Woodwork is often a delicate art involving a lot of different techniques and tools. Because of this, there are naturally some things that could go awry with woodwork. One of these things is racking.
What is racking? How can you prevent it? Racking is when a piece of woodwork leans to one side, causing vibrating, sliding or shaking of the woodwork piece. Racking can happen from uneven pressure and incorrect clamp or vice use.
Racking can be prevented by learning how to correctly use clamps and vises and distribute pressure when working with wood, and can also be prevented by using different features in the vises and adding support to the woodwork itself.
Describing racking in woodwork can get a little technical, but have no fear; we’ll explain everything you need to know about racking in woodwork, the different types of vises that may contribute to racking, and how to prevent racking.
What You Should Know About Racking in Woodwork
Racking in woodwork can be a simple or a complex problem in woodwork, but either way, it’s a common one. Let’s take a look at what racking is, the two types of racking, problems racking causes, and what types of woodwork can fall victim to racking.
What is Racking?
At its simplest, racking in woodwork can be defined as a piece of woodwork leaning to one side. When woodworking pieces are subject to racking, they may vibrate, slide or shake when someone tries to use it – all in addition to the piece leaning to one side.
A user from Woodwork Forums wrote a great visualization of racking: “Imagine you’ve made a stick figure cube, just 12 sticks nailed together to make a cube. Push on it anywhere and it will go out of square, that’s racking.”
Racking can be a little more complex than a woodwork piece just leaning to one side, though. Racking also has to do with vises used in woodwork. When the pressure from the vice jaws on a woodwork piece isn’t equal because the stationary jaw isn’t in line with the sliding jaw, racking happens.
Additionally, racking can happen when an object is clamped with vice at one end, but there is nothing to balance the load at the other end.
There are actually two types of racking that can happen in woodwork: top to bottom racking and side to side racking.
Side to Side Racking
Side to side racking happens when a woodwork piece is clamped with a vice at one end, but has nothing to balance the load on the other end, as previously mentioned. Side to side racking can happen with all types of woodworking vises, but it’s more common that it happens with face workbench vises.
Face workbench vises have jaws that are much wider than other types of vises, which can lead to more of the woodwork being clamped with the vice and less of the woodwork being balanced on the other end.
Top to Bottom Racking
Top to bottom racking can happen when a woodwork piece is clamped at the top of the jaws of a vice. The top edge of the jaw can tilt away from the woodwork piece that’s clamped, leading to uneven pressure.
Top to bottom racking most commonly happens with vices that are a plain screw and quick release.
Types of Vises That May Contribute to Racking
To put racking into more perspective and to understand the role of vises in woodwork racking, it’s helpful to know about some of the different types of vises and what they’re used for.
Face vises are specifically designed for holding wood pieces when sawing or drilling is going to be performed. They are made of a movable front jaw which is mounted to a broad beam which slides in and out of a matching channel. The entire vise is attached to the benchtop from below and screwed in a clockwise motion to bring the jaws together.
Today, modern face vises are also referred to as woodworker’s vises. They come in almost any size for a variety of different needs and uses.
Workbench vises, sometimes referred to as end vises, are installed on the end of a bench. They are used to clamp workpieces to a bench by clamping the woodwork piece between their jaws.
Workbench vises are different from some other vises because they become a part of the bench itself, rather than staying a separate object.
Plain Screw/Quick Release Vises
Plain screw vises are a standard and more simple type of vise used in woodworking. They are made up of a traditional screw system, in which turning the screw through the rotation of the handle moves the jaws of the vice.
Plain screw vises are used by amateur and professional woodworkers alike, and are relatively easy to use. The downside is that they may be more time consuming to use than other vises.
Quick Release vises are very similar to plain screw vises. The main difference is they have a quick release mechanism that allows the jaws to be quickly opened and adjusted without having to manually rotate the handle.
Types of Woodwork That Racking Can Happen To
Racking can happen in a lot of different types of woodwork, a lot of them being furniture or home-related. Racking can happen to:
- Other free-standing shelves
- Kitchen islands
Racking can also actually happen to vises in addition to woodwork. If a piece of woodwork is placed incorrectly into the vice jaws, the vice can become twisted and hard to untwist.
How to Prevent and Avoid Racking in Woodwork
Luckily, racking in woodwork can be prevented and avoided so long as a little research is done and a little knowledge is obtained. Let’s walk through the ways to prevent and avoid racking.
Learn How to Use Vises Correctly
You’ve likely noticed that vises are a big factor when it comes to racking in woodwork. Side to side racking and top to bottom racking both happen from the incorrect use of vises! To prevent racking in woodwork from incorrect vise use, the simplest solution is to learn how to correctly use any vises you may be working with.
It’s important to equally balance and distribute the weight of any woodwork pieces that are clamped by vises. It’s also equally important to make sure vises are clamped equally on jaws.
Add Features to the Vises
Features can actually be added to different vises used in woodworking to help prevent any racking of woodwork that may be used with them.
Toe-In Features: Prevent Top to Bottom Racking
One of these features is a toe-in feature, which helps prevent top to bottom racking.
Toe-in features are regular jaws that are tilted slightly inwards. This helps because it assures that when the jaws of the vice are empty and closed, they only meet at the top, resembling a narrow upside-down V shape.
Toe-in features also help avoid racking because the sliding jaw is unable to slide outward when an object is clamped. This way, the stationary jaw remains parallel with the sliding jaw, so all the pressure is equal. Voila!
Offset Screws and Wooden Spacers: Prevent Side to Side Racking
A few other features can help prevent side to side racking, and they’re relatively simple. One of these features is to offset the screw of the vice, so it’s closer to the right guide bar than the left guide bar.
When clamping down on a woodwork piece on one side of the jaws, offsetting the screw avoids racking to one side or the other.
Additionally, a wooden spacer in the same thickness as the clamped woodwork piece can be placed on the other side of the vice jaws. This keeps both sides of the jaws evenly spaced, preventing any racking.
Add Support to the Woodwork Itself
A little extra support can be added to any woodwork pieces that may be prone to racking. There are a lot of different ways to do this!
For example, “L” brackets can be used on the back corners of open back shelves or bookcases to prevent and avoid racking. Additional wood support can be added to the frame of any woodwork that is leaning or racking to straighten it out; it can also be added as a precaution to make sure racking doesn’t happen. For example, diagonal braces can be added to the inside of a table, forming an “X” shape or a partial “V” shape under the table, and offering more support.