Drop Leaf Table in Alder
Previously I wrote about a small drop leaf table that I was trying to prototype and refine. I have finally finished what I think is the table I am happy with. It is roughly 36″ square when fully extended and roughly 12″ x 36″ when fully closed.
This table was really quite enjoyable to build and I think I will make more of these in order to fully perfect this form. The main differences between this one and the prototype I made earlier was using hand made rule joints on the leaves, doing away with the through mortises on the legs, and of course using Alder instead of salvage Hemlock. So in this article I wanted to be a bit more specific in showing the process of building this table, I took a lot of pictures so hopefully that will help if you ever get the urge to make a nice little table like this.
Building the table
The first challenge I faced was getting a harmonious set of boards for the top of the table. I had acquired a nice bunch of Alder but the pieces were not all that harmonious when I actually started laying them out for the project. I had some very attractive darker pieces with almost a quilted grain pattern, but not enough for the entire project. So I had to get clever. It is not easy to see in the picture at the right but I used the darkest and most flamboyant piece in the center of the table and then blended it to some lighter less figured wood toward the the edges. This seemed to my eye at least to be the most attractive arrangement, particularly when you realize that most of this tables life will be spent with the leaves down, so the center leaf will really be the focus of attention for anyone looking at the table in use.
The 8/4″ stock for the legs was also dark and somewhat figured so I had to save some of the dark figured wood for the rails as well or the whole project would have taken on a terrible Harlequin look. The remaining lighter wood I used for the unseen parts of the carcase. As you can see from the picture at the left there was a very significant difference in color and figure in this stack of Alder. It was however, very agreeable wood to work with. This was my first time working with Alder and I really loved it’s working properties. It cuts and planes wonderfully, even the highly figured pieces were nowhere near as ornery as Maple figured like this would have been. I was able to bring this entire project to a finish ready state with nothing but edge tools, in fact most of it was beautiful right off the plane. There were only a couple of small areas that were so woolly that I was not able to smooth it to my satisfaction with a normal plane so I had to use a cabinet scraper.
Once I had the basic layout of the pieces figured out I was ready to begin work. I started with the legs. In my prototype I used an octagonal taper for the legs, but for this one I wanted simpler lines so I opted for a more conventional two sided taper that gave the legs some grace and also gave the appearance of a slight splaying of the legs which I find absolutely necessary on a narrow table like this.
The first step was to mark out the various orientation of the legs and to number each of them. I learned on the prototype that it is exceptionally easy to confuse the orientation of parts during the construction of this table and this can quickly lead to disaster.
The next thing is to cut the tapers. I did this with nothing but planes and although it could be argued that a jig in my table saw would be faster, I think that is only true if you need to make a lot of these things. Because when you are done with the table saw you would have to tune each one up with a hand plane to get a decent finish on them anyway.
After you have marked out the taper on each leg you are ready to begin cutting the tapers. I used three planes for this. I started with a jack plane set for a fairly course cut, next a try plane set to a fine cut, and finally a smoother for the final finish.
To get started you begin on the narrow end of the taper taking short strokes until you have a short section of the taper running parallel to your guidelines. Once you have a good straight start you simply keep planing, your stoke will get longer with each pass. As you do this watch the leading edge of your cut. It should run as close to perfectly perpendicular as possible. This will assure that you are working straight down to your guideline on both sides without constant checking.
When you are finished you should get the following effect when you stack them together with the correct orientation. As you can see the legs give a nice splayed look even though they are in reality still just as straight as they were when I cut them. It was at this point I decided that I was not going to add the extra facets to make them octagonal. They looked nice the way they were. So I moved on.
The next thing I did was edge joint the top to prepare it for glue-up. Make sure that you do no more than you can easily handle because you want your joints to be glued up as perfectly as possible. If this means three separate glue-ups to get the entire table top together that is far better than trying to correct for a shifted joint later.
I glued up in three sections then the whole slab into one piece. I then made my final measurements and cut it into three pieces later on my table saw. I tried to build this entire table with hand tools but partitioning the top and ripping the legs from 8/4″ stock and cutting the 1/4″ cross-cut dado’s for the carcase were all jobs I ended up breaking down and using the table saw for. The hand tool equivalent for these tasks were either too hard or too risky for me. Sorry purists. Maybe next time.
Mortising the legs was another process that I changed after building the prototype. In the prototype I used through mortises and I chopped them with a chisel. However for this version of the table I wanted a cleaner look so I used stopped mortises that meet inside of the the leg. Then I used mitered tenons to bring the whole thing together. I find that stopped mortises are far easier to do to a clean consistent depth if you drill to depth first then follow up with a chisel. You can see in the next image what I was left with after I was done on the drill press.
It is a simple process then to clean out the motices to the proper depth. Be careful though, although you can get away with a lot cosmetically with this design, you do not want your mortises to get too loose and they must be absolutely square. Even a tiny amount of drift from square will be multiplied about 7 times by the length of the leg. Even a 1/32″ becomes very visible under these conditions. Think of the legs as built-in giant winding sticks and you get the idea.
Next up is fitting the tenons to the mortises. But before you try that you need to cut the side rails at the point that you want them to hinge on the knuckle joint. REMEMBER that your side rails need to be long enough to allow for the depth of your tenons AND remember that cutting the knuckle joint will shorten your rails by the the depth of your knuckle joint pins.
Once your rail pieces are cut to length you are ready to mark and cut your tenon shoulders. There is nothing complicated here, you just cut down to your lines. The next question is, do you saw your tenons or chisel them. This depends entirely on your material. I tried to chisel first but I found after the first one the the grain was just to hairy to do this consistently so I switched to the saw after the first one. I then cleaned them up with chisels and a rebate plane that I use in place of a shoulder plane (it actually works just fine and cost 10$ at a flea market it’s just not as cool as a shoulder plane). Next I need to fit the tenon to the mortise, so I had to fit the height to the height of the mortise.
This is simple just “show” the tenon to the mortise and transfer the exact height and placement to the tenon and cut the corners out with your dovetail saw. Don’t worry about cross-cut saws or rip saws here, people just say this stuff to sell saws. A 15 tooth dovetail or tenon saw filed rip will crosscut all day long just fine, just be sure to cut your lines to ensure that you get clean edges on your cut. Also make sure your saw is sharp, a dull saw will make a mess no matter how it is filed.
The last thing I do is to cut a small chamfer on the leading edges of the tenon this makes fitting and gluing much easier later. Then it is just a matter a careful paring and fitting of the tenons. One caution here, do not allow yourself to favor one side or the other as you pare and trim. It is possible to create a tenon that fits well but is no longer perfectly square and true with the face of the rail. This is another place where the length of the leg will serve as a 7x magnifier of your errors. This is easier to do than it sounds, so you have been warned.
Making the knuckle joint starts out very similar to the process for making a dovetail joint. Make sure that you have an odd number of fingers on your joint. No less than 5 for obvious reasons.The other peculiar thing is that you want to mark your baseline to twice the depth on the inside of the joint on the side with the most fingers (in my case the side with three fingers. Because the 2 sockets on this half of the joint need to be relieved to a 45 degree angle to allow for free movement of the hinge.
The two pictures at the right should make it pretty clear how straight forward this is. Once you have the 45 degree cuts let in it is a simple task to remove the waste with a sharp chisel. The mating piece is cut square like a box joint. When you have both pieces cut test fit them, they should fit very tight. It would be a big mistake to build a joint like this with a loose fit. You have a lot of leverage when you use this joint so you do not have to worry it will work just fine even if it is very tight. And it will only get looser with time. Just don’t force it and split your joint open.
The real trick comes next. It is absolutely essential that this joint be drilled perfectly plumb on both axis. If it is off either way it will either be crooked when it is closed or crooked when it is open. No matter how much of a hand tools freak you are, you should use a drill press for this and drill from both sides and measure very carefully. And you still might have trouble. In my prototype I messed this up and drifted ever so little on one of my joints. This tiny error was very visible when the leg was extended. Once again the length of the leg magnifies the tiniest error. In fact as simple as this table is in principle in reality it can be a bit of a challenge to build because the carcase has to be perfect or the legs will not look straight. There are several steps where even a small error can really have a big effect. Once the holes are drilled then I just used a stainless steel pin (the store was out of brass in the size I wanted) and drove it in over the anvil on my vise. This mushroomed each end just slightly, which is all it takes to keep the pins from falling out. Now it is time to shift the focus to assembling the carcase.
I start by building nice square sub-assemblies I glue the rails to the legs making sure they are absolutely square. Then I begin cutting the inner carcase. This is another task that I used my table saw for. Mostly because I did not have any hand tools that could cut a 1/4″ crosscut dado that close to the end of a board. So I used a stack dado set for this task. Again the only trick here is to make sure that everything is square and straight. Clamp it up on something that you know is flat. And practice before you start to use glue.
If you are careful this is the most enjoyable part of the process because now it all starts to come together. Once this is done all that is left is fitting the top and applying the finish. And if you have been careful up to this point to smooth each piece before assembly the finishing process goes much faster as well. Since I have not provided any measurements for this table there is one design element to bare in mind. The swinging leg needs to clear whatever hardware you are using and the hinge needs to be placed so that it supports the leaf but does not obviously extend beyond the leaf. In the case of this table that was around 3′ long by 1′ wide folded with 12″ leaves I needed the leg to swing in an arch with about an 11″ radius. And I had an overhang of about 3″ on each end.
Next up is the rule joint for the top. I am assuming that the top is cut to size and the edges are jointed. This is the step I think I spent the most time obsessing about and in the end I think it was the most fun of anything I did on this table. My first thought was to use a router with matching cove and bead bits. But although I had two of these sets one was too big and the other far too small. So I went to town wasted 2 hours and found nothing helpful so I came home and made a hand plane for the job (I wrote about that project here). Making a rule joint by hand seemed a bit frightening at first, but once I did it I found myself thinking, “what was all the fuss about?”.
The first step is to mark the profile you are going for on each end of the material. Then with a cutting gauge follow that profile all the way down the length of the leaf. Honestly you just plane down to these marks. But I did experiment a bit first and I do have some advice if you have never done this. Use a fence. This made all the difference. For the cove I planed a bevel with a block plane down to the point where I was near the longitudinal marks but not all the way to them.
Then I clamped a straight piece of wood to guide the molding plane for the first few strokes until I had a nice groove cut in the middle of what will be the cove. Then I moved the fence back but I did not remove it because it protected me from slipping out of the cut and scaring the table top (or bottom). Once you get going you just plane until you hit all your marks. When it looks right it is right.
The bead portion of the joint is actually even easier than that. I used the same plane to do the whole thing. My old 10 buck metal rebate plane. It works so well I use it for both rebating and as a shoulder plane. I am not saying I would not like a nice LN shoulder plane but this works.
I started out by clamping my fence to the center leaf and just cutting a rebate down to the top of the curved profile. Then I just rounded over the bead by eye leaving the fence in place to protect the pristine edge on the top. This not only worked on the first try it left barely perceptible facets in the bead which looks clean but hand made. I liked it so much I did not even sand it when I was done.
I did do just a bit of final fitting by taking a pass or two here or there and I also relieved the under side of the bead to allow just a bit of clearance when the leaf is folded down. How much depends on a lot of factors. The key variable is the exact position of the hinge pivot when your hinges are mounted. What I did was to locate this position as perfectly as I could then I took my compass and traced the arch of the bead and looked at how much I needed to clip off the bottom edge to allow the cove to rotate without rubbing.
In my case I needed a very small amount of rounding on the bottom edge which is a good thing since it prevents any possibility of the edge catching when you put down the leaf and doing something nasty. As you can see at the left the rounding at the bottom of the bead is barely visible.
I used hardware store hinges for this which I felt bad about but real deal rule joint hinges are so expensive that it would have nearly doubled the cost of this project. It seemed a high price to pay for something nobody would ever see. And the hinges I did choose were very strong so I was not worried about the functional quality of the hinge. It just looks a bit sad when you tip it upside down and see those 5$ a pair hinges. Maybe next time. Cutting in the barrel of the hinge is also easy I just mortised them in with a 1/4″ chisel. Be careful though you do not want to get careless and cut in so deep you break through the bead. In my case there was not a lot of wood left between the barrel mortice and the bead. This is a case where hand tools are beyond all doubt better than power tools.
Unless you plan on going in production on this sort of thing cutting these rule joints by hand was quieter, safer, and easier to adjust and perfect than trying to set all this up for power tools. I did all of this in a couple of hours of actual work.
The top is held on with a couple of screws into the center leaf and then it is ready for final finishing. I cut a wide but shallow chamfer around the perimeter of the bottom of the tabletop to “lighten” the look of the top. I also put a small conventional chamfer around the perimeter of the top just to finish it off. Some might prefer to route the edges of the table but I was going for a very simple look to this table. The wood has a sort of quilted grain pattern that give the piece a lot of visual interest so I wanted the rest to be fairly understated.
As for the finish I used about 4 coats of a home blended oil finish. One part Boiled linseed oil, two parts turpentine, and two part spar varnish. I call this 221 and I really like it. It produces no surface build but soaks in deeply and is very tough for an oil finish. The prototype table has nothing but three coats of this on it and the people that are using it, take no special precautions when placing drinks on it. They use it like any other table and have had no trouble. I have written a full post on this here, it is a finish I have used in one form or another for many years and I really love it.