Thank you mike.
The aluminium heat sink has it's fins nailed through the wood into a cut down cupboard door which was covered in melamine. The wood runs along the top of the fins making for an unmoveable wall.
The angle is exactly 90 degrees and the parts can be pushed up tight and held for the first 5 seconds of glueing. Inside corners can be glued using the acute edge of the wall and around the side.
Sometimes the 'Plastiweld' runs through the gap and sticks the whole lot to the aluminium. When dry, I find it cracks apart easy with a dulled kitchen knife down the back.
All in all, a great little unit.
ken