Brilliant! How are the needles secured to the holes in the copper?

Evo-stik Cleaner No. 3 says “Used for thinning solvent-borne adhesives based on polychloroprene rubber and, to a limited extent, nitrile rubber and polyurethane based adhesives (up to 10-15% addition). It is also used for cleaning brushes and other application equipment used with these adhesive types and as a surface cleaner prior to adhesive application.”

So that might work because you’re using a polychloroprene adhesive? I’m also not a chemist.