Many 3D printing enthusiasts using PLA have explored printing directly onto glass beds, often experiencing initial success followed by a frustrating loss of adhesion. This post delves into a simple yet effective method to maintain consistent PLA adhesion on glass, potentially solving the “magic” loss issue.
Initially, printing PLA directly on a 70°C glass bed can yield good adhesion, though corner peeling might occur. To improve adhesion, frosting the glass surface is a popular technique. While standard orbital sanders may struggle, a high-speed random orbital sander with 180-grit sandpaper can effectively create a frosted surface on borosilicate glass. This frosted surface significantly enhances adhesion for a limited number of prints, around ten in this case. However, adhesion tends to diminish over time, even with thorough cleaning using alcohol or acetone.
Re-sanding the glass surface restores adhesion, suggesting a process to maintain optimal printing conditions. A recommended procedure involves wiping the glass bed with isopropyl alcohol using an abrasive Scotch-Brite pad before each print. Excess alcohol is then removed with a paper towel. This routine has proven successful in maintaining consistent adhesion and preventing adhesion failures.
This method also offers an aesthetic benefit: a matte finish on the printed part where it contacts the glass bed, which some users may prefer.
The underlying theory is that repeated printing leads to the buildup of a non-dissolvable and non-adhesive film on the glass surface. Abrasive treatment, whether through sanding or the Scotch-Brite pad, effectively removes this film, exposing the bare glass and restoring its adhesive properties. Further investigation and community input are welcomed to validate this theory and explore alternative explanations for this phenomenon.
