I own a 6 inch jointer. I will pause for a moment while all of you that own 8+ inch jointers laugh and mock me.
OK, now that we have that out of the way, let’s continue. Because of my jointer’s limited capacity, jointing boards that are wider than 6 inches can be a problem. Now, some people solve this problem by ripping the boards down to less than 6 inches, jointing them, and gluing them back together. This method works, but I have two fundamental issues with it:
- This sounds like a lot of work, and I am a very lazy.
- It’s just a crime to rip down a beautiful board to meet the limitations of your power tools.
My jointer may be limited to 6″ wide boards, but my lunchbox planer can handle boards up to 13″ wide. Putting your 13″ planer to work flattening boards is easier than you think… all you need is a simple jig called a planer sled.
If you listened to episode 21, you know about my preference for jigs that are built with scrap laying around the shop in 15 minutes or less. Why? See #1 above. I’m proud to inform you that my planer sled meets both of these criteria. Here’s a picture:
Pretty simple, huh? It is essentially a scrap piece of melamine with a fence made from scrap cherry screwed to the end. When constructing your sled, there are two things you need to watch out for. First, make sure that the base of your sled is flat. Notice there are no gaps when my sled is lying on a flat reference surface (my table saw):
And second, make sure that the screws you use to attach the fence to the sled are countersunk below the surface. If they aren’t, you run the risk of damaging your planer knives if you accidentally nick them. You could glue the fence down instead, but I like to have the option of replacing it with little effort.
So how do you use it? Let’s walk through the process of flattening a board. Here is the rough-sawn plank I am starting out with. It’s a 4/4 cherry board about 8″ wide and approximately 8′ long.
I always start by cutting my furniture parts down to rough length. It is much easier to work with these shorter boards than it is to muscle an 8′ long plank around the shop.
Laying one of the boards on my reference surface, you can see how out-of-flat it is.
Before putting this board on the sled and running it through the planer, you need to ensure that it will be absolutely stable. Push down on each corner of the board and observe the result. If the board moves up and down, then you need to shim it. I use thin offcuts from my table saw that are usually laying in a pile on the floor.
At this point, the board is absolutely stable. I can push down on any part of the board and it will not move. I bend the shims upward to break off the excess (wear your safety glasses) and secure them to the board. So how do you secure the shims to the board? You could use hot glue or some other fancy-schmancy method, but in my shop, I use good old blue painter’s tape.
Once the shims are secured, flip the board back over and double check that it is still stable on your reference surface. If everything looks good, it’s time to put that planer sled to work. Put the board on the sled with the leading edge pushed up against the fence. Needless to say, make sure the tape side is down.
At this point, you’re ready to go. The flat bed of the sled acts as the reference surface for the planer knives when you run the board through the machine. The knives cut a surface on the top of the board that is parallel to the flat bed of the planer sled. The planer’s rollers pull the board tight against the sled’s fence, which ensures that the sled moves smoothly through the machine along with the board. Here’s a picture of the board after it’s first pass through the planer. The board was cupped, and you can see how the knives flattened the high spot down the center.
Keep running the board and sled through the planer. Once the top side of the board is flat, you can take it off the sled, remove the shims and flip it over. Now, use the flattened side of the board as the reference surface and run it through the planer to flatten the other side of the board. Here’s the board after I’m done machining it flat and to it’s rough thickness.
I still prefer using my jointer to flatten one side of a board whenever possible, but when I end up with a board that is too wide, this method works well for me. And it sure is nice to preserve the grain patterns of the wood. Ripping the board in half and gluing it back up will never look this nice.