When using self-adhesive outdoor adhesives, there are cheaper alternatives to Gorilla glue. But I don't think any of them can match the holding power and strength of this polyurethane adhesive. And not much is enough, so it's well worth the extra cost for Gorilla Glue. The only downside to GG is that it foams from the seam, but this is easily removed AFTER drying with a chisel or scraper, or even by sanding. Oh yes, and it can be "tough as a bear" (or in this case, "tough as a gorilla") to peel off your fingers even after drying. But despite all that, it's worth it for its holding power and the fact that it's 100% waterproof once it's cured.
SCIGRIP 10799 3 Acrylic Solvent Cement, Low-VOC, Water-Thin And Very Fast Setting, Clear, 1/4 Pint (4 Fl Oz)
5 Review
Enhanced Conductivity Dispensers by MG Chemicals
4 Review
π¨ Extreme Construction Adhesive: Liquid Nails
7 Review
π§ Liquid Nails LN 903 Industrial Construction Adhesive: High-Quality Tapes, Adhesives & Sealants
5 Review