I get minimum etch time by using these tricks: 1. I use a hair dryer to heat the etchant. My etch tank has a "secondary containment" tank that surrounds it, made from a plastic laundry tub with a lid. I stick a hair dryer through a hole in the side of the laundry tub. This gets the inside to about 130F 2. I bubble air through the etchant. I have a piece of fiberglass hose (originally used for electrical insulation) hot glued to the bottom of the etch tank. I run 15-20PSI compressed air onto the hose, turning the etch tank into a seething froth. With this arrangement, you really need the secondary containment tank because it make a lot of mess. Mind you, this may sound funky but it is not a hobby arrangement - just low budget! -- Lawrence -----Original Message----- From: Mitchell D. Miller To: PICLIST@MITVMA.MIT.EDU Date: Monday, July 17, 2000 11:47 AM Subject: Re: [EE]: PCBs using toner transfer paper >> I have to say the best advice I've received so far with respect to etching >> circuit boards came from Tony Nixon. I heat my etchant by putting my >etching >> tray in a sink of warm water, > >I agree. I rearranged my lab over the weekend, and did another board >yesterday. I now have a utility sink available (fiberglass). I filled the >sink with about 1" of hot water, placed my etchant container in the water, >and filled it with etchant. > >I also used the "upside down" technique someone previously mentioned. By >placing the board (single sided, 1oz, FR4) face down on top of the etchant, >I could actually see where the copper had been removed. > >The combination of both reduced my etching time to about 5 minutes. > >-- Mitch > >-- >http://www.piclist.com hint: PICList Posts must start with ONE topic: >[PIC]: PIC only [EE]: engineering [OT]: off topic [AD]: advertisements -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]: PIC only [EE]: engineering [OT]: off topic [AD]: advertisements