Old Etching solution

Ammonium persulfate doesn't stain, but is a little slower than ferric chloride. It is also a little more environmentally friendly.

Take a look at

pages 10-13.

Jim

It is much better than ferric chloride. It also has a great advantage that it won't etch nickel or solder plated traces that allows for making plated-through holes.

Unfortunately it has one _MAJOR_ deficiency -- the etching solution don't last. It is OK for manufacturing when solution is discarded at the end of day but for a hobby use when one board is etched once a month or so it is a big waste.

The best one for hobby use is cupric chloride. It is cleaner than ferric chloride and the solution lasts forever. Dunno how it works on nickel/solder plated copper but usually it is not an issue in hobby use because it almost never involves PTH that requires much more chemicals and those chemicals are quite expensive and not all of them are readily available for a hobbyist.

Here in Portland OR, if they find paint cans of any description (full,empty, solid, thick) not only will they dump the cans all over your yard but also send a rather strongly worded letter not to even think about doing that again. So i was interested in an alternate disposal method. WAIT! Maybe i could send them as a gift to His Obamaness?

You can drop off cans of paint or mmost household chemicals at any of the county's transfer stations or the county landfill around here. (N. Central Florida) They will take all kinds of things, like the truckload of old propane tanks I hauled off after the old man next door died. His relatives descended like locusts to take all his tools, but left all the chemicals and tanks behind.

That's just stupid, though wouldn't expect otherwise from the weenie left (coast). There is *nothing* in paint that will harm a landfill, particularly once dried. Nothing to spill on the way to the dump, either.

The only good one is to *MOVE*.

...and have the Secret Service throw them all over your yard and write the strongly worded subpoena?

Robert Baer wrote in news:d9mdne2DYKPZELzQnZ2dnUVZ snipped-for-privacy@posted.localnet:

They'd get you for using Weapons of Mass Destruction,toxic wastes. ;-)

(That definition has expanded greatly,it no longer only means chemical/biological/nuclear weapons.)

Perhaps Oregon has a law requiring sellers of paints to accept leftovers for recycling,as auto battery retailers have to for lead-acid car batteries? the same goes for auto oil,many places accept it for recycling.

Phoenix has regular hazardous waste disposal days at local parks. You drive thru and don't even get out of your car/truck. They unload and sort according to type... tires, car batteries, paint, solvents, etc. ...Jim Thompson

Which pushes the problem off onto future generations when the mortar mix decays and puts that stuff into the ground water.

That seems to be a typical thing for our generation ... push the problem onto our descendants.

Jim

Utter nonsense.

Please!

That sounds like a problem, not a solution.

Its not. Eventually the copper will leach out. It is much better to have it disposed of properly so the copper can be extracted. BTW the copper price has never been higher!

More, but different class of nonsense.

Ya? Under what conditions? Copper hydroxide and carbonate are wonderfully insoluble, and readily formed on interacting with any regular soil (not to mention the chemicals in mortar itself). The chloride and sulfate are the only soluble salts of note, and these are only present around mine drainage and acid rain. In the latter case, it's not enough to worry about (at least not in the last century). In the former case, you've got much bigger problems to worry about, arsenic for one.

Other factors include the binding of copper ions to clay particles and organic substrates. These typically slow down or stop the movement of all contaminants in the soil.

Now *this* is a good reason! :)

Tim

Late at night, by candle light, Sergey Kubushyn penned this immortal opus:

Yes, CuCl2 is real neat once you get it going. Mine's lasted for a couple of years by now, with an average of one board a month without needing reactivation. It even seems to be working better now than when new. After use store it covered with enough air space to reoxygenate by itself. The cover is to avoid evaporation and release of HCl fumes that will corrode anything in their sight.

- YD.

All sorts of interesting chemicals are present in paint, aside from the flamable resins and solvents some of the pigments are toxic.

Over here some paint retailers will take leftover paint (for recycling), as will the hazmat people at the runnish transfer station.

Refusal of dried paint me be due to cases where the paint isn't tried all the way through.

Water is toxic.

will the

Sure, why waste it.

The alternative is worse. People will flush it down the sewer and then throw away the can. Same deal as the disposal of appliances. Make it "free" and people dispose of them in a "green" manner. Make it impossible and they'll become scenery.

Hobby quantities here can be disposed of at the county recycling site.

I thought there was something you could add that would precipitate the copper and make the rest safe to dispose of. What I remember was lye, but I heard it a real long time ago.

I think it was Spehro Pefhany who suggested washing soda, sodium carbonate, which turns the ferric and copper chlorides into ordinary salt and iron and copper carbonates, which are essentially dirt.

Cheers! Rich