how do you all dispose of Ferric Chloride?

[Dave_B]

But my god the CNC route is a bit sledgehammer cracking the nut kinda thing don't you think!

For most of us, definately.  It would be a good way to go if you were making PCB's like GGG or Tonepad, since it could also drill the holes for you.  For me it's a solution looking for a problem.   

[orgaqualia]

I have a friend in the graphics industry who has a printer that uses actual metal foil for things like fake gold leaf on wedding invitations. I've often thought about the potential of that particular procedure. I would imagine that if you could get it to work on bare board you would be rather limited to small current designs as the film is very thin. But still, I keep thinking that there has to be a better way. all of these chemicals seem so primitive...

PS whats the best way to get rid of the developer for photo resist boards?

[MikeH]

Aww, don't feel bad guys, LOL!  I'm a little green, but I was working FOR companies that pollute, keeping them in compliance. Saw a lot of 'negative externalities'...and my company was very selective on what they 'saw'.  One thing I learned...there's always a down-side when we use chemicals.  FeCl is no worse than mineral spirits or muriatic acid over the long haul, and the amt. of copper taken from a board isn't huge.   I'm more pointing towards the property damage end of things than health.  The health risk is immediate and decreases over time...the copper build-up, iron and cl components accumulate over time.
 
So, if you would be ok to paint something out in your yard, you have the environmental skills to etch boards, lol.  Just take Mr. Hammer's advice, use the baking soda, and don't dump it on the ground!    A couple of phone calls might locate a good place to take it, or just dry it up & in the trash it goes.  Photographers have similar problems, on a larger scale (they use silver, very bad!), and manage to get by...
Good topic, worth talking about 

I used to be in Environmental consulting as well.  If you neutralize your etchants and turn them into bricks or whatever, big kudos to you.  But if you've flushed a little in the past, don't feel too bad; that's absolutely nothing in comparison to what industry has done to the environment.  The amount of etchant waste that comes from DIY pedal makers probably accounts for one trillionth of the polution on the planet.  But still, I'd certainly encourage anyone to dispose of toxic materials in a safe and environmentally responible manner.

[Transmogrifox]

Yeah.  I walk down to the stream behind my house and dump it in.  It's only a few hundred yards to the ocean...and we all know that dilution is the solution to pollution. 

Actually, I don't do that.  My last bit of etchant went out with my motor oil to HazMat.  Who knows if they dispose of it any better than dumping it in a creek, but at least they make me feel like a responsible citizen for using their services...

[puretube]

WOW: there is a nice lake here, right outside of town (~20 minutes by bike).

A pond were carpers are being bred (breeded?), where you can go skating when winters are like they used to be,
and where on summer weekends thousands of inhabitants go swimming, picknicking, bbq-ing, sailing
and we had an annual 3-day "Sea-Rock-Festival" there, too for 20 years...

The last 3 or 4 summers there was a blue-algal bloom each time when the weather was at its best,
and hence swimming was prohibited for weeks...


NOW they (the municipal government) found a solution to fight the problem
(which is mainly being caused by too much phosphates from the surrounding agricultural fields):

they actually are gonna dump Fe-Cl₃ into the lake:

https://secure.erlangen.de/eris/downloadPDF.do;jsessionid=aJ5R7rAUQglg;jsessionid=aJ5R7rAUQglg?id=1153533

5000 kilos per year...

well, I could help them out a little... 

[Paul Perry (Frostwave)]

Keep us posted on that one, Puretube!
I'd be really suprised if it works well.. ferric chloride in this application just works as a coagulant, so the algae sinks & decomposes. I think you will end up with a smelly lake!

[Meanderthal]

A pond were carpers are being bred

The last 3 or 4 summers there was a blue-algal bloom each time when the weather was at its best,
and hence swimming was prohibited for weeks...

I have a spring in my yard that had caused a big patch of mud to be in my backyard(down in the hollow), a big PITA to mow.

I planted weeping willow trees to drink it up... nope, didn't work... I got to thinking, since it's wet, why not have a pond? So I dug a 'test hole' about 3 feet deep, 1 foot wide, and watched the water level for a year. Yep, even in the hottest dryest part of mid summer, there was standing water. So I started digging a pond.

Well, the first year I got pea soup. Yuck! I tried a couple wal-mart solutions, but the damn stuff came right back. I tried scooping it all out, same results. Winter came, the goo subsided, and I got to spend some time not having to worry bout it for a while...

Then sping came. And MOSQUITOES! And pea soup. Well, I figured, go get some goldfish(carp) to eat the larvae, since they can survive in nasty water like that. Went to a pet store, bought 50 feeder fish for $5.00, dumped them in. Carrots for the pea soup...

And... the pond scum was gone in 2 weeks! This puzzled me, since the only thing I did was add goldfish...

I was at a store shortly afterwards, and saw some goldfish food on a shelf.  I looked at the ingredients. First on the list- algae. Well whaddya know, goldfish eat algae, not just bugs and stuff! Haven't had an algae problem since. Nor a mosquito bite. The pond is FULL of fish, and I don't feed them at all. Never saw a dead one yet.

Just a suggestion, but maybe more fish would help...(yeah, I know, it's not your personal pond to make those decisions).

[Meanderthal]

 Oh, and the 2 times I used FeCl I let it dry in the tray, then threw the whole thing in the trash. Took quite a while to dry.

BTW, I do NOT want to encourage anyone to dump it down the drain, but I worked building houses (masonry actually) for quite a while, including new, old, and historic old houses as well as commercial buildings, and have never seen a single copper sewer pipe. Nor heard of one. Iron, yes, though. Copper is just way too expensive to use for large pipes like that. PVC is the most common. Not trying to be contradictory, but just trying to keep the info accurate.

[km-r]

the river

[markm]

the river

....wait 'til pete moore gets a look at this.....
It's really NOT going to be pretty! 

[jonathan perez]

yeah, rivers only need water and fishys...



and occasionally the brunette down the road...

[km-r]

one weekend im gonna catch a copper-clad catfish in our river...

[puretube]

or I`m gonna bring my PCBs to the lake, to get them etched...

[markm]

or I`m gonna bring my PCBs to the lake, to get them etched...

[gez]

Took my Chevy to the levee, but the levee was green...

[puretube]

Keep us posted on that one, Puretube!
I'd be really suprised if it works well.. ferric chloride in this application just works as a coagulant, so the algae sinks & decomposes. I think you will end up with a smelly lake!

tomorrows local newspaper:

http://www.erlanger-nachrichten.de/artikel.asp?art=634480&kat=19

(sorry: german...)

[Paul Perry (Frostwave)]

I may have been wrong about the ferric salt being a coagulant, apparently the idea is for it to srtrip out phosphates by precipitating ferric phosphate (I would never have guesed this was insoluble!). This assumes the excess algae is caused by phosphate from farm fertilisers.
Well, we'll see! Ironically, in the ocean, algae growth is limited by there being not enough iron! The world is very complicated..

Keep up the reports, Puretube!

[KORGULL]

Any new/good tips on deactivating and/or disposing of ammonium persulphate? I'm saving it in a bottle and hoping it is something they accept at the yearly hazardous waste collection that is held in my area, but I'd like to know of options for neutralizing it.

[Paul Perry (Frostwave)]

The remains from persulphate, is going to be copper sulphate. Any unused persulphate gradually loses oxygen & turns to ammonium or sodium sulphate.
Copper sulphate isn't highly toxic, it is regularly dumped down drains to discourage root growth.
I wouldn't put it in a septic tank, though.

[stobiepole]

And if you have any dogs around your house, make sure you keep solvents away from them - they absorb them through the skin very easily which will make them deaf VERY quickly. And for those in cold climates - antifreeze is highly dangerous (dogs love the taste AND it kills them).

Things to consider if you're a dog owner.
Chris