Just wondering if anybody has experience of gluing smooth faced birch phenolic ply face to face - it seems that standard woodworking adhesives like Titebond don't wet it properly and fall off. A web search brings up suggestions that polyurethanes work, but there's not much detail.

The chemist at a local adhesives outfit is recommending their general 30min open time general purpose liquid polyurethane structural adhesive (the stuff in cartridges is filled to make a paste) - they say they have other clients successfully bonding phenolic ply in trailers and cold stores with it. The recommendation is to sand it with 80G, then vacuum and wash the surface with cellulose thinners. A light spray of finely misted water on one surface is recommended as it's a moisture curing polyurethane - then apply the glue to one surface and assemble.

The project is a set of extension tables for my machines with top and bottom skins in 18mm phenolic birch ply, with strips of 24mm birch ply on about 175mm centres forming a honeycomb core.

Plan A was to rout 1mm off the phenolic along the bond lines using the router table, and to then use a woodworking glue. That's still an option. Trouble is one set of panels is quite large at 970x760, and the perimeter glue lines are 100mm wide. I'm a bit wary that I may not be able to very precisely maintain the depth of cut over that sort of area, and that it would risk causing an out of flat assembly. Plus it's quite a large job, and would need lots of hold downs etc made.

ian