Working with plywood has become a common occurrence for most do–it–yourself enthusiasts like myself. I decided to build a wardrobe in my room the other day to create more space but had to spend a lot of time fixing places where the plywood tore out. How do you prevent this? Here is my informative, quick guide to help you to prevent tearout in plywood.
Tearout in plywood happens often and can be caused by a range of different factors like using the wrong blade or even the wrong type of machine. Expert woodworkers recommend using the correct blade, the suitable wood saw, and scoring the plywood as the best way to prevent tear-out.
After much research and talking to some expert wood craftsmen, I managed to get the hang of working with plywood. I used to dread the idea of working with this material because of it tearing or chipping so quickly. Still, it has now become one of my favorite materials to work with. This post will look at an easy and quick guide to prevent tear-out in plywood.
What Causes Tearout in Plywood
Plywood consists of multiple layers of veneers that are put together by an adhesive. This means that when a saw goes over the grain of the plywood, the fiber of the veneer comes loose, and it leads to tear-out.
It is not surprising that a sawblade will cause tear-out if you take into account that some saws run at between 2900 and 3990 revolutions per minute. The plywood fibers break down and come apart when exposed to that amount of velocity.
Preventing Tearout In Plywood
Tearout in plywood is something that we want to prevent at all costs. The time and energy it takes to fix the tear-out is a damper on any project. So here are a few pointers on how to prevent tear-out when working with plywood.
Choosing The Most Suitable Machine For Cutting Plywood
The quality of a cut can be severely affected by the choice of cutting machine. Using the wrong machine for your application will make your task more challenging and increase the chance of tear-out. Here is a list of different machines to use for the cutting of plywood:
- Table saw – a Table saw equipped with a suitable blade will be a good option for large sheets of plywood. By using the correct blade, it assists in the fight against tear-out. A table saw offers excellent support to sheets of plywood, but this machine is not easy to move around. So if you are looking for mobility, then use a circular saw.
- Circular saw – a Circular saw equipped with a suitable blade will be a good option for smaller sheets of plywood. A circular saw is a much more mobile piece of equipment than a table saw, but it doesn’t have adjusters, so make sure to make the correct measurements. Cutting angles in plywood with a circular saw increases tear out, so instead, leave this job for a miter saw.
- Miter saw – a Miter saw equipped with a suitable blade will be a good option for cutting plywood to angles. Making angled cuts to plywood increases the chance of tear-out in plywood. So for precision work, a jigsaw might be a better option.
- Jigsaw – A Jigsaw equipped with a suitable blade will be a good option for precision work on plywood. Cutting plywood with precision is what a jigsaw does best. It sure beats cutting plywood by hand.
Using The Correct Woodworking Blade For Plywood
Most people think that all woodcutting blades are the same, but they are not. Using the wrong blade will make tearout in plywood worse. When using a blade in any wood cutting machine, expert advice is to use a blade that has between 60 and 80 teeth. Different machines use different blades, so here is a list of suitable blades:
- An 80 tooth combination sheet blade is an excellent option to be used in a table saw as the beveled-shaped teeth will eat through the veneer of the plywood. Don’t feed the plywood through too fast, though, as this may cause tear-out.
- The Freud 7-1/4″ x 60T blade is a good option for using on plywood in a circular saw. A circular saw comes standard with a 24 tooth blade, but of course, with plywood, we want to use a blade that makes better contact to prevent tear-out.
- The Freud 10 inch 80 tooth ultimate plywood and melamine blade is an excellent option in a miter saw. These blades are designed to prevent tearout in plywood.
- The Bosch 4 ½ inch 12 TPI jigsaw blade is a great option to use with a jigsaw. It cuts plywood like a trooper, and because of the up and down movement of the jigsaw, it does not cause so much tear-out in plywood.
Always make sure to keep saw blades clean and sharp as this will aid in the prevention of tear-out in plywood.
Use Of Raised Blade And No Clearance Plates Reduces Tearout
When cutting plywood, raising the blade height can make a big difference in cut quality, and it helps reduce tear-out to the plies. Most of the time, safety standards will suggest setting the blade low; however, this cuts away at the underlying plies of the veneer first, leaving the top of the face poorly supported as the teeth slice through.
For a cleaner cut, raise the blade a couple of inches. The teeth will make contact with the sheet while moving nearly straight down, so the face veneer is supported by the plies that lie underneath. Before cutting plywood, swap out your saw insert plate for a no clearance insert plate to reduce tear-out on the underside of the sheet.
The blade will cut the opening in this type of insert to match the thickness, in turn offering support to the workpiece edges along the cut. No clearance inserts are available for most saws.
Scoring Plywood to Prevent Tearout
Scoring simply means cutting into the outer veneer of the plies first before attempting to cut entirely through the plywood. The method of scoring the plywood has proven to be very effective in preventing tear-out.
To make the first scoring cut across the bottom of the plywood, set your blade about 1/16″ above the table of the saw, make a complete pass-through. There’s not a considerable amount of downward pressure applied from the blade, so it doesn’t impact the ply fiber as much and leaves a nice, clean-cut surface.
The next thing to do is raise the blade to the accurate height to cut the plywood to size. By creating this scoring cut, you’re reducing the impact to the ply fiber, keeping them where they should be. Some table saws come with a standard scoring option, but if your saw does not have this capability, follow the guide as highlighted above.
Some woodwork enthusiasts use a straight edge and a sharp utility knife to do scoring. I suppose this method is especially effective when you do not have access to a saw or even a power failure. Scoring plywood is a valuable option in terms of preventing tear-out.
Using Tape To Prevent Tearout In Plywood
Taping over the main cut line with blue, green, or white masking tape can help hold the plywood fibers in place, reducing tearout in the plywood.
When applying the masking tape, be sure to use it on the cut side where tear-out is most likely to happen. When unsure, play it on the safe side and simply tape both sides; then look at the end result. Be sure to always press the masking tape down firmly so that it adheres well to all the plywood surfaces.
When taking off tape applied to prevent tear-out on the edges of the plywood, be sure to pull the masking tape off in a way so that the tape breaks contact with the contact surface of the plywood, away from the edge of the cut.
If the masking tape is pulled off in reverse, it could potentially help lift plywood up, thus causing the tear-out that we are trying to prevent in the first place.
Using Pre-cut Plywood Sheets To Prevent Tearout
What could be better than looking at different options to prevent tearout in plywood? Well, here is one to prevent tearout altogether by purchasing pre-cut plywood sheets.
This specific option may be more expensive, but it might just be the solution to look at in some cases. If you don’t have the correct machinery, blades, or know-how, then this is the option you need to look at. Hand the measurements of the sizes you need over to the professionals and let them deal with the problem of tear-out.
Plywood Splitting Versus Plywood Tearout
We are now quite familiar with the term tear-out, but one of the other problems that I encountered with the wardrobe that I built was the splitting of the plywood that in turn led to the tear-out of big chunks of plywood.
Plywood splitting occurs when the fasteners that you use to secure corners of plywood to each other causes the plywood to buldge and then tear-out at the site of the fastener. The secret to preventing this type of tear-out from plywood is to drill a guide hole into the plywood first.
Using cold glue between the seams before tightening the fastener is an excellent way to keep the plywood on track. There is a wide variety of fasteners suitable for use with plywood. It’s an excellent idea to play around with different options until you find something that prevents plywood splitting and, in essence, prevents tear-out.
Fixing Tearout In Plywood
Tearout of plywood due to splitting is relatively easy to fix because of the big chunks of plywood that “tore out.”
Here is what you do:
- Start by putting wood glue into the edges of the tear-out.
- Secure the chunks of plywood that tore out.
- Remember to drill a hole for the fastener this time; otherwise, the same thing will happen again.
Tearout as a result of cutting is a little more tricky to deal with. If the entire cutting edge is affected, we might need to mix a wood filler using sawdust and wood glue to repair the edges or deep gouges. The match in wood color makes it difficult as some stains do not take on certain glues.
I have found that it helps if I use bigger pieces of plywood to build up the edges. This method requires some extra sanding, but its end result is worth the extra work.
A Quick Guide To Prevent Tearout In Plywood
Tearout in plywood proves to be a common problem in all woodworking shops. Although tear-out in plywood is challenging to fix, it is possible to prevent tear-out. This is how to avoid and prevent tearout altogether.
Step 1: Use Suitable Machines And Blades
The use of suitable machines and blades is the best and first option to prevent plywood tear-out. Remember to maintain machines and keep blades clean and sharp.
Step 2: Use No Clearance Inserts
The use of no clearance inserts aids in the goal of preventing tear-out. Remember to swap around the inserts for the different applications.
Step 3: Use Masking Tape
Masking tape is an easy resource to use but be careful when pulling it off as it could also lift the plywood.
Step 4: Use Pre-Cut Plywood Sheets
If all else fails, then purchase sheets already cut by the professionals. Sometimes we do save money this way.
Conclusion
Plywood is a wonderful and cost-effective material to work with. When working with plywood, it could lead to the tear-out of the plies. It will, in turn, lead to frustration and time delays. So to prevent tear-out, follow the recommendations from woodworking experts and guides like this. If you do that, you will no longer have to deal with tear-out issues.