Through the years I have dulled a lot of bandsaw blades on my sawmill, and for the longest time, I have struggled with keeping them sharp. I have tried multiple tools and methods to get this done, but only within the last year do I feel like I have found a good solution.
The problem starts with the bandsaw blade itself. It is a finicky conglomeration of bent teeth, cut from a thin piece of flexible steel that is somehow supposed to cut a straight line, not only from front to back, but also side to side, and if it isn’t well machined and sharp, there isn’t a snowball’s chance that this is going to happen.
Early in my career, when a new saw blade dulled and started to cut waves, I would try things like adding tension to the blade, slowing down my feed rate or even adjusting my blade guides. No matter what I tried, a dull blade would still make a wavy cut. However, if I used the exact same setup but installed a new blade, the cut would be perfect again. As a matter of fact, almost every other adjustment could be less than perfect and a sharp blade would still make a good cut. From 15 years of experience, it is clear that I need to keep my saw blade sharp and touch nothing else.
My standard course of action is to put on a new or newly sharpened blade from Wood-Mizer when my cut starts getting wavy. This is a great way to live. Nothing cuts like a brand new blade, and it feels like a treat to put one on. Even the resharpened blades cut great since they get a complete factory treatment, including cleaning and full tooth grinding and setting. I have always had great results from Wood-Mizer, and I highly recommend their new blades and resharpening service. (Disclaimer: I am not being paid by Wood-Mizer and Wood-Mizer doesn’t know I’m writing this post – they probably don’t even know I exist.)
The problem for me was that time in between cutting like new and cutting like crap. I would have a blade that was cutting great, but I could feel it pulling hard and on the verge of cutting poorly. I didn’t want to pull it off of the saw because it was running so well, but at the same time I knew my time was limited. If I could just get an edge back, I could keep cutting with the same blade and not have to mess with sending the blade off to be sharpened, and I would save $7 (by the way, I think $7 is a great price for the quality of service, but I would rather not spend it if I don’t have to). So, off I went, looking for a way to sharpen blades on my own.
In the past, I tried using a manual sharpener that came with my first bandsaw mill. It functioned like it was designed to, but the results weren’t great. Besides having to take the blade off of the mill and set it up in the sharpener, it used a stone that wore down quickly and wouldn’t maintain a flat, consistent face on the tooth (looking back, I probably should have tried some other stone options, but I didn’t).
Later, I tried a few other approaches. The first was using my chainsaw grinder, like the one below, which had a similar problem to the first grinder. The small stones would wear down quickly and the thin bandsaw blade would basically cut the stones in half.
The next attempt used a sanding disc on a drill. I liked the idea of using sandpaper because it maintained a flat surface during grinding – it would wear down, but not change shape. This one showed potential, but it was incredibly hard to control because the spinning motion pulled the drill up and away from the blade.
I finally gave up, feeling like I had exhausted every option cheaper than buying a fully automatic grinder like the factory has, but I never gave up on the idea of sandpaper as a good abrasive that doesn’t change shape.
Up to that point, all of my attempts focused on sharpening the saw by grinding the front of the tooth. There was nothing else I could think of that would fit between the teeth and grind the front of them. But, then I thought about grinding the top of the teeth. This surface is easier to get to and taking material off of the top will still lead to a sharp point – it doesn’t really matter which face gets ground down.
I started off with my 3″ Porter-Cable belt sander just to try things out and it worked great. I could sand the top edge of the tooth with control and the speed was slow enough to not feel like I was burning the metal (which softens the teeth). The only problem was the weight of the belt sander, which might as well have been 1,000 lbs. because there was no way I could hold it to sharpen all of the teeth on the blade.
At the time I didn’t own a small belt sander, so I took a gamble and purchased a Porter-Cable 371 compact belt sander. I figured that even if it didn’t work for the blade sharpening I would at least have another tool in my woodworking arsenal and that there were going to be plenty of times when a small belt sander would come in handy. Finding other uses for the new sander hasn’t been much of an issue though, because it works great to sharpen blades, and it is always parked (plugged in) right next to my saw, ready for the next dull one to come along.
I simply leave the blade on the saw and grind just enough off of the top of each tooth to get the edge back. I use my free hand to steady the blade and to advance the saw to the next tooth. In a matter of just a few minutes I can be back to cutting, feeling like I have beat the system.
Now, there are limits to sharpening your saw like this. First off, no matter how good you get with the sander, the blade will not be as good as a new one or one that has had a full factory grind and set because this grinding is changing the geometry of the already finicky blade. And, it will do nothing to improve a blade that was just generally running badly or running badly for a specific reason like hitting a rock or metal (all of these problem blades get sent out for a full resharpening). It will, however, make a blade that was running well continue to run well and make flat, straight cuts for much longer.
Generally, it seems to work out that I touch up a blade with the sander a time or two and then send it out for full service or, for some of them, they keep working great and I keep sharpening them with the sander until they break. For all of the others, I hit something along the way (dirt, rocks, concrete, nails, hooks, cable, wire, screw-eyes, barbed wire, fence posts, screws, license plates, horseshoes, railroad spikes, chain, conduit, hangers) that either destroys the blade or dulls it enough that it needs a full regrind.
Even if I don’t use this method all of the time, it is nice to have another option to get back to cutting. If nothing else, I personally love the comfort of knowing that when I get down to my last new blade (and forgot for the second week in a row to order new ones) that I won’t be stuck cutting wavy lumber.
If you have driven down Highway 40 in St. Louis recently, you may have noticed a new structure being erected next to the St. Louis Science Center where the “temporary” Exploradome once stood. After 16 years in service, the inflated building was past its prime and too expensive to operate, so it was replaced with a new, permanent agriculture exhibit called Grow.
The centerpiece of the exhibit is the new building that features massive bent laminated beams which create a beautiful swoosh of a roof. Just outside the entrance of the new building is a vermiculture display that I built for the exhibit. While it pales in comparison to the woodwork that went into making the building, I like to think it makes a nice little earth-friendly welcome mat for visitors.
The vermiculture unit, designed by Mark Cooley, uses worms to make compost. Built out of locally salvaged Eastern Red Cedar, the two-compartment structure is set up to have green waste loaded in the top and compost extracted from the bottom after the worms have done their job eating the contents. The two compartments, which are side by side, are divided by a wire mesh that allows the worms to move between compartments. This particular unit has glass panels to allow for viewing of the interior from the front of the display, though the glass is not required for use.
This project was a bit out of the norm for me since it was more carpentry than fine woodworking, but it was a fun change to build something that wasn’t so fussy. I had the most fun when I was able to find some logs in my shop already standing against the wall for the project. They were left over from another project, and I was able to just carry them to the sawmill and cut the parts I needed. I chuckled to myself while I was doing it because I have never just hand carried logs to the sawmill that were standing in the shop like sticks of lumber. It was only possible because cedar is lightweight and the logs were small, but I still had more than enough to make this project.
Cedar mills like butter on the sawmill, even when dry, and since it was going outside I didn’t need to do any extra drying. I was able to mill it, plane it and assemble it right away, which made it feel more like I was building a fort or a treehouse, especially since I never get to knock something out like that. It reminded me a lot of the Mermaid Lagoon sign I made for Mira a few years ago, since both went together expeditiously. There were a few critical measurements to maintain, like the size of the footprint, but everything else was somewhat negotiable as long as it looked and worked like Mark Cooley’s design.
The vermiculture unit is nestled in the Grow exhibit along a mulch path surrounded by plantings that are arranged like a garden or small farm field. Nearby are live chickens, two new tractors, a greenhouse and a dairy demonstration area. Inside the building are electronic, hands-on displays that focus more on the places that generate food, from the species of plants to different farm settings. Outside, on the North side of the building, are a couple of displays that focus on water, with a chance for the kids to interact with displays that are both hands-on and hands-wet.
The St. Louis Science Center and the new Grow exhibit are free to all visitors. It opens Monday-Saturday at 9:30 a.m. and Sunday at 11:00 a.m. The Science Center closes at 5:30 p.m. during peak summer hours (May 28-Sep. 5, 2016) and at 4:30 p.m. during off-peak hours.
When customers stop by to peruse the lumber and slabs I have for sale, they inevitably end up near the back of my shop, where I do my woodworking. They like to see what I am up to and discuss woodworking in general. Lately, I have been making a lot of live-edge tops, so I usually have at least one being glued up, and I can guarantee you that the first question is going to be, “What do you use to join those two pieces of wood together?” They are expecting a dramatic answer full of technical jargon, like tongue and groove or sliding dovetail or dominos or even biscuits, but I always disappoint them and just say, “glue”. I like to say it in a sort of caveman fashion for dramatic effect and a bit of humor, but then I quickly jump in and fill the awkward silence with a more detailed explanation, especially since I can tell that just blurting out the word “glue” isn’t going to be enough.
I use Titebond original wood glue with the red cap. There is Titebond II and III for more water-resistency, but I usually stick to the original unless it is a project that is prone to getting very wet. I like that the original cleans up easily with water and that even dried glue can be soaked and removed from brushes and clothing. I don’t prefer Titebond for any special reason, except that it is widely used and widely available. I would just as confidently use other name-brand wood glues and expect similar results.
The glues available today are strong, super strong, stronger than the wood itself. To prove this, I always save the end cuts from my glue-ups, so I can break them later for demonstration purposes for customers and inspection purposes for myself. If the glue is fully dry (results are not guaranteed if the glue is still wet), the glued-up scraps will always break somewhere in the wood. Even if it does happen to spilt close to the glue line, there is always plenty of wood stuck to the glue to make anyone doubting the strength of the joint to become a believer.
In comparison, I have worked with plenty of reclaimed wood, especially old oak church pews, that have a tendency to split along the glue joints. When closely inspected, it is clear that the old glue had become dry and brittle, and though it stuck to both surfaces, the glue itself broke down, like old plastic that has been outside too long. Most likely, the older glues, while strong at the time, weren’t formulated correctly to stay flexible over time. Current glues are formulated to hold strong and not break down during regular indoor use. Note that I wrote “indoor” use – for outdoor use, all bets are off. From extreme wood movement to glue breakdown, there is simply too much wear and tear outdoors for the glue to hold a jointed edge together on its own without any eventual failures.
So, we know that the glue is strong and is more than capable of holding a joint together, but just how strong is it? There is probably some value on some fancy scale to tell you exactly how strong the joint is, but it doesn’t really matter, as long as you know that it is stronger than the wood. At that point, to know the strength for sure, you would need to know the strength not only of the wood you are working with, but the weakest point in any given spot in a board, which you just can’t know, so I say stop worrying about it. Just know that it is more than strong enough to do the job.
Now, for the glue to work correctly, your machining and joints need to be reasonably good. I say, “reasonably” good because I think there is a lot of wiggle room here. Obviously, if everything is perfectly square and straight, there is no question about your joint integrity. You can simply coat the joint with glue, apply just enough pressure to pull everything together, and you will end up with a strong, wonderfully impressive joint. But, what if your jointed edges are square but the boards are long and have a bit of a bow and they will require a bit of extra clamp pressure to pull them together, is that gonna work? Heck yeah! Did I mention the glue is strong? A little extra clamp pressure is fine.
What about a lot of clamp pressure? Now this is where the “reasonably” good part comes into play. I say if you are doing a glue-up and you feel like you have applied so much pressure to pull things together that it just feels wrong, then you should probably work on the joint some more. But, here’s the kicker. I can tell you that I have been involved in more glue-ups than I should admit to that have required an inordinate amount of clamp pressure, and to this day (knock on wood), I have never had a joint fail. Maybe I have just been lucky, since I have done tons of glue-ups, but I use this as a real world testament to the strength of the current glues.
The problem with needing a lot of clamp pressure to pull joints together is two-fold. The first issue is that there are built-in forces that are always trying open the joint with the same amount of pressure it took to close up the joint, which can be significant. The other issue, and the one that is commonly more worrisome, is that more clamp pressure means less glue in the joint. The concern being that if all of the glue is squeezed out then obviously there is nothing to hold the wood together. As far as I can tell, especially since I have not had a failure yet, is that this isn’t easily accomplished. I am not saying it isn’t possible, but it isn’t easy. Many woods have open pores that will hold glue no matter how much pressure you give them (think oak and walnut), and if you are fighting at all to pull a joint together, that means that somewhere along the line things are loose enough to hold some glue. Sure, it might completely squeeze out in one spot and make the joint a bit weaker, but in other spots the glue will hold like it is supposed to and keep things from coming apart.
With all of this cavalier talk about crappy joints with extra clamp pressure, you still have to show some restraint. There are going to be times when you can’t rely on just the glue, no matter how strong it is, to hold everything together and you will need to rework your joints for a better fit. A couple of instances come to mind. Some woods have very tight grain that is smooth and won’t hold much glue (think hard maple), so it is possible to end up with a joint that has almost no glue in it. The second instance where more jointing work will be required is if the boards are tight in the middle and loose on the ends. The ends are where a top will want to naturally split, so trying to use extra pressure in this case, is inviting an issue down the road. I feel a million times more confident closing up a gap in the middle of a glue-up than I do the ends, knowing that the entire joint is holding things together, not just the glue on the ends.
One last category that requires a little extra attention is exotic wood. Some have oils in them that just won’t glue properly. They need to be cleaned with lacquer thinner before gluing to provide a good surface and they are often extra hard, so they don’t absorb much glue. I have had problems with bloodwood in the past, which fell apart during my initial tests because I had not cleaned the wood enough. To be safe, I cleaned the wood even more and roughed up the surface a bit with sandpaper to give the glue something to grab. Before the sanding, the edges were just too hard and too smooth. Since then, the extra hard and oily exotics scare me, so I would never force a glue joint with them. I trust the current glues a lot, but there are limits.
Assuming that you have decent joints and wood that will accept glue, all you have to do is make sure that both surfaces are coated with wood glue and clamp them together until the seam is tight. That is really all there is to it and all that is done at almost every professional shop I can think of. You don’t need any special tricks at all, just “glue,” I remind you in my caveman voice.
In the normal course of my business, I am sometimes asked to make flooring out of my customers’ logs. Because I mill the logs into random width boards, I would often get stuck with trying to determine the best width to make the flooring, knowing that no single width would have that great of a yield. No matter the width I chose, there would always be plenty of boards with lots of waste. If I chose 3″ wide flooring, I can guarantee you that an astonishing number of the rough cut boards would just happen to measure 8-3/4″ wide, which would yield two 3″ wide boards and one wide scrap piece, absolutely killing me.
In the past, I have tried to decide the width ahead of milling the logs and pick out which cut was going to be flooring and which was going to be another product, like siding. It seemed simple enough, if the board I was cutting was long and clear with no knot holes, I would cut siding, and if it was knotty and was going to produce only short pieces that were good, I would cut them for flooring. All I really had to do was sort the lumber into two piles while I was working. But, it wasn’t that easy.
Some logs would have a side that was good for producing siding, but the next side was only good for flooring. When I flipped the log over to a new side, my width was determined by how much I cut off of the last side, and it was always random. So, no matter what I did, even if I was cutting for a specific product, I would get stuck with lots of random width boards.
As I mentioned, wasting lumber kills me, and every time I ripped random-width boards down to some set width, leaving wide scraps on the floor, I thought about how to stop wasting so much wood – then it clicked. Many years ago, a friend of mine showed me a floor he made for his own house out of random width boards. As far as I know, he only did it because he thought it would look different and make his house have a special touch that would only come from someone who made their own flooring. His floor was white oak with tons of character, in three different widths. It was beautiful, and it seemed to me that I could use these random widths in some form to stop wasting wood.
I don’t remember a specific moment when I had the epiphany (though I am sure I must have had one), but I figured out that using just three widths, 3″, 4″, and 5″ would cover every width of board I could produce and always leave me with less than 1″ of waste per board.
Think about it. 3″, 4″, and 5″ wide, rough lumber is covered right off of the bat since they are already useable widths. After that is a 6″ wide board, which will just be ripped into two 3″ wide strips. A 7″ board gets ripped to a 3″ and a 4″ strip, while an 8″ board turns into two 4″ strips or a 5″ and a 3″, whichever is preferred. Any width of rough lumber over 6″ wide can be broken down in some way with just the three target widths of 3″, 4″ and 5″. By the way, these are the rough cut widths. The finished tongue and groove flooring will end up with a face about 1/2″ less in width.
Random width flooring looks different, but not too different. At first glance, the viewer only notices the beautiful wood, and then after closer inspection notices the three widths, which lets them know subconsciously that the flooring is special. It stands out because it isn’t all one width like typical hardwood flooring, and most people have never seen or even thought of using random-width flooring. But, I say, “Don’t be scared of it.” It is different and not typical, but in a good way, especially when it comes to waste.
Believe it or not, until recently I had never done any turnings. I have been messing with wood for a solid twenty years and never once have I even turned on a lathe. I’ve seen Norm do it a bazillion times on “The New Yankee Workshop” and listened to plenty of other woodworkers tell me about their turning escapades, but I never felt inclined to do it myself. I guess it’s because I am not attracted to work that has turnings in it, so they rarely end up in pieces that I am building and if they do, I pay someone else to do them.
It wasn’t by my choosing, but I did agree to build a bench with multiple turnings after my customer changed her mind on what she wanted. She showed me a picture from Sawkille.com of their “Tall Rabbit” bench and asked if I could make one like it for her with a variation on the length. Since I already had her deposit on the previous project, I didn’t want to say no and send back the money, so I said yes. I looked at it this way, if I consider myself a real woodworker and I am interested in spreading real-world useable woodworking knowledge, then it can’t hurt for me to have more knowledge myself. After all, was it possible that I would consider myself a real woodworker and die one day never having done a single turning? Sounded pretty hypocritical to me.
First off, let me say that the work from the kids at Sawkille is very nice, and though I don’t know them from Adam, I do appreciate the attention to design details that show in their work. I spent a lot of time messing with small details and proportions, and there is no doubt in my mind that they have spent exponentially more time on those same details and slight variations than I did.
The picture above is in black, but my customer saw some other variations and decided to go with bleached maple, and though it didn’t seem necessary on maple, bleaching gave the wood a very different look. The maple went from a light yellow-white to bone white with a couple of applications of two-part wood bleach. That part was as simple as could be – the actual turning was not.
Actually, I take that back. The short turnings weren’t too bad. After I turned the first couple and started to get a feel for it, the next 17 went pretty fast and came out nice. I got my time down to about 15 minutes each, which didn’t set any speed records, but it was a pace I could live with. If I did them all at that rate, I could turn all of the pieces in about 6 or 7 hours, which sounded like a fine day of work.
As you might have imagined, I wouldn’t have much to talk about if it all went down like that.
My troubles started when I stepped up to the legs and long stretchers. All of those are in the 24″ range, and about three times as long as the easy-peasy pieces. Out near the ends, where everything is solid, the work went according to plan, but in the middle, I would simply say that it did NOT. No matter how I attacked the middle, whether it be with a light touch or a hard push or maybe a quick jab or a different angle or a different speed or perhaps standing on a different foot or even just squinting a bit more, nothing improved. The piece of maple just jumped and kicked like a bucking bull, and I couldn’t stop it.
Even though I knew my problems were the result of the longer pieces, I imagined that a better turner (or at least someone who had turned at least once before in their life) could overcome the bounciness with better technique. I kept trying different lathe tools and worked slowly to get the pieces as good as possible, and while the overall shape was acceptable, the surface was not. It was nubby, like off-road truck tires, and there were plenty of spots were the wood was just ripped instead of cut. To finish up, I finally dumped the lathe tools and grabbed the sandpaper. I decided to take full advantage of the easy sanding on the lathe and let the paper do the work. Of course, it took awhile, but it was the only way I could come up with to overcome the bouncing spindle syndrome.
After I had a few of the long turnings done, I talked/complained to random shop patrons about my lathe fun and one of them mentioned using a rasp. Apparently, he had more turning knowledge than me (I think everyone does), and he had used the rasp a lot. It made good sense – a rasp is really just super-aggressive sandpaper. Plus, by holding the rasp more parallel to the piece than perpendicular, the rigid flat shape worked great to form the gradual curves with no humps. It wouldn’t have worked so well on intricate turnings, but it worked great in this case.
After finishing this project, I have a new respect for wood turners and turning. After all, my turnings were simple and still provided quite the challenge. When I think about some of the turnings I have seen, especially in other works, like large hollow vessels, and I consider all of the issues that the turner might face in a project like that, it really makes me appreciate the craft of it. And, though I may never do another turned project in my life, I am glad I gave this one a go.
For Christmas, I decided my daughter needed a bunch of dominos (not to play the game dominos, but to stand up and knock over). I always liked playing with dominos, but was always disappointed when I ran out, so I then decided it should be a big bunch of dominos. After doing a little on-line research, I quickly concluded that a purchase of a big bunch of dominos, even the cheap ones, was going to add up, and since I have a never-ending supply of domino stock in my shop, I set out to make them.
First things first, I needed to figure out the dimensions, and this ended up being the most difficult part of the entire job. I tried searching online, assuming there would be a standard size and I would just copy that, but I didn’t find anything standard. The sizes seemed to be all over the place. Then I thought, “OK, maybe there isn’t a standard size, but there must be some sort of standard ratio or proportions to a domino.” But, as far as I can tell there isn’t, or at least there isn’t anything clearly published that is quick and easy to find. There was nothing with the heading “Standard Domino Sizes,” like I was hoping to find.
Here’s the good news, after scouring the internet for information and making a few hundred myself, I have finally figured out the perfect proportions for what I am calling a standard domino. Now, it seems quite simple and very obvious, but it took me awhile to put it all together (we had to knock over a lot dominos for it to click). The dimension that took some time to nail down was the thickness.
At first, I just guessed at it and made the dominos a thickness that looked in proportion to the length and width. After using the dominos though, it seemed like they were a bit too thick. They look fine and don’t feel unlike a domino, but they don’t fall over very well. They still fall, but they are just a bit too stable and don’t fall with much force. They aren’t bad enough to throw away, but they could be better.
After playing with the dominos more and making structures with them, similar to building blocks, it all came into focus, and I found the magic ratio. When we stacked the dominos in different orientations, things weren’t lining up and the thickness was to blame. We would stack some dominos on their side, some standing, and some laying down, and the ones laying down didn’t quite line up with the ones on their side. It was close, but not that close. Three dominos laying down were just a bit taller than just one on its side, which made them impossible to use as stable building structure. If they were just a bit thinner, everything would line up when they were stacked and they would topple just right.
So, here is the magic ratio, expressed in a three different ways:
Thickness = X, Width = 3X, Length = 6X
Width = X, Length = 2X, Thickness = X/3
or in actual (standard?) size
Length = 2″, Width = 1″, Thickness = .33″
Of course, if you are going to make your own dominos, they don’t have to be 1″ wide. They could be any dimension you want, but be sure to follow the above ratios for them to really work well.
One of the first things I needed to figure out when I started cutting rough lumber on a sawmill was what thickness to make it. I could generally determine if I wanted it to be thick or thin, but just how thick or thin? 4/4 lumber is 1″ thick, so it should be rough cut at 1″ thick, right? Not exactly. For hardwoods, the commercial target for 4/4 lumber is actually 1-1/8″, which allows enough margin to produce dried and planed lumber at a thickness of 13/16″ or 3/4″ (3/4″ is acceptable, but the extra 1/16″ of thickness in 13/16″ material allows room for additional planing or sanding after panels or doors are glued up).
The crazy thing is that back then I couldn’t find solid information on lumber thicknesses anywhere and when I referred to the NHLA (National Hardwood Lumber Association) guide, the thicknesses didn’t match up with what I was finding from hardwood producers. The NHLA guide doesn’t include the bonus 1/8″ of thickness – 4/4 lumber, for example, is specified at a minimum of 1″.
In my experience, 4/4 hardwood lumber cut at 1″ is too thin to consistently produce flattened and planed lumber at 13/16″ thick and will even have trouble producing 3/4″ thick unless the boards are very flat. The only way 1″ thick rough-cut hardwood lumber can plane out completely to 13/16″ or 3/4″ thick is to skip the flattening and just plane the lumber. This will produce thicker finished lumber, but it won’t be flat and straight since the planer will simply follow the curves of any crooked boards. From a woodworkers perspective this is a horrible practice and makes woodworking much more difficult. For this reason, I cut my 4/4 hardwood lumber like all other quality producers at 1-1/8″ thick and don’t accept anything from other sawmills or wholesalers at 1″ thick.
Starting with the lumber measurement and adding 1/8″ for the final thickness is how all of the hardwood measurements go, with a target for 4/4 lumber at 1-1/8″, 5/4 lumber at 1-3/8″, 6/4 at 1-5/8″ and 8/4 at 2-1/8″. These are the commercially accepted numbers, and except for 8/4 lumber the ones that I shoot for. The problem with 8/4 lumber is that since there is more wood it shrinks more than thinner lumber and 2-1/8″ thick just isn’t enough thickness to flatten and plane lumber to consistently finish at 1-3/4″, which is the target for 8/4 lumber. When I flatten and plane batches of 8/4 lumber milled at 2-1/8″ thick it isn’t uncommon for half of the lumber to finish at 1-5/8″ thick instead of 1-3/4″.
Because I think 2-1/8″ is a little thin, I commonly cut 8/4 lumber at 2-3/8″ thick. 2-3/8″ thick is twice that of 4/4 lumber, plus the 1/8″ saw kerf that would have been between the two imaginary cuts. The extra thickness not only impresses the ladies, but it assures a final dried and planed thickness of at least 1-3/4″ and officially uses no extra wood when compared to cutting 4/4 lumber (to keep things simple, a friend of mine simply calls it “double four quarter” lumber). As I mentioned though, 8/4 is commercially sawn at 2-1/8″ thick, so if you cut it at that measurement it isn’t wrong, 2-3/8″ is just better for the end user (none of my customers have ever been upset that the wood is a little thicker).
The previous examples were for hardwoods, but softwoods, like white pine, can be cut thinner since they shrink less and dry straighter overall, plus softwoods are commonly used for construction purposes instead of furniture, which don’t need the extra thickness for secondary planing or sanding, so 3/4″ final thickness is common for 4/4 softwood lumber. For 4/4 white pine for example, I cut 1″ thick, which will finish at 3/4″. And, for cedar, which shrinks very little and is very straight and stable, I will go even thinner, down to 7/8″. In general though, softwoods are cut on the standard quarter scale with 4/4 lumber measuring 1″.
The scale below shows the target hardwood lumber thicknesses for commercially produced, rough-cut lumber and their planed thickness counterparts. These are the sizes you should expect to find when shopping for hardwoods.
Hardwood Lumber Measurements
Quarter-scale measurement Rough cut thickness Planed thickness
4/4 1-1/8″ 13/16″
5/4 1-3/8″ 1-1/16″
6/4 1-5/8″ 1-1/4″
8/4 2-1/8″ (or 2-3/8″*) 1-3/4″
*2-3/8″ is a better thickness to consistently finish at 1-3/4″ thick, but 2-1/8″ is the norm.