I build my own cores using MDF with a solid wood edge to allow me to create profiles on my tops. The problem I am having is that once my tops are sanded and clear coated, a shadow line appears where my MDF attaches to my natural wood. What is causing this problem, and how can I correct it?
From contributor D:
This is called telegraphing and is caused by the substrate and solids moving at different rates, in response to changes in relative humidity.
Minimize the swings of humidity the tops are exposed to. There is only so much you can do here, but it will help. Crossbands on both faces (to preserve balance) will minimize the telegraphing. The thicker, the better, within reason. Another strategy is to add the solid wood flush to the veneer face, with a slight V-joint. Any difference will get lost in the V.