Cutting with Scroll Saw Blades

The important thing to remember is that you learn from experience. I started with the scroll saw in order to give my children a saw to cut in wood on. I was tired of hearing the words, “can you cut this for me”?

I have tried to teach them, and so I have taught myself. I will be using the Olson blade number that you would buy them in the store and, at times, describing a general blade. The numbers that you see are Olson numbers. They often have letters with a number like an R or F and others.

These letters indicate reverse teeth or a fretwork blade and even skip tooth blades, not to mention spiral blades. Fretwork blades produce smooth cuts that need no sanding.

Reverse tooth blades need no sanding on the bottom because they do not cause burs on the bottom. Experiment with various blades. I have included some TPI numbers, which means teeth per inch.

I have also used the Universal number, which also means little to me. These numbers do not describe the blade good enough to purchase the correct blade. The Olson numbers are a better standard to buy blades. Ignore all numbers and get to know your Olson number.

  • 415 – a good beginner blade, often with pins. It is not a good blade to do accurate work with. I use it only for the first time on the scroll saw blade. It has small teeth, so there is little danger for the many children I have taught on the scroll saw to get seriously cut. It also breaks more often than other blades, which is okay because it teaches them how to put blades on and off the scroll saw.
  • 420 – This is a common pinned blade we use. It has large teeth. We use this when extremely fine work is not required. The edges are not as smooth as the fretwork blades. The teeth on this blade have a large set (the distance the teeth are bent apart) to them then so it can cut thicker materials without bending or twist (as the fret blades often do). This works great on 2×8 material that I use to make piggy banks.
  • 433 – an excellent blade for fine fretwork. I have used this for cutting paper in stacks of 50 sheets or even cardboard. Smaller blades are available for this purpose as well.
  • 443-(TPI-20, Univ.#2) – This blade is excellent for tight corners in 3/8′ oak and such.
  • 446-(TPI 12.5 Univ.# 5) – This blade is excellent for thicker fretwork. I used this blade almost exclusively.
  • 448(TPI 11.5,Univ.#7),450(TPI 11.5 Univ.#9),453(TPI 9.5, Univ.#12) – Is for thicker material. As the numbers get larger, the blade becomes thicker in width and depth, so tight turning becomes increasingly difficult.
  • 454 – I bought some of these blades, and they were expensive, thinking that they would cut even thicker materials. They did not. They twisted and turned even more than the 453 blades.
  • Spiral blades – There are a number of spiral blades. These blades cut in every direction. Their main purpose is to increase the thickness of the cut. The veining is the term used by many. Think of the veins in a leaf. I would often cut a piece of wood with a 433 blade, which gives me great control over where the blade cuts in the piece of wood. The line that is cut is very, very thin. After the work is done, I found that the line was not visible. I would put in a spiral blade and cut this line again. At that point, the cut line was visible on the other side of the room. You cannot control a spiral blade if the line is not cut first with a regular blade. DO NOT USE A SPIRAL BLADE WITHOUT CUTTING IT WITH A NORMAL BLADE. You will not be able to control its direction. An example of the use of spiral blades can be seen on the home page. The hair lines were cut with a 446 and then increased in size with a spiral blade. Please note that there are different sizes of spiral blades with different thicknesses.

Patterns on the Wood

The most important thing to remember is we cut out patterns. Wood is underneath, but we are really only cutting out patterns.

Whatever pattern we use, we must get it to stick on the wood. I have tried many things; tape, double-sided tape, contact cement, spray contact cement.

All of these don’t work well. The only thing I have found to work well is the Spray mount used by photographers. This is a spray that, after it is applied, the picture can be removed again.

A scroll sawer wants a pattern to remain for a time and then remove the pattern.

The only spray I found to work is made by 3M, which was once called spray mount and now called Super 77 spray adhesive.

Still Cutting Just One at a Time?

Why are you cutting out only one piece of wood at a time? Cut out as many as you can. I can cut out eight pieces of paneling at one time.

Some have used nails, but I like saving money, so I use flat headed screws and screw as much material together that I can and cut. When I am finished, I take the screws out.

Drywall screws work the best. The screws either go through the corners of the wood or through the last piece I am going to cut out. Remember, the screws have to be far enough apart to make sure the wood layers don’t shift.

Put in three screws if you are afraid that it might shift. When I am cutting out the oak picture frames, I put together two layers of 3/8″ oak, and I put two screws through the top layer into the bottom layer.

I put the screws through the piece that the picture will be seen through. When I cut out the 3d lions from cardboard for a children’s group, I put many screws into cardboard stacked eight deep.

Whatever you do, stack the wood as much as you can. It saves you time and energy. Remember that you might have to change the type of blade you use, but that is what experience teaches us.

Use of Wax to Cool Scroll Saw Blades

Burnt wood, melting plastic, dull blades are common problems for the scroll sawer. Wax acts like oil on mechanical parts. It reduces friction and cools the parts.

These problems can be solved by slowing down the speed of the scroll saw, but many only have a single speed saw. These problems can be reduced with the use of wax.

Almost all the wax I have seen used goes on the blade, and it helps little. The most important part of scroll sawing is the pattern.

Think pattern and go to your odds and ends drawer. Find that half-burned candle from that romantic meal you had with your wife or husband.

Mount your pattern on the wood. Light the candle (white candles are best because the wax is more see-through). Then let the wax drop onto the pattern, especially where there are sharp turns to be made.

The higher you hold the candle, the more splatter, and the wax is shallower. Experiment to find what works. I would only make a few holes at a time. If you make the entire pattern, to begin with, the wax will get cloudy because of the accumulation of dust.

When it comes to plastics, some plastics will even melt with wax, and the speed has to be reduced. I have cut plexiglass and plastics stacked up to 1 inch thick. Suppose you find that the wax causes you to lose sight of the pattern, you might want to make wax paper with old candles by melting them and dipping the paper into it.

When you stack plastic or wood, you put this wax paper in between the layers. Wax keeps wood from burning, helps you cut through plastic, and increases the length of time you can use your blade before you sharpen it.

Which Way to Turn Blades

The problem with straight lines is they are difficult to cut straight with the scroll saw, but the other problem is which way you should be cutting out a hole? Should I cut it out clockwise(CW) or counterclockwise(CCW)?

The answer is determined by the blades and how they are made. When the blade is installed properly, teeth down, the saw almost always wants to cut to the right. The reason is that the blades are, I believe, punched out of a piece of metal and therefore are sharper on one side than the other.

The right side is sharper than the left. That means if you cut a hole out of wood CCW, it will be much easier. The other point is that if you need to cut out a small hole, CCW is the way to do it.

Stacking, Multiple Layers, and Turning

When you are stacking to cut out multiple copies, you will find that the hole will be a little smaller at the bottom than at the top of the other way around.

If you try to cut CW, the hole on the bottom will get too big, and the bottom piece or pieces might be of no use. If you cut CCW, the hole will become smaller, and it will be usable.

I have worked with slots and tabs like the four-piece lion stand up on the easy page. What I have discovered is that when I have cut eight of these out at once, the bottom one was unusable.

I changed my technique in that I did not cut around the hole. But I cut into the pattern for the slot. I then pulled the blade out and then cut in on the other side, so both sides of the slot were cut from the same direction.

That meant the slot was then the same size at the top as in the bottom.