Sounds like you don't have all the resist removed.
Bruce
--- In Homebrew_PCBs@yahoogroups.com, "Jim Barnes" <jim@...> wrote:
>
> 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
>
>
>
>
>
> [Non-text portions of this message have been removed]
>