What is a Bag Press, What Does It Do and How Does It Work? Below is a short video explaining the Bag Press: The Bag Press is a tool used by Cabinet Makers to aid in the construction of pieces with contoured or rounded surfaces, or attaching decorative veneers to contoured pieces.
The piece sits on a Former, which is in effect a timber construction created as a template of the required contour or shape.
In this case marquetry is being affixed to the concave side of a cupboard door.
The drawer front lies on the Former and is placed inside the Bag Press, under the rubber matting cover.
The cover is battened down and clamped to create an air tight seal.
Once the Cabinet Maker is sure the Press is airtight the vacuum is turned on and all air is extricated.
The force of the vacuum pulls the rubber cover tightly around the drawer front and the shaped template Former; a pressure equivalent to approximately 8 tons per square inch is achieved.
Whilst this pressure is constant, the length of time the object sits in the Bag Press for is variable dependent upon the type of construction being formed. In the case of Marquetry the Cabinet Makers will leave the piece in for about half an hour; or when actually forming the door from construction veneers would necessitate a Bag Press of about four hours.
Bag Presses are useful in ensuring that a constant, and all encompassing, force is exerted equally over all areas of the piece. Additionally no Tool Marks or scarring will be present on the piece.
Here the Cabinet Maker is removing the Marquetry Tape to reveal the inlaid work. This will be tidied up before being Traditionally French Polished.