Rescuing 2 sources and tagging 0 as dead.) #IABot (v2.0.1
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FeCl<sub>3</sub> is toxic and harmful to the environment – do not flush spent etchant down the drain. After use leave the FeCl<sub>3</sub> to stand still for at least a couple of days, the copper precipitates to the bottom, leaving still useful etchant on top. Pour this into another container. Add pure sodium bicarbonate (NaHCO<sub>3</sub>) aka baking soda to the thick mud at the bottom. The NaHCO<sub>3</sub> will react with ferric chloride rendering the solution relatively harmless to the environment. Do only a little bit at a time, waiting for the reaction to settle down each time. The reaction will produce a substance 7 to 10 times the volume of the solution, any spillage will contain still active FeCl<sub>3</sub> that will stain whatever it comes in contact with. Keep adding the NaHCO<sub>3</sub> until the rust-coloured mess is fairly dry in texture. It can then be disposed of along with the household waste.<ref>[http://www.diystompboxes.com/smfforum/index.php?PHPSESSID=2721ef0370b6f7ad578168a1c3200a26&topic=50426.msg377103#msg377103 Re: how do you all dispose of Ferric Chloride?] by Mark Hammer, 15 October 2006</ref>
=== Alternative etchant to FeCl<sub>3</sub> ===
Cupric chloride etchant is very similar to ferric chloride, but is simple to regenerate, there are no disposal problems,<ref>''[http://www.xertech.net/Tech/CuCl_ech.html Etching Circuit Boards Using Cupric Chloride and Acid Solution]'' by Stephen Kasten</ref> and doesn't stain everything it comes in contact with. It does use more dangerous chemicals. Open Circuits wiki discusses a variety of other [https://web.archive.org/web/20140810173425/http://www.opencircuits.com/Chemical_Etchants chemical etchants].
== Tinning ==
Tin-plating a PCB makes it a lot easier to solder and makes working with [[SMD]]s much easier. Use room-temperature tin plating crystals e.g. ''Seno Immerse Tin Crystals'', these produce a good finish in a few minutes but can be expensive. Only make enough tinning solution to cover a PCB in the tinning tray. Keep the solution in a concertina-type bottle to exclude air. Also avoid contamination with metals other than copper. Thoroughly rinse and dry the PCB before tinning. Use a separate tray and pair of tongs specifically for tinning, and rinse them after use. If the solution stops tinning, discard it, clean & rinse the tray, and make up a fresh solution. A cool tinning solution will usually prevent tinning so ensure the temperature of the tinning solution is at least 25ºC, but not more than 40ºC, put the bottle in hot water to warm it up.<ref name="mh" />
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* [http://www.electricstuff.co.uk/pcbs.html How to make really really good homemade PCBs] by Mike Harrison
* Wikipedia:[https://en.wikipedia.org/wiki/Comparison_of_EDA_software Comparison of EDA software]
* [
* [https://web.archive.org/web/20140517142807/http://megauk.com/ Mega Electronics] UK manufacturer and supplier of products for printed circuit board production, etc.
* [http://quinndunki.com/blondihacks/?p=835 PCB Etching Mega Redux] by Quinn Dunki, 15 February 2012
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