>Dear Dave, > Can I use the prepared KI,I2,DI water (4:1:40) solution for >gold etchant after 20 days because I preserved it in a glass bottle. > >Regards >Hare Krishna > Hare Krishna, You can use the solution for more than 20 days unless the bottle was opened. The solution will be diluted after few cycles which results in nothing but some more etching time. I generally use the solution for like 4 - 6 months. Regards, Aasutosh Dave _________________________________________________________________ Get a FREE online computer virus scan from McAfee when you click here. http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963