How to reduce or completely eliminate chatter and skipping when planing – the brief summary
There are three things that cause chatter and skipping when planing with bench planes: Too high cutting resistance, excessive play among the parts of the plane, and a poorly fastened workpiece.
Lower the overall cutting resistance:
- take a lighter cut
- sharpen the blade
- camber the blade/iron
- wax the sole
- skewing is a good way to reduce the resistance
- plane with the grain
Reduce or completely eliminate the excessive play among the plane components:
- check that the frog and the blade are bedded properly
- check the blade tension
- check the sole flatness
- check that the workpiece is held tight without play
- upgrade to the thicker blade and cap iron/chip breaker
In this guide I will dig deep into one common problem with hand planes, some call it skipping and others refer to it as a “chatter”. As a matter of fact, these two terms don’t actually refer to the same exact phenomena. Let’s dig deeper and explore what they are and what causes the problems.
The bench plane has been designed for three jobs: to straighten, to smooth, and to remove wood. In an ideal world, all hand planes perform the aforementioned tasks without problems. But more often than not a woodworker finds out that his or her hand plane has some mysterious troubles.
What is hand plane skipping?
Hand plane skipping is a happening where bench plane jumps and skitters, biting irregular series of indentations along the way.
What is the cause of plane skipping?
Skipping happens often with hardwoods with hard to plane qualities. Too deep of a cut and/or not so sharp plane iron causes woodworker to use too much power when planing to overcome the resistance, and the plane starts to stutter and cut erratically. When you use lots of power you tend to lose the finesse of your planing technique and raise the occurrence of small errors in plane handling.
What is hand plane chatter?
Hand plane chatter is a specific situation where the bench plane blade(iron) will skip minutely across the surface planed, creating a very close spaced series of minor parallel indentations. Chatter marks are easily removed with little scraping or sanding.
What is the cause of hand plane chatter?
Basically plane chatter is caused by a flexing of the blade(iron), or the plane body itself. During the cut, the blade is forced deeper into the wood by the resistance induced, until the stress of the flexed iron overcomes that force. Blade then rebounds and the cycle happens again.
What are the remedies for plane skipping and chatter?
Lower the cutting resistance
Lowering the overall combined cutting resistance is the key. Let’s take a look at how you can reduce it.
Take a lighter cut.
The depth of the cut should always be in relation to material planed. Softwood will allow a greater depth of cut than hardwood.
When planing gnarly and hard woods and getting skipping or chatter, thin shavings are the must. With a lighter cut, your plane cuts easily and you have a full control of the process.
Start by retracting the blade fully by turning the wheel adjuster anti-clockwise. With the blade retracted fully, move the plane across a flat board, slowly advancing the blade with turning the wheel adjuster clockwise. Stop when the blade makes contact with the board.
Observe at where the shaving is coming up through the mouth. Usually, the shaving is leaning to the left or right. Swing the lateral adjuster lever to bring the shaving closer to center. If the shaving is coming out on the left side, move the adjuster lever to the left and vice versa. Lateral adjustment is perfect when the shaving is coming out right in the center of the mouth.
Sharpen your blade(iron) – Most expensive plane is useless if used with a blunt blade.
Sharp blade/iron is essential when reducing the chances for hand plane skipping and chatter. Sharp blade cuts easily with low resistance.
The properly sharpened blade will easily cut the hair from your forearm or slice a thin shaving of end grain from a piece of pine. If the blade isn’t sharp enough then you need to sharpen it.
Learning to sharpen your tools is the most important skill a hand tool woodworker should poses.
There is a multitude of ways to sharpen blades but all of them should aim to the ultimate goal: A sharp edge is a zero-radius intersection of two planar surfaces. If the edge is honed as close to zero radii as is possible, the edge is as sharp is it can be.
Camber the blade/iron
For the lower cutting resistance, an important aspect is also the properly cambered blade, at least when planing extremely hard woods or thick shavings with a moderately hard wood. Without the cambered blade, the likelihood for skipping and chatter is much bigger and the resistance and the force needed are greater.
So what is the camber and how it helps?
Camber is a slightly convex shape of a tool edge when viewed from the front or back. It makes the cutting impact progressive when the plane contacts with the wood. At first, it is the frontmost part of the curved edge that digs in, then gradually more and more of the cutting edge comes in contact with wood.
Wax reduces the friction
Keep old paraffin candle at hand on the workbench. When planing, make the habit to wipe the sole from front to back with a candle. You’ll notice the difference immediately. Amount needed is just a tiny swipe back and forth and you are good to go for 20-30 passes with a plane. That small amount of paraffin is not going to give problems with finishing. If you are concerned, use the card scraper as the last stage before finishing.
Other things to check when encountering skipping and chatter
Check that your plane Iron is bedded properly
One common cause for blade chatter is if your frog’s top surface isn’t flat. Blade/iron should lie tightly with no gaps on top of the frog. In other words it should be bedded properly.
To check and flatten your frog, remove it from the plane body and unscrew the lever cap screw. You can’t lap the entire top surface because of the lateral adjuster lever, but that’s not a problem. First two to three inches are enough. Lap the frog with sandpaper on top of a flat surface such as a thick glass plate or another flat surface. Check the fit with a blade.
Check that you have the blade under good tension.
Lever cap is holding the blade/iron in place on the frog. If the lever cap doesn’t provide enough pressure to keep the blade tight, the blade chatter could result. Tighten the lever cap screw if needed. You need to find a sweet spot where there is just enough pressure to keep the blade tight but not so much as to prevent the depth adjuster to work. I recommend tightening the screw with a 1/8 turn at a time. When you have found the right tightness you rarely need to readjust it.
Check that the sole of your plane is flat
The sole of a plane should be perfectly flat for it to cut evenly and without problems. To check the sole flatness you need a sharpie, abrasive paper and flat surface such as a thick glass plate or machined cast iron table of jointer or table saw. Mark the sole of the plane with a sharpie and run the plane across the abrasive paper on top of the flat surface. If the ink wears off evenly, you have a flat sole. If high and low areas are present, you need to lap the sole. One important point: The plane must be fully loaded with a blade, chip breaker and lever cap and the movement and pressure must be similar than when planing with wood.
Skew your iron as you plane.
Skewing is a good way to reduce the chatter at the beginning of the stroke. Usually, blade chatter or skipping happens at the first couple of inches when starting the cut. Skew the plane for the first couple of inches then straighten out the plane.
Check that you are planing with the grain.
Plane always with the grain. If you get skipping, check that you are not planing against the grain.
Check your workbench and work holding
Good and sturdy workbench is just as critical as is good and tuned hand plane for best results. If your workpiece wobbles and trembles it is absolutely certain that you get some troubles when planing. Make sure that the workpiece is well clamped to the workbench. If your workbench is flimsy, a good way to make it more sturdy is to fasten it to the wall or better move it to the corner and fasten to both adjoining walls.
Upgrade to the thicker blade/iron and chip breaker
A thicker blade can also reduce chatter from happening. The Vintage Bailey type planes (Stanley and Record) can sometimes benefit from thicker blade and chip breaker upgrade. Makers such as Lee Valley Veritas and Hock tools make good quality upgrades for common bench planes. I would still first try the other means listed above before considering an upgrade.