Improve your panel raising
Friday 04 December 2009
Anthony Bailey turns his expert eye to a tricky routing operation
If you have ever tried panel raising on the router table before, you know it can be a challenging experience when you first start. The sheer size and mass of the cutters and the amount of wood to be removed can be daunting; add to that the problems of obtaining a good result and it can seem a machining process too far. We show you how to make the job a lot easier and produce a good result.
You can't expect to create good looking panels if the boards you are using are bowed or vary in thickness. Unless your panels are very narrow, it is usual to join boards together to create the correct width. This is because the average board of timber is seldom wide enough without any flaws, and to eliminate or reduce the tendency to bow. Ensure the stock is over-length in its width and length so that once jointed, the panel will still be wide enough.
Hold one board in the vice and stand the other on it, edge to edge. There should be no gapping and boards must lie level across the faces. It's probably better that the annular rings on boards face the same way where there are just two board widths to be joined. Glued butt edges are fine if the joint is tight. You can use biscuits to keep the boards flush, but mark the limit of where they should be so the panel raising doesn't expose any biscuits.
Flat panel raisers
Your routing set-up will determine how you go about panel raising. If you have a 1/2in router and table with a decent size cutter opening, then a large, flat type panel raiser can be used. They are available in a number of different moulding designs and may have a back cutter fitted as well. This machines a limited amount off the back thus forming a tongue to fit in the surrounding frame. Remember that all these cutters must be run at low speed as the peripheral cutter speed is much higher.
Vertical panel raisers
A newer alternative is the vertical pattern panel raiser. It can be used in an 8mm collet on a smaller router and table, as it requires less power and a smaller table aperture; they can have 1/2in shanks as well. The machining procedure is different to the flat panel type as a consequence.
Ensure the fence is set in line with the cutter bearing. Use proper extraction as a lot of large chippings are generated. When vertical panel raising you must have a tall sub fence fitted that the cutter can be allowed to break through. This prevents tearout on the panel face.
Use firm pressure when making each pass. Start with the panel ends, machining cross grain, then do the long passes with the grain. Do a series of passes to depth and machine all panels at the same settings each time. Make the last pass a light cut. This is essential to avoid the panel from jumping, grain plucking and to remove any burn marks.