Advanced Router Techniques for Woodworkers

The router can do far more than round over an edge or cut a groove.

When I first started using one nearly 50 years ago, those were about the only jobs I knew how to do. Since then, it has become one of the most useful and versatile tools in my shop, especially when paired with a router table.

With the right bit or a simple shop-made jig, a router can cut circles, flatten slabs, reproduce curved parts from a pattern, shape architectural molding, and even hollow out wooden trays. Many of these techniques can replace larger or more specialized machines, which makes them especially valuable in a smaller workshop.

The key is learning how to control the router accurately and safely. In this article, we’ll look at several advanced techniques that can help you get much more from a tool you may already own.

1. Architectural Trim

Making your own architectural trim is one of the most practical uses for a router table.

Architectural trim includes baseboards, window and door casing, chair rails, crown molding, and other decorative details used throughout a home. The wider and more detailed the profile, the more expensive that trim tends to be, especially when it is made from solid wood rather than paint-grade material or molded plastic.

A router table allows you to produce your own profiles from ordinary lumber or leftover material. Besides saving money, this gives you control over the wood species, width, shape, and finish.

I recently used this approach while remodeling a family room. One wall was covered with solid tongue-and-groove acacia flooring, and I had enough material left over to make matching baseboard. By routing the leftover flooring myself, I could carry the same color and grain around the room rather than trying to find commercial trim that looked close.

Choosing the Material

You can make trim from hardwood, softwood, or suitable reclaimed stock.

Clear pine is a good option when the trim will be painted. Look for straight boards with as few knots as possible because large knots can tear out or interfere with the routed profile. No. 1 common lumber will generally give you better results than lower grades.

Hardwoods are a good choice for stained or clear-finished trim. They cost more, but making the molding yourself can still be considerably cheaper than buying finished hardwood trim.

The stock should be straight, flat, and consistent in thickness. Any twist or bow will make it harder to hold the board firmly against the router table and fence.

Use a Router Table

Architectural molding should be cut on a router table rather than with a handheld router.

The workpiece is usually long and narrow, and the molding bit may remove a substantial amount of material. A table gives you a stable cutting surface and lets you guide the board against a fence while the bit remains fixed.

Table size matters too. A small router table can work for short pieces, but longer boards become difficult to balance. When part of the board hangs unsupported, it can lift or tilt as it enters or leaves the cut.

Support the entire length with a large tabletop, infeed and outfeed supports, or roller stands. The board must remain flat throughout the pass if you want a consistent profile from end to end.

A tall fence is also helpful, especially when working with wide baseboard or casing. It gives the board more surface to register against and makes it easier to keep the stock upright.

Cutting the Profile Upside Down

Most architectural molding is routed with its finished face pointing down.

The flat back of the molding will eventually sit against the wall, while the decorative face is shaped by the bit below the router table. Once the profile is complete, the board is flipped over for installation.

Before routing the full batch, make a short test piece. Use it to adjust the bit height and fence position until the profile looks right. Save that test piece so you can use it as a setup gauge later if you need to make more matching trim.

Make Several Light Passes

Large molding profiles should rarely be cut to full depth in one pass.

Trying to remove too much material at once places a heavy load on the router and increases the chance of tear-out, burning, chatter, or loss of control. It can also make the board much harder to keep against the fence.

Start with the fence positioned so only a small portion of the bit contacts the wood. Make the first pass, move the fence back slightly, and repeat until the full profile is reached.

Two or three lighter passes are usually much easier to control than one aggressive cut. The exact number depends on the size of the bit, the hardness of the wood, and the amount of material being removed.

The final pass should be light. Its job is to complete the shape and clean up the surface rather than remove a large amount of wood.

Maintain Pressure in Two Directions

Consistent trim depends on holding the stock firmly in two directions:

●     Down against the table

●     Sideways against the fence

Downward pressure prevents the board from lifting and creating a wavy profile. Sideways pressure keeps the depth of the cut consistent.

As the profile becomes deeper, the board may have less flat surface remaining against the fence. Adjust your hand position so you are pressing on an area that still provides solid contact.

Featherboards can help maintain pressure, especially when producing several identical lengths. They also let you concentrate more on feeding the stock at a steady rate.

After routing, the profile should need only light sanding before finishing.

Adding Decorative Corner Blocks

The same molding bit can also be used to make matching corner blocks.

A corner block is a square piece installed where two lengths of trim meet. Instead of mitering the molding together at the corner, each length can be cut square and butted against the block.

This makes installation easier and adds a decorative detail. Corner blocks are commonly used with baseboard, door casing, and crown molding.

Because these pieces are short, they should never be held close to the bit with bare hands. Secure the block in a right-angle carrier or another shop-made holding jig that keeps it square while placing your hands safely away from the cutter.

Choose the block size carefully. It should be slightly wider or more prominent than the molding without overwhelming it. Make one sample first and hold it in position before producing the rest.

The ability to make both the trim and its matching corner details is one of the main advantages of producing architectural molding yourself. With a router table, an appropriate profile bit, and properly prepared stock, you can create custom woodwork that would be expensive to buy ready-made.

2. Circle Cutting

Cutting a clean, accurate circle can be surprisingly difficult with a jigsaw or bandsaw. Even when you follow the layout line carefully, the edge usually needs quite a bit of sanding before it looks truly round.

A router fitted to a simple circle-cutting jig gives a much more consistent result. The jig works like a compass: the router stays a fixed distance from a pivot point and travels around it, creating a circle with a precise radius.

Making a Simple Circle-Cutting Jig

A basic jig can be made from scrap plywood or another flat, stable material.

Cut an opening or build a small cradle that holds the router securely. Then add a pivot point farther down the jig. A nail, screw, or removable pin can serve as the pivot.

The distance from the center of the router bit to the pivot determines the circle’s radius. For example, if those two points are 10 inches apart, the jig will cut a circle approximately 20 inches in diameter.

A 1/4-inch straight bit works well for many circle-cutting jobs. The router should sit firmly in the jig without shifting. A simple jig can be held in place by hand, although clamps, retaining blocks, or a ledge around the router base provide better security.

Making the Jig Adjustable

For repeated use, it is worth adding an adjustable pivot.

A sliding block or slot allows the pivot pin to move closer to or farther from the router. Once the desired radius is set, lock the pivot securely so it cannot shift during the cut.

An adjustable jig makes it possible to cut many different circle sizes without building a new guide each time. The maximum circle size is determined by the length of the jig. A longer version can easily handle tabletops and other larger projects.

The jig does not have to look elaborate. As long as it holds the router a fixed distance from the pivot and moves smoothly, it can produce an accurate circle.

Preparing the Workpiece

Mark the center of the circle clearly and place the pivot pin at that point.

Because the router bit must cut completely through the workpiece, place a sacrificial board underneath it. This protects the workbench and supports the cut as the circle is completed.

Secure both the workpiece and the backing board so neither can move. The center section and the surrounding waste may shift when the cut is completed, so the setup should support both pieces.

When possible, remove most of the waste first with a jigsaw or bandsaw, leaving a small amount outside the finished circle. The router then has less material to remove and can concentrate on creating the final edge.

Cutting the Circle

Do not attempt to cut through thick stock in one pass.

Set the router for a shallow cut and make a complete trip around the pivot. Lower the bit slightly and repeat until the cut passes through the workpiece.

Several shallow passes are easier on the bit and router, and they reduce the chances of burning, tear-out, or losing control.

Keep steady pressure on the jig so the pivot remains firmly seated. Move at a controlled pace and avoid forcing the router through the wood. Once the cut is complete, the edge should require only light sanding.

3. Planing With a Router

A router can also flatten slabs, tabletops, butcher-block glue-ups, and other workpieces that are too large or irregular to fit through a thickness planer.

This is especially useful for live-edge slabs and river tables. A typical dining table may be 30 inches wide and 6 feet long, while many home-shop planers have a capacity of only 12 to 13 inches.

Instead of feeding the workpiece through a machine, the router travels across the surface in a sled or gantry.

How a Router Planing Sled Works

A router planing setup has two main parts:

1. A pair of level rails running along the sides of the workpiece
2. A bridge or sled that spans those rails and holds the router

The sled moves along the length of the workpiece while the router slides from side to side across the bridge. Together, those two movements allow the bit to reach the entire surface.

Commercial systems use metal rails and ball-bearing slides. They are accurate and convenient, particularly when this type of work is done regularly.

A shop-made wooden gantry can work well too. If the workbench itself is flat, it may even serve as the supporting surface for a simple sled. The important point is that the router moves in a flat, controlled plane above the workpiece.

Level the Gantry Carefully

The rails or supporting surface must be level with one another in both directions.

If one rail is higher than the other, the router will cut the surface at an angle. If the sled twists or rocks, the bit may leave gouges or uneven tracks.

Take time to check the setup from side to side and from end to end. A basic wooden gantry can produce excellent results, but only when it is built and positioned carefully.

The router sled should also move freely without excessive play. It needs enough clearance to slide without binding, but not so much that the router can tilt.

Choosing the Router and Bit

A plunge router is particularly useful because the cutting depth can be adjusted between passes without removing the router from the sled.

Use a bit designed for slab flattening or spoilboard surfacing. These bits have a wide cutting diameter and remove a broad strip of material with each pass. A 2-inch bit can cover the surface efficiently, but its size also creates substantial cutting forces.

Larger bits should generally be used at a lower router speed. Check the bit manufacturer’s recommended speed range and do not assume that full speed is appropriate.

A bit with a 1/2-inch shank is preferable for this type of heavy work because it provides more strength and stability than a smaller shank.

Use an Extension Correctly

Some sled designs require the bit to reach farther below the router base than it normally would.

Do not solve that problem by barely inserting the bit into the collet. The shank needs proper engagement to remain secure. Running a large surfacing bit with too little shank inside the collet can allow it to slip, bend, or come loose.

Use a purpose-made collet or shaft extension when additional reach is necessary. Install both the extension and the bit according to their instructions, making sure all connections are fully seated and tightened.

Secure the Workpiece

The workpiece must not move, rock, or vibrate while it is being flattened.

Irregular slabs and crosscut rounds often need more than ordinary clamps. Use stop blocks, bench dogs, wedges, hold-down clamps, or a combination of them to lock the wood in place.

Wedges are especially helpful under uneven pieces because they prevent rocking. Any supporting wedges should be positioned below the final cutting surface so the router cannot contact them.

Before starting, push firmly on several areas of the workpiece. If it moves at all, improve the clamping setup.

Take Shallow Passes

A router sled removes material progressively.

Begin with the bit just low enough to contact the highest point on the workpiece. Move across the surface in overlapping passes, then lower the router slightly and repeat.

An 1/8-inch depth of cut is a good target for most passes. Up to 1/4 inch may be possible in some situations, but shallower cuts are easier on the router and leave a better surface.

Irregular slabs may require several passes before the bit reaches every part of the face. The first passes will touch only the highest areas. As the router is lowered, more of the surface gradually comes into the same plane.

Patience matters here. Trying to remove too much material at once increases vibration, heat, burning, tear-out, and the risk of damaging the workpiece.

Control the Cutting Direction

A wide planing bit should not be buried completely in the wood during every pass.

Overlap each cut so only part of the bit’s diameter is removing new material. This reduces the load on the router and makes the cut easier to control.

Pay attention to the direction of bit rotation as well. Feed the router so the cutting action does not pull the sled unexpectedly across the workpiece.

Move steadily across the surface in one cutting direction, return without taking another full-width cut, then begin the next overlapping pass.

Flattening Epoxy and River Tables

The same process works for river tables, but epoxy should be cut conservatively.

Take very light passes to reduce heat and avoid chipping or cracking the epoxy. A sharp surfacing bit and slower, steady feed rate will generally leave a cleaner result than an aggressive cut.

Make sure the wood and epoxy are both fully cured and securely supported before routing.

Expect to Sand Afterwards

A router planing sled produces a flat surface, but it does not produce a finish-ready surface.

The bit may leave shallow tracks, ridges, or occasional burn marks. These are normal and can be removed with sanding after the flattening is complete.

The router’s job is to establish a level plane. Sanding then removes the machining marks and prepares the surface for finishing.

Once the first face is flat, turn the workpiece over, secure it again, and repeat the process on the opposite side. Because the flattened face now provides a stable reference, the second side is usually easier to set up.

A router sled takes time, but it is much faster and more reliable than trying to flatten a large tabletop with a belt sander. It also expands the size and type of projects you can handle without buying an industrial-width planer.

4. Pattern Cutting

Pattern cutting is one of the best ways to make several wooden parts with exactly the same shape.

Suppose you are building a set of dining chairs with a curved upper rail. Cutting every rail separately with a jigsaw or bandsaw would make it difficult to produce identical curves. Even small differences become noticeable when the finished chairs are placed together.

Instead, you can perfect the shape once in a reusable template and let the router reproduce it on every workpiece.

Pattern cutting takes extra preparation, so it usually makes the most sense when producing multiple parts or when making an item you expect to build again. For a single simple curve, making a dedicated template may take longer than shaping the part directly.

Make an Accurate Template

Templates are commonly made from 1/4-inch or 1/2-inch plywood, MDF, or another stable sheet material.

The template determines the final shape of every part, so take time to make it accurate. Smooth out bumps, flat spots, and saw marks before using it. Any defect left in the template will be copied into the workpiece.

The edge should also be square and smooth enough for the router bit’s bearing to follow without catching.

Once the template is finished, place it on the workpiece and trace its outline.

Rough-Cut the Workpiece First

A pattern bit is intended to trim the wood to its final shape, not remove all the waste from a full board.

Use a bandsaw, scroll saw, or jigsaw to rough-cut the workpiece first. Stay about 1/8 inch outside the layout line when possible. Leaving up to 1/4 inch can still work, but it gives the router more material to remove.

There is no need to follow the line perfectly during this step. The router and template will establish the final shape.

Removing most of the waste beforehand reduces the load on the router, lowers the chance of tear-out, and gives you better control.

Choose the Right Pattern Bit

A pattern bit is a straight-cutting router bit with a guide bearing that matches the diameter of the cutting edges.

As the bearing follows the template, the cutters remove any wood extending beyond it. This produces a workpiece that closely matches the template.

Pattern bits come in different cutting lengths, so choose one suited to the thickness of the material. The bearing must ride completely against the template while the cutting edges cover the full thickness of the wood being trimmed.

If the bit is too short, it may leave a small ridge along one edge. That ridge can often be removed with another pass after adjusting the router depth, provided the bearing can still follow the template safely.

A full-size router is generally preferable for larger parts and heavier cuts. A trim router can handle lighter pattern work when the remaining waste is minimal.

Attach the Template Securely

Double-sided woodworking tape works well for securing the template to the workpiece.

Use enough tape to keep the template from shifting, then press the two pieces together firmly. The surface should be clean and free of dust so the adhesive can grip properly.

For larger or more demanding cuts, add screws in waste areas or use another mechanical fastening method. A moving template will ruin the workpiece almost immediately because the router will follow the shifted edge.

Secure the workpiece separately to the bench. Do not rely on the tape holding the template to also hold the entire assembly in place.

Place a sacrificial board beneath the workpiece if the router bit will extend slightly below it. This protects the workbench and gives you room to set the bit for the full thickness of the cut.

Rout to the Finished Shape

Set the router depth so the bearing rides against the template while the cutters contact only the workpiece.

Guide the router steadily around the shape without forcing it. If the remaining waste is heavy, remove it in more than one pass rather than burying the full cutter in the wood.

Curved grain can sometimes tear out as the router travels around the part. Taking light cuts and slowing down in difficult areas helps. In some situations, you may need to approach a section from the opposite direction very carefully to avoid lifting the grain.

Once the routing is complete, separate the template from the workpiece. The edge may still need light sanding, but it should be much smoother and more consistent than a shape cut entirely by saw.

As long as the template remains undamaged, you can use it to make as many matching parts as needed.

5. Bowl Cutting

Bowl cutting is closely related to pattern cutting, but instead of trimming the outside of a workpiece, the router follows an internal template to hollow out the center.

The result is usually a shallow wooden bowl or tray rather than a deep vessel. This technique works well for candy dishes, serving trays, relish trays, snack trays, and divided platters.

The shape can be round, oval, rectangular, or divided into several compartments. The main limitation is not the router itself, but the template you are able to design and make.

Use a Bowl-Cutting Bit

A bowl-cutting bit resembles a pattern bit, but its bottom corners are rounded.

Those rounded cutting edges leave a smooth transition between the bottom and sides of the recess. A square-bottomed straight bit would leave sharp internal corners and would be more likely to dig into the workpiece.

Bowl bits are available in several diameters. A wider bit removes material faster and leaves a broader, smoother bottom, but it also creates more cutting force.

The guide bearing must be the same diameter as the cutting portion because it follows the internal edge of the template and controls the finished shape.

Add a Larger Router Base

A standard router base may be too small for bowl cutting.

As the recess becomes wider, the router base must span the opening without dropping into it. If the router tips, the bit can gouge the bottom or cut completely through the workpiece.

A larger auxiliary base solves that problem. It can be made from clear polycarbonate so you retain as much visibility as possible. Polycarbonate is generally preferable to acrylic because it is less brittle and less likely to chip while being drilled or cut.

A base around 1/4 inch thick is usually adequate, provided it remains stiff and is attached securely to the router.

Make the base large enough to bridge the widest opening in the template. This is particularly important when cutting a divided tray with several compartments.

Build and Secure the Internal Template

The template defines the outside wall of the recess.

It must be thick enough for the guide bearing to follow reliably and strong enough to withstand repeated contact. Plywood or MDF can work well, as long as the inside edge is smooth and free of defects.

Secure the template very firmly to the workpiece. Double-sided tape alone may be adequate for a small, shallow cut, but screws provide additional security. Place them in areas that will later be removed when the outside shape is cut.

I have ruined workpieces by trusting a template that was not attached well enough. Once the template shifts, the router immediately cuts beyond the intended shape.

The workpiece itself must also be clamped securely to the bench. Use bench dogs, hold-downs, stop blocks, or other clamps that prevent movement in every direction.

Cut the Inside Before the Outside

When making a tray or shallow bowl, hollow the interior before cutting the final outside shape.

The surrounding waste material helps support the router’s enlarged base. If the outside is cut first, there may not be enough material left around the recess to keep the router level.

Once the interior is complete, you can cut the outside with another template, a bandsaw, or a table saw, depending on the shape you want.

Remove Most of the Waste First

Routing the entire recess with a bowl bit takes time and creates a tremendous amount of sawdust.

A faster method is to remove most of the material with a Forstner bit before using the router. Drill overlapping holes while staying safely above the final depth and away from the template walls.

The Forstner bit handles the bulk removal efficiently. The bowl bit then cleans up the bottom, establishes the final depth, and brings the walls to the exact template shape.

Do not drill so deeply that the center point or cutting rim passes through the bottom.

Work Down in Shallow Stages

Set the router for a shallow first pass and move it throughout the opening while keeping the bearing against the template where appropriate.

Lower the bit gradually for each following pass. Do not attempt to reach full depth at once. Light cuts are easier to control and place less strain on the router, bit, and template.

A plunge router makes these depth changes much easier.

Visibility will become limited once the cut begins. Even with a clear base, the recess quickly fills with chips and dust. Stop periodically, allow the bit to come to a complete halt, and clear the waste before continuing.

Dust extraction helps, but bowl routing still produces a substantial amount of debris. Wear eye and hearing protection, and keep your face away from the path of flying chips.

Reaching Greater Depths Safely

As the recess gets deeper, the router may reach the limit of its plunge travel.

Do not extend the bit by leaving only a small portion of its shank inside the collet. A poorly seated bit can slip, bend, or come loose.

Use a proper router-bit extension when additional reach is necessary. Begin without it when possible, then install it only after the router can no longer reach the required depth safely.

Make sure the bit and extension are fully seated and tightened correctly.

How deep you can cut depends on the router, bit, extension, template, and workpiece thickness. In most cases, this method is best suited to shallow serving dishes rather than deep cereal or soup bowls.

For example, a recess about 7/8 inch deep in 1-inch stock leaves only around 1/8 inch of material at the bottom. That can work for a serving tray, but it leaves very little margin for error. Measure carefully and stop before the bottom becomes too thin.

Shape and Finish the Tray

Once the recess is complete, remove the template and inspect the surface.

Some burn marks or routing tracks are normal. Sanding the inside takes patience, particularly in divided trays, but the rounded corners left by the bowl bit make the job easier.

The upper inside edges can be softened with a small round-over bit. After cutting the outside shape, round over or ease those edges as well so the tray feels comfortable to carry and has no sharp corners.

The final layout should suit the intended use. A relish tray may need only three sections, while a vegetable tray could use several compartments surrounding a central bowl for dip.

That is where bowl cutting becomes especially interesting. Once you understand the template and router setup, you can create serving pieces in almost any arrangement you can design.