How To Stop Wood From Splintering When Cutting
Stuck with having to hide the splintered edges of the board you just cut or worse tossing it? Learn how to stop wood from splintering with these tips.
One of the biggest challenges that a beginner faces when cutting wood for the first time is how to keep wood from splintering when cutting it.
This can ruin your project!
Often I end up with a piece I can’t use, ending up wasting wood and my time.
So how do you stop wood from splintering when cutting it? It’s simple, support the wood you are cutting along it’s entire length on both sides of the cut.
There are a few ways to support the wood and it depends on the material and saw you use.
Why Does Wood Splinter When Cutting It
Wood is composed of fibres that runs along its length. Think of it like a bundle of toothpicks.
When you crosscut wood (across the grain, not with it), the saw is trying to cut those fibres in half. However the fibre is flexible and prone to separating if stressed. We’ve all seen the stereotypical exploded tree trunk hit by lightening where shards of wood are sticking up in all directions.
If those fibres are supported, they have no where to go and so they stay put. However if there is nothing behind the fibres, they will pull away from the wood surface and then you get splintering.
Going back to the toothpick example, try cutting the bundle of toothpicks without having toothpicks go everywhere – probably impossible unless you hold the toothpicks together really well or cut them on a hard surface or use a really sharp, fine saw.
Ripping wood along the grain usually doesn’t cause any splintering. Similar to how cutting through the toothpicks lengthwise just parts them.
Stop Wood From Splintering When Cutting With A Table Saw
A table saw blade rotates in a downward motion. So any splintering or tear-out is going to happen on the bottom of your workpiece.
The best option to minimize splintering is to use what is called a zero-clearance insert. Every table saw has a throat plate that sits around the saw blade and it’s main purpose is to support wood, so small pieces of wood don’t go into the hole around the blade.
Standard throat plates that come with your saw have a wide slot that is designed to accommodate a large range of blade thicknesses. The plates are usually made from metal for durability, so the saw manufacturer wants to ensure the blade won’t contact the edges of the slot. So the slots are made wider than necessary to provide enough clearance.
You can replace the throat plate though with a zero clearance insert. There are after-market ones made of various materials such as MDF or plastic. Here’s a list where you can find the right one for your particular saw brand and model: Zero Clearance Table Saw Inserts
Or make your own. Here is a video that demonstrates this:
You can of course make multiple table saw zero-clearance inserts for different blades and even for common dado stack widths.
If you don’t want to go through the effort of creating inserts, you can also use a thin piece of sacrificial plywood underneath the workpiece you are cutting and send both through the table saw at the same time.
Or you can also use a table saw sled. Most sleds are setup so that the sled bottom is one big zero clearance insert. In fact some, like the one I built, use a special replaceable middle where you can have different inserts depending on blade angle or blade thickness if you use dado stacks frequently.
Another alternative you can consider is dropping your saw blade down to having it just lightly graze the surface of your workpiece. This then creates a shallow groove that has less chance of tear-out. You then raise the saw blade to cut through the workpiece fully and run the piece through again. Just takes more time if you have a lot of cuts to do.
How To Avoid Circular Saw Or Jigsaw Tear-out
Unlike a table saw, a handheld circular saw or jigsaw cuts in an upward direction. So tear-out will typically be on top of the workpiece as you can see in the lead photo.
Some woodworkers add a zero clearance plate to the bottom of their saws to stop wood from splintering. That can work but keep in mind that the saw baseplate has to be held tight to the workpiece for this to work.
A better alternative is to score along the cut line with a utility knife. This severs the fibres and when the sawblade cuts, the surface fibres won’t splinter.
You may also have seen some advice to put masking tape over the cut line. That usually doesn’t work that well as you are still not stopping the grain from lifting. Instead it will lift a large section instead of just a few splinters.
What To Do When A Miter Saw Splinters Wood
Mitre saws are great for quick crosscuts in dimensional lumber such as 2x4s. But they do have a tendency to create a bit of tear-out at the back of the cut as well as the bottom.
A zero clearance insert works for the bottom of a cut. There is a special tape that you can buy that is stuck on top of the factory supplied clearance plate and then you plunge your running saw into it.
Alternatively you can place a thin piece of plywood underneath the workpiece and use it as a sacrificial backer board to stop wood from splintering.
For the back of the cut a sacrificial backing piece works too. You could also add a more permanent fence that gets screwed to the existing metal fence.
But keep in mind that any permanent fence will only work for one particular angle of cut. If you do a lot of 45° cuts you may need two fences that you can swap out.
How To Cut Thin Plywood And Other Wood Without A Saw
Who says you need a saw to cut thin wood?
For plywood and other wood that is thinner than 1/4″ (6mm) you can use a simple utility knife to cut the wood to size.
Make sure to use a fresh blade. Cutting plywood will dull the blade quickly, so make sure to replace a blade after several cuts, especially when you notice the knife is no longer cutting well.
Here are the steps to cutting thin wood with a utility knife:
- Use a straightedge such as a rule or level.
- Mark out the line and line up the straightedge along it.
- Make sure the plywood or wood is on a sacrificial surface that won’t harm the knife blade.
- Run the knife blade along the straightedge, making a few light passes at first.
- Keep making passes until the wood separates.
- Sand down the edges as needed.
Cut Wood Trim Without Splintering
For wood trim such as baseboards, shoe molding, crown molding or chair rail molding you can cut them with a mitre saw or table saw. However you have to be careful of splintering.
The tips above will help with wood trim as well.
However a better alternative if you are cutting a lot of molding is to buy a mitre shear. It has a guide that you can adjust for multiple angles, plus a sharp blade that will shear the wood fibres better than a saw blade and stop wood from splintering.
So now you no longer have an excuse to allow wood to splinter when cutting. For your next project you’ll be able to cut all of your parts without wasting time and material having to cut the parts twice or put up with splintered edges.