Preventing Tear-Out in Plywood #diy #woodworking #wood

Plywood, moreso than other woodworking materials, tends to "tear out" when you cut it across the surface grain. The saw blade lifts the veneer as it exits the wood, breaking it and leaving a row of splinters. The cut looks ragged. There are are several things you can do to prevent this tear-out, and Nick shows one of the easiest: Tape the cut. Apply a length of masking tape over the line you wish to cut. This keep the grain from breaking and greatly reduce the splintering. And you can further reduce the tear-out by applying a great deal of momentary pressure to the tape with a roller or a burnisher, mashing the adhesive deep into the grain.

Song: ES_Good Company (Instrumental Version)
Artist: Nyck Caution

[WorkshopCompanion]

Moreso than any other woodworking material, plywood wants to “tear out” when you cut it across the surface grain. The saw blade seems to lift the veneer as it cuts, breaking the grain and leaving an unsightly row of splinters. The cut looks ragged. Oftentimes, you can greatly reduce this tear-out by raising the blade an inch (25 mm) or so above the plywood surface – this changes the angle at which the teeth cut. You can also switch to a sharper blade, or one with more teeth. Blades made specifically to cut plywood often have 80 or more teeth. Each tooth takes a smaller bite and leaves smaller splinters.

You can also switch a a blade with a different grind. There are five common grind available -- ATB (alternate top bevel), HATB (high or steep alternate top bevel, ATBF (alternate top bevel and flat, your standard "combination blade), FTG (flat top grind, standard for ripping) and TCG (triple chip grind). We tested all of these, and found a marked difference in the the amount of splinters they produced when cutting plywood, and where they left them. Some produced splinters on top of the board, some on the bottom, some and top and bottom, and some neither top nor bottom. We found the grind that produced the least splinters was HATB.

But you don't always have time to switch blades, or you don't have the right blade to switch to. So what can be done to reduce splinters with an ordinary ATB or ATBF blade? Some craftsman suggest putting a sacrificial board atop the work and cutting through both. This works, not just because the sacrificial board keeps the good wood from splintering, but you also have to raise the blade and change the angle at which the teeth cut. I rarely do this because (1) I don't usually have a lot of wood to sacrifice, (2) it's often difficult to secure the sacrificial board to the work, and (3) I like to see what I'm cutting.

The best solution I've found is to score the cut before you do the cutting. In fact, there are (very expensive) saws made especially for cutting plywood that have scoring blades ahead of the cutting blade. If you don’t have one of these, you will have to score the plywood by hand with a knife. Be sure to score it on both sides of the cut if you want to use both pieces after you cut them.

Saw blades with an alternate top bevel (ATB) grind allow you to score with the blade itself. Set the saw to make a very shallow cut -- only 1/64" to 1/32" (.4 to .7 mm) deep -- and make a pass. The beveled teeth with act like scoring knives and score the veneer. Then raise the blade and make your cut. You can also do this with some dado sets, as long as the outside trim blades are ground with alternate bevels AND the chippers cut just a little less deep than the points of the trimmers. But it may not work as well with blades that have triple-chip (TCG) and combination (ATBF) grinds because of the flat-ground teeth.

However, whether you score with a knife or the tips of your blades, the technique requires time and precision. So craftsmen have come up with a simpler solution: Cover the cut line with a piece of masking tape. The tape holds the veneer together and prevents the grain from splintering as it’s being cut. But in order for this to work well, you have to (1) make sure the board is clean and free of sawdust, and (2) apply a great deal of pressure to the tape – just for a moment – to force the adhesive down into the grain. I usually employ a veneer roller to do this, but you can also use a burnisher, rolling pin, the rounded edge of a veneer hammer, anything with which you can apply pressure. I’ve even used the rounded end of a screwdriver handle from time to time when there wasn’t anything else handy.

By the way, this technique can also prevent tear-out in brittle woods like cherry and oak, helping you to make cleaner cuts. I once built a clock case from thermally-modified oak which seemed to splinter and chip if you just looked at it the wrong way. But the pressed-on tape seemed to help. The cuts still weren’t perfectly clean, but the tear-out was reduced to a point that the splinters were barely visible.

And if removing the tape seems to lift the veneer and pull away a few splinters, try wiping the tape with mineral spirits or naptha -- this dissolves the adhesive.

[Paloriel]

These videos are always incredibly concise and informative, had no idea that applying pressure to the masking tape had such a big impact

[eliguy]

I have done about 5 minutes of woodworking my entire life and yet watching someone explain how to prevent plywood tearing is super interesting.

[Silver-Rose]

He showed off the problem, a very good solution, an widely popular alternative that is less time-consuming, and a quick tip to make said alternative even better, while also showing all four results

[misternoodle]

I am not into woodworking and am not your general audience. With that being said, this short video absolutely blew me away in terms of quality and engagement.

I was fascinated the whole way through without being given too much information. I found myself mentally asking questions that were answered for me. I was given a concise comparison at the end. Last, there was no "selling out" and telling me to buy some course. It was just a well-done video by someone who obviously knows what they are talking about and understands how to share their passion with ANYONE.

This is likely a master in their field and I got that in a short. Very impressed.

[Tenkurel]

I started the video and thought aloud, "You can use tape too!", and then when he mentioned the tape, I felt like I just got an A+ from my woodworking teacher.

[guroranko]

I was a city kid and we lived in an appartment, so I never really had access to woodwork. Now I'm an adult in a house and there is always some sort of maintenance that needs doing. In the old days everyone knew how to fix everything, now it's quite rare, so I am so grateful for people who take their time and spread the knowledge on how to actually make material things necessary for day to day living. ❤
It doesn't matter if it's gardening, making a bookcase, fixing a hole in a pocket, fixing an electrical device or tuning a piano, crafts are simply super important and we should cherish them.🌷

[shaiz]

What about using a sacrificial wood plank placed on top of the one you're cutting?

[aarongreer]

This man is one of the greatest content creators on the platform.

[ssccaappeeggooaatt]

Not even a woodworker in any capacity. I just love watching

[sstankfish]

This guy is truly the absolute greatest teacher. So clear and straight to the point.

[EastWindCommunity]

Here I am, a barbarian, running a 120 grit pad down it a couple times and calling it good. That scored cut was incredible to watch!

[ole]

The kind of knowledge you pick up from years of experience

[albinocyclopse]

I've never done any woodworking in my life, but I love watching this guy. So concise, pleasant and informative.

[c.p.]

Geez how have I lived without this channel. It would have saved me so much angst if only I found it sooner

[garnaudiz]

Thank you, I will remember this forever.

[Mervyn_]

You can also score the wood by starting with a real shallow cut, only cutting the veneer. On your second cut you can cut all the way through. This will be a very clean cut as well.

[OmnipotentNoodle]

This channel is so excellent. You are an excellent teacher, and you've already constructed an incredible, free repository of carpentry knowledge. These videos should be preserved!

[ItchyCinderBlock]

You are such a wealth of knowledge sir!

[lillyanneserrelio]

Outstanding channel. No frills. No filler. Just practical knowledge. This is the kind of USEFUL info you WON'T find in a book.