--- Jinx wrote:> Debbie, I'm not a big fan of long cold etch times, mostly because the > etchant > has time to get under etch-resist and make breaks or fuzzy tracks > > The simplest fix is a hot water jacket. Etch time will be 6-7 minutes > > http://home.clear.net.nz/pages/joecolquitt/0makepcb.html That's true - a long etch is no good for fine tracks. I tend to keep them >1.2mm width if possible. Re the other posts, about FeCl3's hazards, I had a similar disaster with rust one time. It was a REALLY hot day, like ~45C, and I left the stuff in an open container. When I got back, there was rust on everything nearby that was made of steel. I think what happens is the FeCl3/water mix slowly releases HCl when hot. Bad news => good ventilation is indicated? The grot that forms on storage is probably Fe(OH)3. If you acidify the solution with HCl, it should disappear. One hazard that med. page did not mention is if you drop aluminium into conc FeCl3, the reaction is HIGHLY exothermic and you'll have boiling fizzy etchant splattering everywhere in short order. If you do electronics metalwork, there's usually no shortage of Al offcuts around the place ... Debbie :) Find local movie times and trailers on Yahoo! Movies. http://au.movies.yahoo.com -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist