How do those of you who use liquid tin dispose of the leftover once you have coated your board? I'm no chemist but I suppose mixing it in my container of used ferric chloride isn't a good idea.
How much are you talking about? If it's just a few ounces I wouldn't think twice about pouring it in an old plastic soda bottle diluting with some water and tossing it. If more, I would look at the manufacturers recommendation for disposal or asking if there is a neutralizing agent that you can add to it.
I'd just collect it in a separate container (old soda bottle should do the trick for that stuff) and dispose that at a local site for hazardous wastes once the container is full. You can however, easily use the solution more than once. at least I could with the one I made myself, but that also degraded on its own. No idea about the commercial stuff.
I wouldn't try to mix it with the iron chloride. It shouldn't react heavily, as tin and iron are both in higher oxidation states, +3 and +2 iirc, so there's nothing for the tin to oxidize in order to reduce itself to the metallic 0 state. However, as it's used FeCl3 solution, who knows what gunk is in there...
On the other hand, we just pour any aqueous waste together in a big container all the time and nothing happens. We do neutralize pH prior to that though.
Thanks guys. It's just a tiny bit to make a face plate with. I'll get a clean bottle and attempt to reclaim it for reuse.
If i'm not sure i do like Felix recommends and cart those things to the hazardous waste handlers.
Mix with kitty litter and toss?
dave
You can re-use Liquid Tin for a long time. It will start to pick up crud and sediment with each use but these will settle to the bottom of the container over a few days. So, don't shake when re-using--just pour from the top. I wonder if you could try using a coffee filter on that, though. Might help get rid of some of the containment.
Even when I was hand-making the MBP PCBs a single bottle of LT would last for a few months. I just kept re-using the stuff. The secret is to do a very light sanding on the tinned board with 0000 Steel Wool afterward then clean with Acetone.
The township of where I lives website has dates for hazardous waste pick up. I'll reclaim the tin for awhile. When I get rid of my ferric chloride, I'll hand them some liquid tin too.
Thanks for the replies guys much appreciated.