Resists for etching Aluminium with NaOH

  • Thread starter Thread starter CWatters
  • Start date Start date
Click For Summary
SUMMARY

This discussion focuses on DIY methods for etching holes in 0.3mm Aluminium sheets using 5-10% Sodium Hydroxide (NaOH) and various resist materials. Participants explored several resist options, including enamel paint, acrylic paint, Sharpie ink, vinyl masks, bitumen-based paint, and suggested alternatives like 2-part epoxy paint and high pH surface coatings. The consensus indicates that bitumen-based paint performed best, but still failed before complete dissolution of the aluminium. The need for effective resist removal methods, such as solvents or laser techniques, was also emphasized.

PREREQUISITES
  • Understanding of Sodium Hydroxide (NaOH) etching processes
  • Familiarity with various resist materials and their chemical properties
  • Knowledge of laser cutting techniques and equipment
  • Experience with solvent-based paint removal methods
NEXT STEPS
  • Research the effectiveness of 2-part Epoxy Paint for high pH applications
  • Investigate high pH surface coatings suitable for aluminium etching
  • Explore laser cutting techniques for resist removal
  • Examine alternative solvents for effective resist removal, such as Acetone and IPA
USEFUL FOR

This discussion is beneficial for DIY enthusiasts, chemists, and makers interested in aluminium etching techniques, particularly those seeking cost-effective resist solutions and methods for selective ablation using laser cutters.

CWatters
Science Advisor
Homework Helper
Gold Member
Messages
10,546
Reaction score
2,324
I'm trying to find a cheap DIY method to etch holes of various shapes through 0.3mm Aluminium sheet using 5-10% Sodium Hydroxide. The idea is to apply a resist to the Aluminium then selectively ablate it off using a diode laser cutter and then dissolve away the Aluminium using Sodium Hydroxide. By cheap I mean resists costing say £20 in small quantities.

The Internet has suggested various resists to try including...

Enamel paint (only survived seconds in the NaOH!)
Acrylic paint (only survived a short time in the NaOH)
Sharpie ink (too hard to remove it all with the laser)
Vinyl masks (adhesive dissolved by the NaOH allowing mask to come off)
Bitumen based paint (Best yet but finally came off before all the Aluminium was dissolved)
Nail varnish (not tried yet)
2 part Epoxy Paint (not tried yet)
Kapton tape with Acrylic adhesive (not sourced yet)

I also need to remove the resist using a solvent of some sort (Acetone, IPA, gasoline etc) although I suppose I could also laser it off.

So can any chemists suggest other resists or which to try next?

The 2 part Epoxy Paint is probably my best bet but it's not very convenient and hard to find in small quantities. 1K Epoxy paint in a can apparently isn't good enough.

Any suggestions?
 
Chemistry news on Phys.org
I am not a chemist, but if it was my project I would try a paint intended for high pH surfaces (such as masonry).
Such a coating might be hard on the aluminum, but I would hope that it lasts long enough for the NaOH and wash. I would think it would survive the NaOH itself without a problem.

As an example: https://www.millerpaint.com/product/ph-surfacer-interior-exterior-primer-2/
 
Thanks Scott, great suggestion.
 
Why are you resorting to chemical means rather than simply poking holes? 0.3 mm is just aluminium foil?
 

Similar threads

Electronics Using photos for project front panel labels/artwork
  • · Replies 30 ·
2
Replies
30
Views
6K