How to Flatten a Live Edge Wood Slab.

So for those of you that follow me on Instagram, you know that about two years ago, a friend of mine called me and said, I have a 100 year old walnut tree on my property that needs to come out. Do you want it? And at first I said, I don't know what to do with a 100 year old walnut tree, but he said, I have a bandsaw mill and a place to store it. So we milled up about 85 walnut slabs, which actually are on my website. I'll link those down below. But today we're starting a desk for a friend of mine and we need to flatten it. And I want to show you how I go about flattening a slab. So let's get started by building our mechanism and our sled. And then we'll go about flattening this and I'll tell you how I do that. Okay, the first thing we're going to do is build the sled that will hold the router. Now you don't want a lot of slop in this, but you obviously don't want to screw yourself and make it so small that the router is going to get stuck in places. But what I'd like to do is I just take, I put a bit with a point on it in my router, and then I'll just bring it up to just about below the surface of the router. And then I'll use two of the screws and the tip of that router bit to make sure I'm in my widest spot. My router is about seven inches. So I'm going to make this about a seventh and an eighth wide. However, you need to add the thickness of your material. Now I chose melamine for what is going to hold my router because one, it's got a slick surface, so it'll be easy to pass back and forth. Two, I know that it has a straight edge when I buy it. So that way I can run that against my fence and make sure that I get straight cuts. The important thing to know is to add double the thickness of your material to your width, because you're going to want to make sure you put the rails on top of it because you're going to glue and screw it, and that's going to add extra rigidity to your sled. If you put them on the side, you're going to have a lot more chance of bowing. So you want to make sure they're on top, and that way it supports your router better. So let's cut this up, and I'm going to show you how I put that together. Okay, we've got everything put together. The sled is looking good. We got the stops on either end, so this way it won't slide off the rails. And now we need to cut out the middle for our bit. You could probably just put the bit in your router and slowly bring it down, but why waste the sharpness of a bit on MDF? So what I'm going to do is I'm going to take a Forstner bit. I'm going to draw it right there. I'm going to cut out the lines going down both ways with a homemade track saw. I have a great video on that, which I'll link right here in the corner. But you could run this along your table saw and just raise the blade. There's probably a hundred different ways to cut this out. All right, we've got our sled done, and man, is this thing rigid. It really just came out great. Obviously, glue's not going to work that well on melamine, so that's why we put nails and screws in it as well. I put stops on the end, so that way this can't slide off the rails once we make them. And now, here is the most important part of this. You need to think about a planer. A planer references, that's essentially what we're creating when you do a slab flattening jig. Sorry, that's really hard to say. You need a good, solid reference area. So now, it is time to make sure that our table is straight and parallel. And now, there's a lot of ways to do this. You just need a long, straight edge, and you just need to check it on the sides, in the middle, on the ends, in the middle, and then do diagonal. And the best way to do that, I believe, is to add something to your tabletop, unless you have a tabletop that is easily shimmable, I guess you would say. So I have this table, my assembly table, the top comes off. So what I did was I took 3 1⁄4 inch ply, just little strips of it, and put it around all over. That would give me shim locations. And then I took a straight edge, and I looked for gaps underneath it. So I'd put it and see the two points of contact, and check for gaps, and then I would shim it up accordingly there. And once the table is flat, it's really easy, because then you can measure your rails off of your table surface. And so what I'll do is I'll take a combination square and set it to about 2 1⁄2 inches, because my slab is about two inches thick. It does have a little twist in it, so you want to make sure that you can fit underneath that. And then I'll take it and make sure that I pull my rails up off of my table surface and nail them to the edge. So once you have your table flat, you don't want to worry about where they are based on the stretchers of your table. You want to worry about where it is based on the height of your table surface. It doesn't need to be level like a bubble level. You know, it could be at 45 degrees as long as it's flat. You just want to make sure that that table is flat. So I'm going to go ahead and shim this up, pull on my rails, and then we're going to put shims under our slab and put it down with hot glue, just ensuring that our slab remains stationary while we're working. You don't really have to worry about leveling the slab on the first side. You just kind of want to split the difference between the twists so that you're not taking a ton off one corner and none off the other. So you just want to kind of get it roughly parallel. Not a big deal. Once you flip it over, that's when we're going to make sure that it's stationary and not moving and that everything's flat. So let's get everything flattened out and let's start flattening some slabs. Okay, we've got everything level, flat, secured, and ready to go. I've got this awesome slab flattening bit that I got from bitsbits.com, which is my favorite place to get router bits. I just found them a couple months ago and they're really, really great. Great customer service, fast shipping, and they have this special coating that they put on bits that make them last a lot longer. So they're really great. I'll link them down below. We're going to go ahead and start by just taking shallow passes. We don't want to go too crazy. Otherwise you don't want to risk your router jumping around or anything like that. So we're going to take like eighth inch passes overlapping by 50% until we get a completely flat side. Then we're going to flip it over. We'll remove all the shims, make sure the table has nothing on it, and then we'll register from the table. So let's get flattening. Okay, so we ran into a little issue here because of the twist in the board, I had to take off a little bit more than expected. And so that's okay. But now my router sled is too tall. I would have to stick the router bit way too far out of the router and that would be unsafe. And you don't want to do that. I think the maximum stick out for a half inch router bit is one inch into the collet. So we don't want to mess anything up. We have everything perfectly flat. The table's leveled, the rails are leveled. So our best option is to put something that we know is flat underneath the slab. So plywood, obviously. So I'm going to put a piece of plywood under here and that's going to raise it up three quarters of an inch and we're going to be good to go. Easy solution and keeps everything safe. All right, we've got this thing flat on two sides. It got a slight, slight, slight cup overnight, but it's really nothing to worry about. It's like a 16th of an inch over the whole length of the slab. So really not a big deal. So now what we're going to do is take the routing lines out of it by sanding it. I'm going to use 60 grit to start or 80 grit and the pencil trick. So that just means I'm going to draw pencil over the whole thing and sand until those lines are gone. Do that across the entire surface and then do it again with a higher grit. And that way I know I'm removing equal amounts of material from every single part of this, which is a great thing to do when you, especially when you have a piece this big, because otherwise you end up getting certain areas with more sanding rather than others. I haven't taken off all the bark yet. I'm only going to sand to 120 right now because I still need to do some work. I need to put in a wireless charging port on this. I need to engrave it and do a couple other things. So I'm just going to sand to 120 now. We'll do all that work. And then when we're at the end, we'll finish it up and sand it all the way up to 220. Woo. How's my hair? So guys, that's how you flatten a slab. It was a lot of fun. It makes a huge mess. So if you're doing it inside, make sure it's a place you don't mind getting dust on everything and in everything. In fact, make sure you're wearing tight underwear because you will get sawdust everywhere. Thanks for watching, guys. This was a really fun thing. This is part of a bigger project I'm doing. I'm building a desk for a friend of mine named Prior Baird, who's a musician, and we're going to do a really cool desk with wireless charging and his logo in it. It's going to be really neat. So that video will be out in a few days. If you're watching this in the future, go ahead and click the card. I'll make sure to put it here so you can click that video, but this is going to be a fun build and I am looking forward to you guys following along. So thanks for watching. If you're new here, please subscribe and give this video a like and do all those other things YouTubers ask you to do. I'm not sure why. Stay safe in the shop. Have a wonderful day.