Copper Sulfate – Saline Etch for Aluminum – Test 7: Bath Strength Test (Part 2)

Name: Nick Osetek & Tessa Chambers                                 Date: 4/12/2018

Room Temperature: 68*F                                                         Humidity, etc: Dry

Experiment Title: Continuation of Bath Strength Test – 3 and 5 minute plates

Experiment Goal: To etch multiple 3 and 5 minute plates in both the original bath and the control bath. We will be monitoring each bath’s strength, and try to find a point where the bath levels out to create consistency.

Plate Material: Aluminum (5052)

Plate Preparation: We buffed each plate with fine grit steel wool, then degreased with Bon Ami and soy sauce, lastly we backed our plates with contact paper.

Evaluation of Plate Preparation: We accidentally backed the wrong side of the 3 minute plate. So we had to degrease again and back.

Etching Bath Notes: The bath’s pH seems to rise noticeably when the plates are in the bath etching. When there’s no plate in the bath the pH drops.

Time in Bath: 3 min, 5 min

After Bath Evaluation: Our original bath has stayed the same milky green colour. The control bath is starting to turn greener from use.

Removal of grounds: N/A

Inking Methods: Bone black oil based etching, 10% burnt plate oil, wiped normally

Paper Type: Hahnemuhle Copperplate

Soaking Time: 30 minutes

Press, blanket set up, and pressure: Praga press, 2 blankets, 4/9-right 5/9-left

Conclusion: Tones etched in our original bath remained consistent with our other 3 and 5-minute plates. The plates etched in the control bath were lighter compared to the past 3 and 5-minute plates.

3-minute etch comparisons from our main, original bath.

3-minute etch comparisons from our control (untouched) bath

5-minute etch comparisons from our main, original bath.






5-minute etch comparisons from our control (untouched) bath.

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