The Back Splats
Note: When I talk about the many parts of this chair, I name them as if I were sitting in the chair.
Just to let you know where this class will be heading. I won’t be going into “great” detail on how to set up this tool or that tool. I also won’t be going too deep into the creation of each and every part. If I did…I’d be taking way too much of your precious time. Look at this class as a “tips and tricks that will hopefully make your chair building just a bit easier and fun” class.
Before you start any project in your wood shop, it’s very helpful to have a “shop foreman” nearby. Why, you ask? Because if you happen to do something drastically wrong with a particular cut, you’ll know about it right away by the look on her face.
As mentioned in the previous “Intro” chapter, I made one chair from start to finish. My wife and I decided to have 10 chairs total, so from this point forward…I’ll be making the remaining 9 chairs.
With that said, let’s dive in…
The order in which you create the many parts of this chair isn’t all that important, however I have laid out the chapters in what I think “might” be the best sequence. Use your own judgement.
So now that you’ve decided to tackle this side chair project, let’s jump right into making some of the more fun, yet challenging parts. The back splats. The back splats are the parts that touch your entire back as you’re sitting in the chair.
The 7 back splat parts are glued up in a “curved” fashion to better fit your back.
There are two different parts to the back splats. I’ll call them the “thickies (4)” and the “thinnies (3)” from this point forward.
The thickies: (Or larger more intricate part of the two parts.)
After locating the nicest cherry in my pile of lumber, I planed the thickies down to their near final thickness, and then cut them a bit long and a bit wide for now. Why? I’m fortunate enough to have a surface sander in my shop, so I always leave parts a bit on the “large” side. The surface sander is a great tool for bringing parts down to their final dimensions.
Once I had 11 or 12 chunks roughed out for the 9 remaining chairs (it never hurts to have a few spares), I then cut the thickies to final length. A quick trip to my table saw set up with my stacked dado blade and sacrificial fence…and the tenons on each end of the thickies were all cut to their final thickness. This is also a good time to hit the blank with an orbital sander to take out any imperfections. (See photo below.)
One fairly important thing to keep in mind while making your back splats. Label each part so that when you go to put them back together they’ll all end up in the correct orientation. This assures you that their grain direction will look somewhat normal and not mish-mashed.
It’s not important “how” you label your back splat parts. Just make sure you’re comfortable with your labeling system. Seeing that I was making 9 more chairs, I had the need to keep things organized.
Some woodworkers draw a triangle across the face of all parts in hopes of matching them up later. With 11 or 12 piles of thickies, that just wasn’t going to fly. So I chose a much more reliable labeling system. (See photo below.)
Next you’ll want to rip each of your thickie blanks into 4 strips according to plans. Cherry tends to burn easily, so a couple gentle passes through the surface sander not only takes those burn marks away, but it also brings my thickies down to their final width. (See photos below.)
Now that the thickies are down to their final width, it’s time to plow out the “stopped” grooves on both sides of the two middle thickies and just the inside edges of both outside thickies. Confused yet? You’ll be making 6 grooves for each full set of back splats. The following photo should clarify things. (Note shop foreman in the background still inspecting my work.)
In the next set of photos you’ll see how I plowed out the “stopped” grooves to make room for the thinnies. You’ll also see how I used two different types of push sticks to safely rout the thickies…a homemade plywood push stick and the Gripper. Both methods worked exceptionally well. Remember, don’t plow out the two very outside edges of the two outside thickies!!
The photo below shows the “stopping device” at the end of my router table fence. Once the thickie was routed to that stopping point, I’d shut the router off with my foot pedal switch, wait for the bit to come to a complete stop, and then gently remove the routed thickie from my router table. (WARNING: You need both hands on deck for this process. NEVER let go without first stopping your router!!) Invest in a foot/floor switch. You’ll never regret it.
This is what your routed edges should look like once you’re done.
Could this process be done on the table saw with a stacked dado blade? As we Minnesnowtans say…you betcha.
It’s pretty obvious that we’re not quite done with the thickies yet. All of those rounded over grooves need to be squared up. I’m not very good with your typical chisel, so I chose to purchase the square 3/8 inch mortising chisel from Rockler shown in the photo above.
Once I learned just how hard to hit this chisel with a hammer, things went very well. Drawing a pencil mark across the very tops of the squared off grooves really helps as well. Note in the photo below how I butted all of the thickies up against a clamp, and then finally drew my pencil mark in its proper spot with a straight edge.
(Don’t forget those three magic words. Consistency, consistency, consistency.)
The photos below show 2 groups of 4 of the nearly finalized thickies. The first photo is one side of the 8 thickies, and the second photo shows the opposite sides of the same 8 thickies.
The final step you’ll need to take to complete the thickies is to cut the little tenons on both ends down to their final width. I did this on my table saw with a stacked dado blade and my Incra miter gauge.
Note: The bottom tenon on each of your thickies is most likely already done for you seeing that the router bit plowed out that part of the lower tenon. (Except for the two outer edges of the two outer thickies where there are no grooves.)
Important note: This is another place where those 3 famous words come into play. Consistency, consistency, consistency. Make sure that you have your table saw, dado blades, and whatever “stop” system set up properly. To this day I’m still not too sure what happened on a few of my thickies. Those few were ruined due to my dado blade going beyond the base of the tenon and into the meat of the thickie. This is where I’m very thankful I made lots of extra thickies. More cherry scraps for my smoker. :)
Next stage of the back splats, the thinnies: (The shorter, thinner back splat part.)
The thinnie is fairly simple to create. I built a very crude sled to take my thin cherry stock through my thickness planer safely. (See photos below.)
I like to keep these thin slabs a bit thick, and then finish sand them with either my orbital sander or my surface sander…constantly checking their fit on one of my thickies. (You may find this step easier to do after you rip the thinnies to their final width in the step below.)
Once the thinnie slabs are planed, you can then rip the thinnies to width. Next you’ll need to create a 2 degree bevel on both sides of all thinnies as mentioned in Kevin’s plans. (I did this on my jointer.)
This 2 degrees is what makes the entire back splat assembly curve around your back. Sand and dry fit all thinnies and thickies, and get ready to glue all 7 parts together.
To make the back splat subassembly process an easy task, use an upper and lower crest rail to hold the parts in their proper orientation while the glue dries. See photo below.
(No glue on the tenons at this point…just on the edges of the thickies and thinnies. Keep the glue to a minimum. Glue squeeze out is NOT something you want to deal with on these parts.)
So you’re probably asking yourself, “Which comes first…the back splat subassembly or the upper and lower crest rails?” Great question.
Here’s what I did. I created one set of upper and lower crest rails along with their mortises first. (See next chapter.) Then I used that one set of crest rails to help glue up just one set of back splat subassemblies. This single glued up back splat subassembly came in handy while making a permanent template for laying out the 4 mortises in all future upper and lower crest rails. I know…it doesn’t make much sense…but it worked for me.
By using that 3/8 inch mortising chisel from Rockler mentioned above, I had to resort to making some of my crest rail mortises a bit larger than normal to accept a couple of “out of line” back splat subassembly tenons.
You may run into the same problem I had with a couple of the back splat tenons just not lining up properly with the crest rail mortises. Don’t worry about making your mortises a bit larger than normal…the thickies are large enough to cover those extra large mortises. Remember, this is not a structural glue up joint.
When the back splat assemblies are all glued up and dried, I like to hit them with some 180 and then 320 or 400 grit sandpaper just to clean them up. Don’t push too hard though…remember there’s not much glue in those joints. (See final photo below.)
See you at the next chapter…
Dale “Gramps” Peterson.
-- If at first you don't succeed...DO NOT try skydiving.