The Framers Forum

really bad joins on polycore molding.
can`t seem to work out why this is happening ,
Could it be blunt morso blades causing a bad cut.
Or could it be the underpinner?
anyone had this issue before.
thanks.

That's really not that surprising, but the good news is that there a simple solution to the problem. The wedges are displacing some of the core material as they displace material to create room for them penetrating into the moulding. A rebate clamp that reall strongly pull both bits of moulding together and won't let the mouldings pull apart, will mean that core material won't be able the be displaced in quite the same way and will stop the gap from forming.

The other solution is to super glue the two pieces of moulding and let the super glue set, before joining them on the underpinner. You need to glue them together with a reasonable contact area, so that the moulding pieces cannot separate as the wedges go in. Needless to say keep the applied super glue away from the external presentation surfaces of the moulding. If super glue gets onto the external faces of the moulding it's a real big problem.

been using this molding for a while. and its only started happening . So im bit puzzled.
gona try new blades tomorrow, to see if that fixes it .

Check for glue build up on the underpinner.