This project is to fit a painting into a carved antique frame, using a flat water gilded slip with a bevelled inner edge, which is only 3mm thick. It started as a 9mm thick slip frame (no rebate), a cabinet maker friend put this through an industrial planer until the required 3mm thickness is reached. This is far to thin to join together securely on the underpinner so a backing frame is made from a deep box frame moulding. This backing frame is constructed with simple butt joints joined with dovetail keys, I could have saved alot of time and just mitred the backing frame and joined on the underpinner, but the butt joint will give much more stability and strength to the mitred slip that will be on top. This will help to reduce the mitres opening up over time. So the slip frame was then glued with polyurethane adhesive and clamped to the backing frame. Once the glue was set the excess outside edges were cut off on a table saw, to fit the rebate of the antique frame.
