How to Square Rough Cut Lumber With a Table Saw

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Lumber is like meat.  With meat, the fewer times a butcher needs to touch it with his knife, the cheaper it will be.  But, you’ll have to touch it with your knife when you get it home: breaking down a whole chicken into drumsticks, thighs, and breasts, and using the carcass to make stock for gravy or sauce; or maybe removing the fat cap from a whole sirloin and cutting it into individual steaks for grilling.

You save money on the original buy without having to pay for the butcher’s time and replacing that time with your own butchering skills. With the right tools in your kitchen, a sharp knife, and a cutting board, it’s actually pretty easy.

The same is true for wood.  Buying rough-cut wood that has only been touched once at the sawmill is cheaper than buying dimensional wood from the lumber yard.  So what if it still has a partial “live” edge?  You’re not paying for the extra milling and instead are doing that milling yourself in your home shop.

But, if your power tool inventory is merely a table saw, a chop saw, and a skill saw, can you really do that?  Without a planer, even?  Can you square off that rough-cut lumber into straight edges for jointing?  Sure you can, and we can point you in the right direction with both some thoughts and some helpful videos.

How Do You Square Rough-Cut Lumber?

Nature is not perfect.  Straight and square trees don’t grow, and wood does not dry consistently through and through.  And, it’s not realistic to expect that piece of dimensional board you bought from the lumber yard is square.

Sometimes, you just have to square wood yourself, and if you’ve purchased it directly from the mill after just one cut, this will be essential.  Learning this skill will allow you to make those direct purchases, too, and save you money. Rough-cut stock can run as much as 50% less than S4S (surfaced four sides) stock.

Taking control of the dimensional process in your shop like this can help ensure a better color and grain match if the stock is sawn from the same tree.

Rough Cut Lumber

Select your planks and cross-cut them down to rough lengths to make them easier to work with, as well as to save wood.  Cutting bowed boards down to shorter lengths, for instance, is a more efficient use of the stock than trying to flatten it by other means.

From this point, you have some options to choose from: using a long, metal level; building a sled; or using your skill saw with either a commercial guide or a custom guide you build yourself.

A video demonstration will be more effective at this point than a lot of words, so take a look at this one we found for you.  Watch it and come back for the rest.

You saw in the video the jointed edges lined up tightly, joining the boards without a jointer or a planer.  You also saw the rip fence was not relied upon for those jointed edges.

And as for the ends, measure a couple of times, and make sure your chop saw is square.  In fact, double-check your chop saw is square.  Use a stop block or clamp, too, as an added measure of stability during the cut.  Maybe, even, use both.

The running board length will be straight and smooth, and any crooked edge has been made square.

Following this process will answer the questions:

  • What can I use if I don’t have a jointer?; and,
  • What’s the best way to square up a board?

Remember that you’ve saved money buying directly from the sawmill.  This means you have to do a bit of extra work to get the pieces you need for your project.  There is a price in labor and additional steps for taking control of the dimensional process in your home shop.  That also means you can ensure you’ll get precisely what your project needs.

What About Squaring a 2×4?

Actually, this is a pretty easy task.  No jointer?  No problem.  It takes only a couple of steps and just a few minutes.

Cutting the 2×4 to length first will help with the rest of the steps.  After cutting to length for your project, position your rip fence 3 ¼” from the inside of the table saw blade.  With a blade guard in place, rip one edge of the 2×4.

Then, set the rip fence to 3” from the inside of the blade, flip the 2×4, and hold the already-ripped edge against it.  Rip the other side, and you have a squared 2×4.  You will have lost ½’ of it, yes, but it will be square.  So, simply adjust the dimensions of the rest of the pieces for your project accordingly. 

What About Squaring a 2x4

In this instance, as in most others, being square is more important than dimension, as you can simply adjust your project plan accordingly.

Zero Clearance Inserts

If you’re going to be doing this extra work, you’ll be creating small pieces or strips of wood as you square up your board edge and dimensional sides.  Your table saw is going to need a bit of protection from these small pieces and strips, and so will you.

What is zero clearance?  It refers specifically to a table saw insert that minimizes the size of your saw’s blade opening.  It reduces the chances of a tear-out on your cuts and prevents those small pieces and strips from falling into the blade well.  This, in turn, helps prevent kickback and injury.

These inserts are often made with Phenolic, a material of layers of paper, cotton, or glass fiber under high pressure and heat to which a synthetic resin is added as filler.  It’s a very tough but lightweight material and serves the purpose of a zero-clearance insert well.

The slit through which the table saw blade rises is cut specifically to the blade’s kerf, and it provides an otherwise impenetrable surface flush with the saw’s table.  It works with the 90 degrees of the blade to the table’s surface; a separate insert would be needed for 45-degree cuts.

In the process of squaring rough-cut lumber with your table saw, as we said, there will be little pieces and strips being cut, and you want them to remain on the surface for clearing, rather than down in the blade well.  The zero-clearance insert helps keep them where you want them.

Saving a bit of money, upwards of half the cost of dimensional lumber, and using creative workarounds for a home shop with only the basic power tools, is a pretty cool thing.  You ensure you get exactly what you need for that project and have fun in the process. 

The pleasure of woodworking, like life, is in the process.  Yes, the end result is a nice piece of furniture or a lovely new dining room table.  But, the fun you’ll have in making them is worth the extra time and effort.

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