In this instructable I'll be comparing three methods of resawing that I've learned and observed working at Techshop, San Francisco: resawing on the bandsaw with a tall fence, resawing freehand on the bandsaw, and resawing on the table saw.
Just for good measure, I also found a walkthough on how to resaw a board with a handsaw. I'll stick to power tools for this task since I have access to them, but I always admire those who work with hand tools.
As always, I'm still a relative newcomer to woodworking - if anyone has any corrections or additional information, please share it in the comments. Just keep the criticism constructive.
Step 1: What is resawing, and why should I do it?
- Rip cuts are the most common cuts on the table saw, and involve cutting along the length of the board with the grain of the wood, splitting a larger board into narrower sections.
- Cross cuts are also very common, and just like the name implies they involve cutting across the grain of the wood, shortening the length of the board.
- Re-sawing is a bit less common, but very useful for certain applications. It's like a rip cut, with a twist - it involves ripping straight through the center of a board the thick way, producing two thinner boards.
Reasons to re-saw
Save money and materialImagine I have a bunch of 1" thick boards, but my project only calls for 3/8" thick lumber. I could go out and buy some pre-milled thin lumber (which is expensive) or I could sacrifice 5/8" of my current boards by milling them down to size (turning good wood into sawdust). Neither is a good option, but by resawing my wood I can go ahead and use my rough-cut lumber, and end up with twice as much 3/8" wood. That's a good deal!
Book-matching, other grain effectsHave you ever seen nice furniture where all the front panels have matching or complementary grain patterns? How about a nice guitar top with perfectly symmetrical sides? Or a wooden box where the wood grain lines wrap completely around all four sides? Resawing is one way you can create those effects. When you cut a board down the middle, you will have 2 pieces that are almost mirror images of each other.
Make your own veneersThere's no need to stop at cutting a board in half. When you slice off very thin sections (1/8" or less) you are basically creating your own veneers. This can be quite useful for creating interesting grain patterns, like I mentioned above. But it can also be useful for stretching the usefulness of very rare or expensive pieces of lumber.
Also, with store-bought veneers, you only have 1/32" of wood to work with, and if you're not careful you can burn straight through them while sanding, scraping or planing. By making your own veneers, you can start by making them extra thick, then plane or sand them down as thin as you want.
So that's why you should learn how to resaw. Next I'll show you how I 've done it.
Methods - advantages and disadvantages
- Bandsaws are the most common tools for re-sawing. They are useful because they can handle almost any standard size board, and can even be used to resaw whole logs. Bandsaw resawing can be difficult for beginners to master, but a properly tuned bandsaw can greatly improve the process.
- Table saws are useful for resawing narrow boards. The biggest advantage of table saws is that they produce very clean, repeatable cuts. It's easy for beginners to get started, because resawing is just like rip cutting, but with thicker wood.
- However, as always, table saws are one of the most dangerous tools in the shop - and resawing is no exception. Resawing carries a higher risk of kickback than rip cutting, if the board tips away from the blade or falls into the blade after finishing the cut.
Image attributionPhotos found through google image search
Step 2: Tools and materials
- Table Saw
- Jointer & Planer OR handplanes
- (Optional) Grr-ripper push-block
- (Optional) Tall resaw fence for the bandsaw - described in a separate instructable
- (Optional) - 4X4 with square, jointed sides
*Note on bandsaw blade. I've gotten best results from using an extra wide resaw blade. Since Techshop provides the blades, I go ahead and use theirs. For woodworkers on a budget, you can also use more general purpose blades to resaw, but it takes some more work and patience to get a nice, straight cut. I'll explain more about blade choice in the next step.
- Peruvian walnut and cherry wood ~ 1" thick, 7" wide, 26" long boards. If using rough cut lumber I joint and plane it before resawing because it makes cleanup easier later, and I can know exactly how much good wood I have to work with.
- (Optional) Double stick tape
Step 3: Setting up the bandsaw
For both these reasons, it's a good idea to run a few diagnostic tests. You should check; the blade itself, blade tracking, blade tension, the guide bearings, and the fence.
There are special resaw blades available that make the process a lot easier. These blades are extra wide, so they don't bend much while you're cutting. They also have sharp teeth in a "skip tooth" or "hook tooth" arrangement that can quickly clear sawdust out of the saw cut, allowing you to cut more quickly. Techshop stocks these blades, so that's what I use on my resaw cuts. I usually wait until I have a few projects that require resawing, then ask a staff member to change the blades for me.
However, if you can't afford to buy specialty blades, or you just don't want to bother changing blades to make a few cuts, you can also use a much thinner blades. In fact, I've read articles from many woodworking professionals that say they use the same exact blade for almost all their bandsaw cuts. Fine Woodworking magazine (online subscription required to view articles) has several great articles and videos about resawing. All their experts I read recommend a 1/2" wide blade, measuring ~0.025" thick, with a "skip tooth" or "hook tooth" pattern and 3 TPI (teeth per inch). This is a somewhat coarse blade, but it can do a bit of everything from resawing to straight cuts and wide curve cuts. It's a good general purpose blade to keep on the saw.
Check that the teeth are sharp and that the weld spot where the blade loops together is clean. This is a good idea for any type of work on the bandsaw, but with resawing you will be cutting through so much wood that dull, clogged teeth or a messy weld will show up more easily.
You want to make sure that the blade is centered when rotating on the pulleys, not waving back and forth. Open up the top of the saw and spin the wheel by hand, keeping an eye on the blade. It should stay centered on the wheel tread. Now turn the saw on and watch the blade - it should go straight down through the throat of the saw with no visible wavering.
The blade needs to be nice and tight for resaw work. Technically, blades should be set anywhere from 7,000 - 15,000 PSI, depending on the saw. Most bandsaws have a rough tension gauge, but these are notoriously unreliable and imprecise. I don't keep a $300 tensiometer in my back pocket, so in practice the tension can be checked by feel or by sound. Just pluck an open section of the blade and feel how tense it is or listen to the sound it makes. A well tensioned blade should resonate a bit like a guitar string - one article I read said it should sound like the "E" on a bass guitar.
If you're new to the bandsaw, don't worry about being so precise right away, but take a minute to check the machine's condition when you work on it. Pay special attention to the machine when you make really good cuts and really bad cuts, and over time you'll develop a sense of what feels right and sounds right.
There are many styles of blade guide, from roller bearings like Techshop SF's setup, to flat pieces of steel and hardened plastic. Whatever your system, it will typically include side and rear guides to keep the blade from moving during cuts. For resawing, these guides should be set very close to the blade - a rule of thumb is that you should JUST be able to slip a piece of paper between the blades and the guides.
Once you check all these factors, make a test cut on some scrap wood. Check that the blade is cutting a straight line, not curving in and out of the cut, and make sure the fence is set up to make even cuts along the length of the board. Once you are happy with the results, it's time to resaw.
Step 4: Resawing on the bandsaw 1 - Using a fence
When using any kind of fence, it's important to watch your feed rate while cutting. Pushing too fast can make the blade buckle even more when sawdust builds up too quickly. Keep it slow and steady to keep a good, straight cut.
- Set the desired width of cut. The boards I'm using are 0.90 inches after jointing and planing, and I want two 3/8" boards at the end, so I cut them exactly in half at 0.45", measured with a pair of calipers. You can also use a ruler or square, I just like to use calipers.
- If using a tall fence, register it against the stock fence. The stock fence of a bandsaw should already be set to compensate for the drift angle* of the bandsaw. Instead of re-skewing this angle for the tall fence, just set it square against the stock fence.
- Use clamps to secure the tall fence to the table
- Turn the bandsaw on and let it come up to full speed, then slowly and steadily push through the cut. Watch the blade carefully to stay safe and to check if the cut is on track.
- Keep one hand in back, pushing the wood through the cut, and keep the other hand on the side of the board, applying even pressure against the fence. I like to use a grippy push-block for this job.
- Gary Rogowski of Fine WoodWorking Magazine said "You can cut fast, or you can cut straight. I prefer to cut straight." It really is important to go slower than usual while resawing. If you go too fast, sawdust builds up in the cut and pushes the blade to the side, creating a wavy S-shaped cut. Matthias of woodgears.ca has a great explanation of what goes on inside of a bandsaw cut.
- If the board is longer than the bandsaw table, it's a good idea to have in-feed / out-feed rollers or other supports for the board, so it doesn't unexpectedly tip over mid-cut.
- For long boards, it's also good to switch from pushing to pulling the board through the cur, just for the last inch or so of the cut.
- If pushing through the end of the cut, get your hand away from the back before the blade pops out! Use scrap wood or a push stick for the last inch or so of the cut.
Step 5: Resawing on the bandsaw 2 - Freehand
To give some extra stability to this freehand cut, a fellow Techshop member recommended attaching a wider piece of wood to the base of the wood being cut. For this test I decided to use an identical piece of Peruvian walnut to the one cut with the tall fence, attached to a 4X4 with two jointed and square sides with double stick carpet tape.
All the same rules apply to this cut as when using a fence. Let the bandsaw come up to speed, start slow and maintain a steady rate. Without the fence, you have to be extra careful about the blade wandering - but the 4X4 does help a lot.
- Gather the piece of wood you want to cut, a 4X4 jointed flat on at least two sides, and a piece of double stick tape or spray mount.
- Stick the 4X4 to one flat and square face of the wood to be cut using the double stick tape or spray mount
- Draw a line down the center of the wood where you want to cut it. Remember to allow a little extra space for the saw blade and any cutting errors.
- Start the cut along the line, and keep a slow, steady pace through the cut. It's important not to go too fast when resawing. Woodworker Gary Rogowski said in a Fine WoodWorking Magazine video "You can cut fast, or you can cut straight. I prefer to cut straight." Cutting too fast causes sawdust to build up in the cut, and when the blade can't clear sawdust away it gets pushed right or left, creating a wavy cut. If your cut starts to look "S" shaped, try slowing down.
- When you reach the last few inches of the cut, be careful to keep your hand away from the exit path of the blade. If you are pushing from the back, put your hand on the 4X4 instead of the workpiece, or use a push-stick to support it from the back.
- For long pieces of wood, it can be good to pause near the end of the cut, and switch from pushing the board to pulling the board. This gets your hands well out of the danger zone, and also lets you support the board from falling off the end of the bandsaw table.
- After cutting, you can run the wood over the jointer or planer to get it perfectly flat again.
In the last picture, you can see both bandsaw cuts side by side. Both worked pretty well, but the tall fence was a bit more consistent. The one cut on the fence varies by less than 0.02" across the whole board. The one cut freehand was mostly good, but I let it wander in a couple spots. Still, both of them will give me enough material for two 3/8 inch boards even after going through the planer. Also, I've only tried freehand cutting a few times, and I expect my results could improve with practice.
Step 6: Resawing on the table saw
For anything narrower than a standard table saw blade's depth of cut (~3" inches) resawing work just like rip cutting. Raise the blade just above the material, then push it through. The only thing to keep in mind is that if the board is thinner than it is wide, the cut may be a little unstable - carrying an increased risk of kickback.
To increase safety, you can put feather boards before and/or after the blade, to help guide the board through the cut. The feather boards should have almost zero pressure against the board, they are only there to help guide it through. Never put featherboards next to the blade, only before or after the blade.
Boards up to 6" inches wide
For boards that are wider than 3" cut of the table saw, you can push them through with the blade fully buried in the wood. After the first pass, flip the board end-over-end and cut the rest of the material. One thing to watch for is that as you cut through the material, the gap between the two halves will want to close in and pinch the blade, which can cause kickback.
A cut like this can't be made using a blade guard - you'll have to remove it to make the cut. In place of a blade guard, you can use something called a riving knife - a piece of metal the same width as the blade that sits just behind the blade. The riving knife helps prevent the board from pinching the blade after it's cut by spreading the halves apart.
Riving knives are good, but for another layer of safety you can add one more step, which also works for boards over 6" wide...
Boards over 6" inches wide
Wider boards can't be cut entirely on the table saw, but you can use the table saw to start the resaw cut, and finish up with another tool. That's what I did for my board in this instructable. My board was ~7" wide, so even after cutting both sides I had a 1" strip left over in the center. To finish up the job I left that 1" strip in place and moved back to the bandsaw to finish the cut. For those without a bandsaw, you can also use a handsaw to finish up this cut - just clamp the board in a vise and carefully saw through the table saw kerf.
It may seem redundant to use two tools to make one cut, but there are good reasons to do so. In this example it was much, MUCH easier to use the bandsaw on just the 1" strip as opposed to a whole 7" of wood. A normal bandsaw cut can take a few minutes, and it takes some muscle and concentration to get a good result. But cutting that 1" strip took literally a few seconds. And although the strip in the middle is uneven after cutting, the rest of the table saw cut is very clean and precise - this board cleaned up very quickly on the planer, and I could have easily cleaned it up with a hand plane as well.
Extra safety tips
- For extra long boards, it's a good idea to use infeed rollers and an out feed table to keep the board stable during the beginning and end of the cut
- For cutting very thin pieces (less than 1/4") it's a good idea to cut them on the outside "waste" side of the saw, away from the fence, using the feather-board to measure the cut. This is because it can be dangerous to pinch very thin pieces between blade and fence.
- Avoid pausing mid cut, for example to adjust your grip. Doing so is relatively safe during a normal rip cut, but carries extra risk when resawing, because there is much more wood that can potentially catch the blade if you loosen your grip. Try to make a smooth, steady cut throughout the length of the board.
Step 7: Clean up on the planer
- Even straight boards can have different areas of tension inside of them that cancel each-other out while the board is whole. But when you cut it, that tension gets released, pulling the board out of square.
- Also, any time a board is freshly milled or cut, there is a change in moisture content. In this case, the difference in moisture between the outside and freshly cut inside of the board may cause the board to cup or bow.
If you're resawing to create a bookmatch or "four-corner-matched" box, be very careful when flattening the boards - planing away too much material can ruin the bookmatch.
- If you're just cleaning up saw marks you can start by lightly running the board over the jointer, instead of planing the freshly resawn faces. Take very light cuts, ~1/32" or less, to preserve the most material on the inside faces. After jointing away the saw marks, any remaining flaws can be fixed with sanding.
- After jointing the inside faces, if you want to plane for thickness, flip the boards over and plane the old outside faces of the boards. This will let you achieve the thickness desired without changing the bookmatched patterns.
- If you are resawing multiple thin pieces off a large piece of wood, it's a good idea to run the sawn face of the larger piece over the jointer between each resawing. That way each freshly cut piece will have at least one flat reference face when running through the planer.