the county handle
it.



For the future, how should I clean up after etching? Should I just
figure on killing a sponge for every job? Would re-using the same filthy
sponge for several jobs be ok before giving it to HazMat? I'm thinking
of using Pulsar's "Baggie" alternative to the sponge method next time.
Has anyone tried this? Does it work well?



Jim





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