There are certain woodworking skills that unlock new possibilities once you know about them. It’s like jumping through a pipe and starting a side quest in a video game. Template routing is one of those skills.
Template routing comes up in the torpedo level, play station, and kitchen chair — just from this issue. The technique is simple in concept: create a template of the shape you require, then use a router and a special bit to recreate the shape of the template onto a workpiece.
Template routing is usually associated with making complex profiles or when you need multiple copies. However, there are good reasons to employ this technique for everyday tasks. The space constraints of a project article allow for a summary of the process. From time to time, it pays to take a deeper dive in order to refine your technique and improve the results you get.
REASONS IT WORKS.
One of the reasons we turn to it so often concerns consistency. Taking the time to make a template means the completed part will turn out the way you want. It functions almost like a practice round.
Personally, I like how the process breaks down a task into distinct steps. I focus on each one in order. It keeps me from rushing through an operation or pushing a tool to do a task it doesn’t excel at.
Template routing involves several ingredients. So we’ll look at each one individually then combine them into a workflow.
TRIMMING BITS
Let’s start at the working end — the bits. Template routing requires a bit that can follow the edge of a template and cut away the overhanging waste material. There are several types of bit to choose from.
GOOD.
Pattern bits, flush-trim bits, and double bearing flush-trim bits allow you to create multiple, identical parts. Inexpensive bits feature straight, carbide-tipped cutting edges.
The three bits shown above are the standards. They’re available from a large number of manufacturers. A pattern bit looks like a straight bit with a bearing on the shank end. This type is ideal for plunge cutting recessed elements.
A bit with a bearing on the tip signifies a flush-trim bit. It’s the workhorse. This one requires that the template be located on the opposite side of the workpiece from the router. Double bearing bits offer an upgrade to a typical flush-trim bit.
You can affix the template to either side of the workpiece. On heavily curved parts, you can even change which face you rout from in order to prevent cutting against the grain.
BETTER.
Typical bits have straight cutting edges that can leave noticeable ripples or rough edges. To counter that, some bit makers have incorporated angled cutting flutes into their trimming bits.
Woodline’s trimming bits featured angled cutting flutes to create a smooth surface. The opposing angles prevent tearout on the faces of a workpiece.
The two bits shown in the upper right show how Woodline addresses this. Here the carbide flutes angle in opposing directions. Downcutting flutes on the shank end and upcutting flutes near the tip eliminate chipout on each face of the workpiece.
BEST.
For the ultimate in smooth surfaces, you need to go beyond angled cutting flutes. Spiral cutting edges create less impact at the point of cut.
Woodpeckers’ Ultra-Shear bits are made from a single piece of carbide. The complex machining results in a stable, smooth-cutting bit.
The bits at right are made by Woodpeckers. They’re milled from solid carbide blanks. This allows for a refined cutting geometry that cuts smooth on hardwood end grain, and lasts longer when cutting plywood and MDF.
You can see these bits also include the compression cutting design that includes both upcut and downcutting flutes. The solid-carbide construction also allows for a plunge-cutting pattern bit for deep mortises (up to 2") or pockets.
UNDERSTANDING TEMPLATES
A flush-trimming router bit is one part of the template-routing equation. The other part is the template. It provides the bit guidance on what the completed part needs to look like.
That’s the key we’ll focus on now. Whatever is on the template will be duplicated on the workpiece. In practical terms, this means it’s worth taking time to make the template just right. Otherwise you could end up copying a flaw onto the workpiece (over and over) that you’ll have to remove later on.
MAKE IT EASY.
As important as the template is, its purpose is in service to the project. This means the template doesn’t have to be fancy. You want to select a material that’s inexpensive and easy to shape. This allows you to dial in the details on the template with confidence. And if you make a mistake, no harm; just start over.
1⁄2" MDF is a low-cost, easy-to-shape material for creating templates. The light surface allows you to see lines clearly. Interior curves are shaped with drill bits. Files and rasps permit fine details.
There are two materials that fit these criteria: hardboard and MDF. They are available in flat, smooth sheets in a range of sizes. Both are made up of fine particles that can be formed into smooth surfaces. So you don’t have to worry about grain direction, splinters, or coarse fibers. For years, my go-to choice has been 1⁄4" hardboard — especially service-tempered hardboard. It’s the standard on a lot of jigs I make and even for drawer bottoms and case backs.
There is one drawback: 1⁄4" hardboard (or MDF) doesn’t provide a lot of surface area for the bearing on a flush-trim bit. You can see this in the box on the next page. On some bits, there’s a sizable gap between the bearing and the cutting edges. Which means you either end up with a web of waste material or the bearing is riding a razor’s edge.
There are two solutions. The first is to laminate pieces of hard-board into thicker blanks. The other solution is to use 1⁄2" MDF. When I started woodworking, this size wasn’t readily available. Now, however, I see it at all the home centers in central Iowa. Thank you, DIY reality television shows.
Templates can be used for more than just curved parts. The straight edge of angles can be shaped with a template. They also come in handy for cleaning up the edges of slots and handholds.
DURABILITY.
Since hardboard and MDF are on the softer side, you may wonder about their long-term durability. I’ve found that while a bearing may burnish the edge of a template, I can use it over and over again without it affecting the results.
There’s an easy way to toughen the surface of a template once you’re satisfied with its shape. Apply a coat of thin or medium consistency CA glue. The glue quickly absorbs into the fibers and hardens the surface.
TEMPLATES IN USE
You have the bit(s) nailed down and the template in hand. Putting them to work is next. The photos on these pages show the wide variety of applications.
TRACING.
The first thing to do with your template is to trace the profile onto the workpieces. This serves as a guide for removing the waste.
CUTTING.
The goal is to remove as much of the waste as possible. I aim for 1⁄16" of waste at most. This puts less stress on the bit, limits tearout, and allows the bit to create a smooth surface. The band saw is my tool of choice for this step. Though a jig saw or a series of hand saw cuts can work too. It depends on your preference and the tools at hand.
ROUTING.
With the work you’ve done, the routing is anticlimactic. A quick zip past the bit. Your main focus is to keep the bearing engaged with the template and rout with the grain as much as possible. This is the essence of woodworking skill: small steps that build confidence.
DOUBLE-UP YOUR TEMPLATES
Thick Template. A thick template allows you to raise the bit so the cutting edge trims the entire edge of the workpiece.
Two-sided templates like the one shown here, capture a workpiece for greater control. You can flip the assembly over to rout with the grain for smooth results.
