The bubbling action moves the etchant as well, so in a way it is a pump for the etchant. Just make sure you don't get bubbles "stuck" to your board, or you will have unetched areas. We always used the boards in a vertical arrangement, but then again we were making 25 sheets at a time... Andy "Mitchell D. Miller" on 07/17/2000 03:20:10 PM Please respond to pic microcontroller discussion list To: PICLIST@MITVMA.MIT.EDU cc: (bcc: Andrew Kunz/TDI_NOTES) Subject: Re: [EE]: PCBs using toner transfer paper > Use a fish tank bubbler. For pumping or just bubbling? -- 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