I know this is a little late but I just joined the forum. The best adhesive I have found for PETG is Scigrip 16. I got it at Amazon: https://www.amazon.com/gp/product/B003HNFLMY/ref=od_aui_detailpages00?ie=UTF8&psc=1 Runny, can be messy, but it welds the parts together. I have not tried it on PL...