The crystals unmixed will keep indefinitely. Once dissolved and the
cayalyst added, it will begin to slowly weaken. I have mixed a portion
of solution and did a small board. Left it in the tray for a few weeks.
Came back and heated it and did two more boards. I don't think it would
last too much longer than that. Although once I let the solution dry up
into crystals again and I just added water and it still etched a board
when heated. It doesn't stain or smell. It looks like blue Windex when
used up. I just pour it into a 5 gallon bucket and let it dry into
crystals. Once I get a lot of it (I mean a lot, which takes years), I
put it into a plastic bag and take it down to the landfill where they
have a hazardous waste day for disposal.
See my webpage.
Rick
http://www.pic101.com/pcbmdgolfbum wrote:
> Rick
>
> Thanks for the quick response. Any benefits? FeCl is a big stainer
> but keeps well. Any info on SP like shelflife, disposal issues,
> staining, smell?
>
> tnx
> jtm
>
>