Woodworking: How to saw to a straight line?

I have been watching some woodworking videos on YouTube and am in awe of the ability of some woodworkers to be able to draw a straight line on both sides of a board and then saw to that line on both sides. Whenever I try to do it, my cuts are always off by a degree or two which is quickly amplified as I cut. I know about starting the cut by placing your thumb next to the blade and so on, but so far, I haven’t been able to do it. Is it just a matter of lots of practice until you get a feel for it? Is it the quality of tool or how well it’s sharpened?

I have the same problem hacksawing metal.

(For extra credit, is there a trick to truing up a board only using handplanes?)


Why are they drawing a line on both sides?

Yes, it’s practice. Your stance has to be right, find a natural stance where your arm can move back and forth smoothly. The wood should be waist height or lower. The saw has to be sharp also to prevent excess vibration and catching. Your motion should be smooth. Just keep practicing. It helps if you start when you’re a little kid. The type of wood, board dimensions, and type of saw make a difference too.

Hacksawing can be more difficult. The blade doesn’t cut much on each stroke. You can hold the other end of the saw to get things started, and keep it lubricated so it will cut well.

Planing a board is a matter of roughing and then finishing. Sight down the all sides of the board and lay it on flat surfaces and straight edges to find all the ways it’s off. Mark the areas where wood has to be removed. Use a knife to score it where you need to remove a lot of wood, use a pencil or chalk where less removal is needed. Clamp the wood down well, and on each side use the plane to rough down the excess wood. Don’t overdo it, you may need to stop and remark it again. Once it’s close to square and flat all around, just plane down each side with the plate flat against the wood.

I haven’t hand planed a board in years. Power tools are wonderful.

Practice, high-quality tools and high-quality wood.

For things like tenons.

How do you test whether the two faces are parallel? With a try square?

Hand-sawing is an art and it takes practice. As for correcting your cut: the intuitive thing to do is to bend the blade to correct your cut line. Most people’s intuition on this is exactly backwards. Putting pressure on the handle to the right does not make the blade correct to the left. A good quality saw helps a lot, and you can spend a lot on them. I bought my dovetail saw from Lie-Nielson, as it comes already set to rip pattern and has a reinforced back.

For planing, try to find a vintage Stanley plane (probably about $30-40 in an antique shop), then replace the blade with a newer A2 blade and cap iron. This will help reduce blade chatter. The newer Stanleys are hit or miss. The old ones (around 1950 and earlier) were made in the USA and are a solid chunk of steel. New top-quality planes (Lie-Nielson, Veritas, etc.) are very expensive, and I wouldn’t go there unless you have money to burn. There are all kinds of videos for tuning up your plane. Tripolar has it right for truing up a piece of wood; also about power tools like surfacers being the wonders of our age.

Ok, they might not of shown you where they selected good straight grain for the tenon area. That makes the ripping cuts stay nice and straight. The cross cuts to finish are shorter and simpler. The marking on both sides is also because there’s often some clean up work afterwards, they may not be showing you often that happens. Tenon saws should be light and easy to control with wrist.

Yes, once you have one side flat you can lay it down on a level surface and slide a square, or just a squared block of wood along the length. You can hold another straight edge against your tool with thumb and finger and feel for any wobble as it passes over. You can also mark lines on adjacent sides with your square after flattening one side. Or use a carpenter’s marking gauge to do that. If you have good square right angle fence on your workbench, like a square block of wood, or a piece of angle iron, you can plane the board to get right angles all around and the opposite faces will be parallel. That’s what you end up doing if you use a joiner.

Ahem. Can I say here you are both making me hot under the collar? (Not to mention other places.)

Carry on, please.

Mortise, meet tenon.

Selecting wood is an art form. Take a board and get to know it, take your time, run your fingers down the length to feel the grain. Smell the wood, look for the gentle curves in the grain, lay it gently on your workbench…

A long plane is better for truing boards than a short one - which can end up amplifying cups and bends - whereas a longer one will ride over bumps and straighten the profile of the board as a whole.
Place pressure on the front handle of the plane when starting, and transfer pressure gradually to the other hand during the stroke.

On sawing, it may be that you (the OP) are just trying too hard. As others have said, stance, quality of tools, etc all make a lot of difference, but also, if you try to rush the cut by pressing too hard, that’s a sure way to swerve off course. You almost need to let the weight of the tool do the cutting (almost)

One trick, if you have a decent flat workbench, is to pounce chalkdust or lampblack onto it, then lay your rough board on it. Anything that gets marked, you plane down.

Aah! I’ll try that next time! :slight_smile:

There are 3 kinds of straight in woodworking:

Rough carpentry straight
Finish carpentry straight
Furniture straight

For the first two, practice makes fairly perfect. For furniture, I prefer the help of a straight edge to guide the cut either with a table saw/fence or other type of straight edge if using a circular, band or jig saw.

If you really, really want an accurate cut to a scribed line, then you don’t use a pencil to mark the wood in the first place …you use a **marking knife **to cut the line on the wood, and saw to that. You can go one step further by using a sharp chisel to cut out a shallow “V” on the waste side of the line, and that V groove will guide your saw.

If you are cutting a tenon, you make a shallow cut on the face side first, then a shallow cut on the face edge to the depth of the cheek of the tenon, and do the same on the other side. This way, it is practically impossible to end up with an out of square cut, if your measurement is accurate to start with, and if your saw is in good condition in every respect.

I use a Japanese style pull saw whenever possible. It cuts much more precisely, and I mark all four sides of my wood.

If I start on two lines, and check a few times, I can get a pretty precise cut. By the time I am through to the bottom, I have a good guide slot. After that, I just take it easy and it stays on course.

When cutting a straight line with the home style bandsaws the trick is to find out the angle your saw actually cuts at then adjust your fence accordingly. I draw a line on a board similar to the one I will be cutting and then run the board through by hand noting the angle I am pushing it through to achieve a straight cut, it may be off by 5 degrees of so. I then adjust my fence to this same angle and I achieve extremely smooth, clean accurate cuts this way. Great tip for resawing, explained in more detail in any good resaw book.

The Woodwright’s Shop,
Sawing Secrets
Hand Plane Essentials


I just saw a woodworking show where they cut tenons for a workbench. They showed how they had to clean up with a plane after the cuts, and there initial work with the saw was done outside of the markings. But I do all these cuts now using a bandsaw and finishing with a belt and disk sander. It is so much easier that way.

For a few years on NCIS, Gibbs was building a boat in his basement, using hand tools only. During one episode he shows girlfriend how to plane a timber. He stands behind her (close behind her!) and guides her hand with the plane, saying as he did so, “Feel the wood”.

Given how he was standing, I am quite certain that she could, indeed, feel the wood.