Category Archive: Etching Tank

Jan 01

Etching Tank Heating

When the weather is too cold I can’t etch because the etching fluid freezes. So I made a heated etching tank, the heating element is recycled from an old washing machine. It consisted of 2 heating elements, a large 2Kw and a smaller 1Kw, I cut the 2Kw off so it would fit in my tank (and 3Kw would be too much). 1Kw is still a lot off power so I put a dimmer on it. To regulate the temperature I made a temperature controller with a pic16f676. The temperature sensor is a LM35 with heat shrink around it. The display is a 2x7segment display (Datasheet).

The hex file for the pic can be found here: Link.

The circuit:
Schema

The pcb (PDF):
print

etsbakverwarming
etsbakverwarming
etsbakverwarming
etsbakverwarming

Apr 20

Etching Tank Heating – Update

The triac broke because my heating element pulls almost 5A and the triac is a 4A model. Therefore I replaced it with a BT139 triac.

Jul 10

Etching Tank Heating – Update

I got a few questions about my etching tank, so I decided to take some pictures:
Etshoek

The etching tank is build from 2 ice-cream boxes:
etsbak

The bottom box is filled with water, so the etching fluid heats “au bain marie”.
etsbak

To keep the etching fluid in movement I made a stirring machine from an old walk-man and a handyvac.
roermachine
roermachine