>From: "starsnstripes_2003" <bwatson@...> >Reply-To: Homebrew_PCBs@yahoogroups.com >To: Homebrew_PCBs@yahoogroups.com >Subject: [Homebrew_PCBs] Poor Man's Drill Press >Date: Sun, 20 Jul 2003 03:49:00 -0000 [deleted] Congratulations! >> >Developer: Lewis Red Devil Lye purchased from Albertson's July, >2003. Mixed at approx 6g per Liter? I use about 10 g/litre. No brushing needed. It depends on the resist material. >I calculated it to be 1 Tsp per Quart. Used Lowe's 1" foam brush >lightly. Worked great. > >Etchant: I'm using 34% HCL from Lowe's Garden Center and 3% Hydrogen >Peroxide from Albertson's mixed 1:1. >I used no water, because most recipes call for stronger Peroxide. >This solution seems to work if you use it right away. >If you let it stand for a while it seems to be "die" or slow down. >Why is this? >I Really could use some input on this Etchant mix. Does the HCL/H2O2 >mix always die soon after mixing? >Does it only work while the solution is still bubbling? Yes, the H2O2 gets converted to H2O and O2 very quickly. The reaction needs the free oxygen to work properly. Keep adding H2O2 each time you do some etching and you will eventually end up with a reasonable concentration of cupric chloride. That will work without the H2O2, although you will have to add a little from time to time, to convert the cuprous to cupric chloride. You'll also need to add some HCl, occasionally. You'll need to heat the cupric chloride for it to work - I use two containers, the outer one is filled with hot water. Leon -- Leon Heller, G1HSM Tel: +44 1424 423947 Email:leon_heller@... My web page: http://www.geocities.com/leon_heller _________________________________________________________________ On the move? Get Hotmail on your mobile phone http://www.msn.co.uk/msnmobile
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Re: [Homebrew_PCBs] Poor Man's Drill Press
2003-07-20 by Leon Heller