Plywood tear out: the fingernails on the chalkboard of carpentry. There is nothing more frustrating than trying to build a clean project, but then having your lines frayed and broken. There are many things that can go wrong, but only a few things that can go right. In this article, we will give you the knowledge you need to make things go right and prevent plywood tear out from ruining your work.
Plywood tear out can be stopped with a combination of proper tools, techniques, and the right amount of patience. You want to check to be sure your saw blade is sharp. There are plenty of helpful hints out there, like scoring or taping off the plywood before making the final cut, that can help prevent plywood tear out.
If you’re tired of putting all of our energy toward a build, only to have it ruined by plywood tear out, stick around. Keep reading to find out how to fix and prevent plywood tear out in just six easy steps.
Tips to Prevent Plywood Tear Out
Every craftsman comes to the dreaded bridge of plywood tear out. You can either cross this bridge with dignity or fall into the river of sloppy work. Preventing plywood tear out all comes down to three things.
Preparation. Technique. Execution.
With a little bit of knowledge and the proper tools, you don’t ever need to witness those torn out plywood edges again. Here are a few ideas to try and prevent plywood tear out.
- Consider buying wood already to size
- Be sure to have a sharp saw blade
- Be sure to have the proper tooth count on the blade
- Use tape on the cutting edge
- Use a scoring cut before making the final cut
These five ideas will help you begin your journey down a clean-cut road.
We will also discuss how to prevent plywood tear out with different tools. Here are several we will cover (the principles we cover will work with ANY saw).
- CNC Router
- Hand Saw
- Table Saw
- Miter Saw
Each of these tools will affect your plywood differently. It’s important to select the right tool for the job.
Here are the six steps to fix and prevent plywood tear out.
Know What Causes Plywood Tear Out
The best way to combat plywood tear out is to know why it happens in the first place. Plywood tear out is most likely to happen for one of the following reasons:
- Cheap or overly thin plywood
- Wrong Saw Blade
- Going Too Fast
- Not Preparing
Avoid these things. Take the next steps to prevent further tear out.
Buy Good Plywood
That’s right; not all plywood is created to the same standards. When purchasing your sheet of plywood, be sure you look it over first. Check to see if the board is warped or if it appears to have some water damage. You will have to look closely, as this won’t be readily apparent at your lumber yard.
Another thing to keep in mind. Be careful using an old piece of plywood that has been sitting in your garage or basement. If there’s any chance that water, or even damp air, came into contact with the plywood, then it’s much more likely to have separation of the layers. And more likely to tear out when cutting.
If you are building something that requires a supreme finish, like a bookshelf or a desk, you want to consider buying brand new plywood with a tight seal.
However, even new plywood will tear out. See more of our techniques below for avoiding this dreaded thing.
Use Proper Saw and Blade Type
The proper blade type is an overall principle. We will go into specific types of saws later in the article. For now, here are a few things to keep in mind when choosing a saw for plywood.
Be sure the blade is sharp. This would seem to go without saying, but you’d be surprised how many of us just leave a blade on a saw until it’s rusting to dust. Before cutting your piece of plywood, take an honest look at your blade. If it’s old and needs sharpening, sharpen it. If it needs to be replaced, well, it may be time.
The next thing to do is to make sure your blade (especially a table saw) has an appropriate amount of teeth. Most tables saw blades come with a standard blade that has a lower tooth count. This lower tooth count will work fine on most things, but with plywood, it will likely cause some tear out.
Consider replacing with a new blade that has a higher tooth count. This will allow for a finer, tighter cut. And usually less tear out. I recommend a blade with 80 teeth for a 10” table saw.
When you cut too fast with a saw, you don’t allow the saw to do the work it is capable of doing. Not only is it dangerous, but you will wear out faster, your blade will wear out faster, and you’re going to have more tear out.
The high tooth count will leave less room between the teeth. The resulting smaller gullet between the blade teeth can not clear out as much sawdust and so the plywood must be feed slower across the blade.
Take your time and find which speed is best for the saw and the wood. We would always recommend that you perform a few practice cuts on a safe piece of scrap before beginning the cuts on your final project.
When you rush, you get mush. And, you’ll end up spending more time correcting your mistakes than actually building your project. Take time before your project and go over everything you’ll need. Review this checklist in your head.
- Do I have the right plywood – new or old?
- Are my saws sharp and have good tooth ratios?
- Do I have the time to do this, right?
Repair if Needed
So, you tried your best to prevent the tear out, but it happened. And it will happen. There are several things you can do:
- Start Over
- Sand it Down
- Frame your piece of plywood
- Try to use some wood filler
You certainly don’t want to waste, so perhaps you can use that board for something else in the future. But, some tear out is really bad. You may just need to get a new piece of plywood and be more careful. This is especially true if you are using thin plywood, where there is no margin for error.
Sand it Down
If you are working with thicker plywood, then you may be able to get away with just sanding down the edge slightly to remove to rough areas. This isn’t ideal, but you can probably get away with it if you are not building something that is going to be viewed on a regular basis.
Essentially place a clean border around the edge the tore out. This could be useful for something that is more likely to be the view, like a desk or a coffee table.
This is a glue-like substance that is used for small wood repairs. Look at your local hardware store for different types of wood glue and filler. While this certainly isn’t a glamorous option, if you need to clean up that edge, some wood filler might get you there.
The best fix is prevention. Tear out is not easy to fix. Once it’s there, it’s there. Even with these repair ideas, your plywood will not look great.
Now that we’ve covered the six steps or principles let’s dive into some more ideas.
Techniques to Prevent Plywood Tear Out
Here are a few of the techniques you can try to stop plywood tear out. This are general principles that will work with almost every type of saw.
- Scoring the wood
- Taping the Wood
- Begin Cut from The End
This simple technique involves making a shallow initial pre-cut. That means marking the line you will be cutting, and then cutting over it with a razor blade or just performing a shallow cut with your table saw.
This technique can be used for all types of plywood with all types of saws. However, you may find that scoring a piece of wood with a razor blade is not that effective in preventing tear-out. It will depend on the plywood’s thickness.
For a table saw, lower the depth of your blade so that it only cuts into about two layers of the plywood. Then cut over the piece of wood to score your edge. After you’ve scored the edge, you can now perform the final cut. You will see a drastic reduction in tear out.
Taping the Edge
Remember that blue papery tape your mom used to tape off the windows before painting the kitchen for the thousandth time? The blue tape you tried to use to repair something but found it worthless? Yes, that tape. It’s called masking tape, and it can be used to prevent plywood tear out.
How do you do it? Just run a strip of blue masking tape through the center of plywood where you plan to cut. Then, slowly cut over it. You’ll find this help in reducing those frayed edges. It works by providing some stabilization against the saw vibrations. This little step could give you that factory edge you want.
Beware! You only want to use the papery masking tape over the cutting edge. If you use duct tape or packing tape, you could clog up your saw. You will also have nasty grime on your edge. Only use masking tape that tears like paper.
Start Cut From the End
You’re making a long cut. It’s going well. The edge is straight and true. You’re almost to the end! Your plywood splinters. Darn.
Instead of starting at one end and finishing at the other, you start at both ends and meet in the middle. Because, with plywood and all other types of wood, when you are finishing the cut is when you’re likely to get the worst tear out.
A caveat. This technique is more suited for routers and table saws. It would be difficult to keep the cut straight with a free hand saw like a circular saw. In this case, you could consider making the full cut, but leaving about 3 inches uncut at the end. Then, come in from the other end.
If you find yourself having to make a long cut, make sure that the starting end of the cut is well supported after it has been cut. Leaving the off cut dangling will cause the uncut end to break off before the cut is finished.
We’ve covered principles so far. Read on to find out how to prevent tear-out with your specific tool.
How to Prevent Plywood Tear Out with CNC Router
If you find yourself cutting with a CNC router, then you know it’s imperative to prevent tear out. This tool is for clean, intricate designs. You don’t want to mess that up. Here are a few ideas to keep those passes clean.
- Be sure you aren’t going too fast.
- Use shallow passes first
- Use proper bit
I’m sure you see a pattern down. The principles apply everywhere. Especially when your CNC is making those intricate cuts, you want it to be moving at a smooth pace. Different speeds will work differently with different woods. But, for plywood, you’re going to want to keep your RPM’s on the lower end.
Shallow Passes First
Set your CNC to make a shallow pass first. This parallels the scoring we talked about previously. When you breakthrough that initial layer of plywood, you’ll find there will be much less fraying in the deeper cuts.
Using a spiral bit rather than a straight bit will make all the difference in the world. Spiral bits come in 3 styles and each has it place when cutting plywood.
- Up Cut bit
- Up-cut router bits are characterized by spiraling blades that will clear out the chips from the work area by pulling them toward the motor of the router. These will produce an excellent cut on the surface away from the motor but may tend to fray the top surface fibers. (See my Article: What is an Up-cut Router Bit?)
- Down-Cut bit
- A down-cut bit will leave a very clean edge on the top surface (the surface closest to the router) but may clog during a plunge cut. (See my Article: What is an Down-cut Router Bit?)
- Compression bit
- A compression bit is a combination of an up shear and a down shear bit. The very end of the bit (furthest away from the router) will have up cutting flutes. The remainder of the bit will have down cutting shear flutes. This geometry will leave clean edges on both the top and bottom of the plywood. (See my Article: What is an Compression Router Bit?)
Different pieces of plywood will have different grain structures. Try to find a piece that has tight grains. You don’t want any loose areas, as this is a guaranteed tear out zone. It’s always smart to perform a few practice cuts to get a feel for what the bit will do to the wood.
Preventing Plywood Tear out When Using a Hand Saw
Now let’s discuss the hand saw. The hand saw is a tricky one. Most of the time, you are going to be more worried about keeping the cut straight. The best way to prevent plywood tear out with a hand saw is to select the appropriate saw and use a low angle technique.
You want a handsaw that has fine teeth and a slim profile. Consider using a handsaw called a Backsaw. This type of handsaw has a rigid spine that helps to keep the cut true. These saws also typically have more teeth per inch, which gives a cleaner cut.
Low Cutting Angle
This is the second tip for cutting with a handsaw. Instead of having the saw blade perpendicular to your board, you want to bring down the angle of the saw so that it is almost parallel to the plywood.
Another way of saying this: Instead of cutting with your blade at a 90-degree angle to the board, try to cut with your blade at a 30-degree angle. This is a very effective way to prevent tear out with a hand saw. You are pushing across the wood causes splintering. Pulling with the wood at a lesser angle allows you to keep your edge clean.
Preventing Plywood Tear Out When Using a Table Saw
Table saws are some of the most effective tools in a workshop. They are also dangerous. Here we’re going to give a guide on how to safely prevent plywood tear.
- Use an appropriate blade with higher tooth count
- Pre-cut your line before making the full cut
- Use masking tape
Some people find they don’t have any issues using their standard table saw blade. If you are going to stick with the standard blade, be sure that it is sharp. If you are making a piece of furniture or wall art, and need perfect cuts, consider upgrading to a blade with a high tooth count, like this one here.
First, change your blade height so that it only takes off the first layer or two of plywood. Then, run your plywood through the saw. This is a “score” cut. Essentially, you are removing the weak edges so that they don’t splinter and fray when you make the full cut.
After the score, you can carefully run the board through for the final cut. Remember the principles we discussed, and go slow. Let the saw eat away at that plywood in its own time.
We covered this in previous sections. Just take a piece of blue masking tape and place it over your cutting line. The tape will hold those edges tighter to keep them from fraying.
Combine all three of these techniques for the best results.
How To Prevent Plywood Tear Out With Miter Saw
You’ve got your miter saw out, and you need to make that perfect cut. Here’s how you do it.
- Be sure the throat-plate is flush with the table of the saw
- Use a sharp blade
- Use a piece of scrap underneath the board you plan to cut
When it comes to preventing plywood tear out, it’s all about supporting that bottom layer. Here is some more depth below.
Flush Throat Plate
Your throat plate is the portion of the saw right under the blade. It is often made of tough plastic. Sometimes your throat plate won’t be level. If this is the case, you’re going to have space under the board. Space means no support. No support means to tear out!
Re-level your throat plate before making any cuts. You may need to replace it.
The same principles apply to all saws. You want a sharp blade with a fairly high tooth count. Be sure to double-check that your blade is ready for the job. If you need to make particularly fine cuts, you may want to replace the stock blade for a blade with a higher tooth count.
If you want a quick hack, this is it. Take a piece of scrap and secure it below your plywood board. When your miter saw cuts through, your plywood will have support.
Be careful with this. You want to use a large enough board underneath your plywood. Small scraps could become dislodged and cause an uneven cutting surface. Or a projectile. Be sure to wear those safety glasses.
You can also use tape and scoring with the miter saw. Use these techniques the same way you would with any of the previous saws mentioned.
Plywood tear out is a big problem. But you will see a massive decrease in tear out when you apply the principles and techniques listed in this article. Remember to be safe. Don’t try anything you’re uncomfortable with. If you’re unsure about something – STOP – it’s not worth an injury.
There is nothing like a job well done. Take your time; go at a steady pace. Haste really does make waste, especially when it comes to plywood tear out.