How to assemble an Adirondack wooden chair

How to assemble an Adirondack chair

Once we have finished making all the pieces of the Adirondack chair, it is time to assemble the chair. And although the plans to make this wooden chair show instructions on how to do the Adirondack chair assembly, apart from being in English, they do not go into much detail. And the truth is that the first time we assemble this garden chair, it can give us some headaches. So let’s see how to assemble an Adirondack chair step by step.

Assembling the Adirondack chair

Although if you want to see all the details, don’t miss the video.

Read here all the articles on how to make an Adirondack Chair

How to assemble the structure of the Adirondack chair

Assembling the Adirondack chair sides

The first thing we are going to do is to assemble the sides of the chair. To do this, we start by using some clamps to attach a straight wood strip to the workbench. I put this strip on top of a couple of the plywood templates, because I want to keep it a little elevated.

Then, we measure 11.5cm from the front of one of the wooden sides of this chair, and place it against the straight wood strip as shown in the photo.

Measure the position in which to place the front leg

We put one of the front legs underneath, so that the side of the leg coincides with the 11.5cm mark I made on the side.

Screw on the front leg of the wooden chair

And I drill four pilot holes and I insert four screws.

Make sure that the side is mounted in this way to be able to drill first in the side and not in the leg. This way once the Adirondack chair is fully assembled, the screw heads will be hidden inside the chair.

Mount the left-hand side symmetrically.

And now I can assemble the other side of this Adirondack wooden chair. But notice that I mount it with the pieces facing the other way. Thus both sides will be symmetrical. They should not look the same, but symmetrical.

Screw the lower back support of the Adirondack chair backrest

Next is to assemble the lower support of this wooden chair. I just have to fit it into the notches on the sides and fasten it with a couple of screws. Then, I drive the first screw into each end, I make sure it is at 90 degrees to the sides of the chair, and I drive the second screw into each end of the support.

I always drill pilot holes before inserting the screws.

Stainless steel wood screws

I will use stainless steel screws to make all the joints. Specifically, I use 6cm long and 5cm long wood screws. All 3mm thick. The 6cm ones are adequate for the structure, which is made of 3cm thick wood. The 5cm screws are for the seat and backrest boards. Although I think these 5cm ones are a bit long. 4cm long screws would probably be sufficient.

How to adjust the back legs of the Adirondack chair

Now it is time to adjust the back supports of this Adirondack chair. To do this first I use clamps to attach a plywood strip to the top of the workbench. I place the front legs of the Adirondack chair against that strip, and I place the back supports as shown in the picture, clamping them with clamps to the sides of the chair.

Make sure that the back supports are also against the bar.

And pay particular attention to the position of the miter cut at the top of the back supports.

So, now it is a matter of centering the upper backrest support and screwing it in place.

And let’s notice that some wooden corners protrude from the inside of the curve of the upper back support. Then, I mark the shape of the protruding wooden corners, and I can cut them when I unscrew the upper support. I can unscrew it now, cut the corners and screw it back on. Or I can mount the back supports in place first, then unscrew the top support and cut the corners. This trick about cutting those wood corners is one of those little details that are not included in the assembly instructions shown in the plans for this Adirondack chair.

Aligning the Adirondack chair backrest supports

And I can now put the back supports of this wooden chair back in place. The trick is to position them so that they are perfectly vertical and with the curved edge of the upper and lower backrest supports perfectly aligned. To do so, we can use one of the backrest slats and a square.

Screw on the back supports of the Adirondack chair.

When I see that they are in place, I measure to make sure that both back supports are at the same distance from the lower back support, I clamp them with clamps, I make sure they are perfectly vertical, and I put four screws in each one.

Center and screw on the armrest front supports

This way I already have the front and back legs. And between the two will hold the large armrests that is so characteristic of these Adirondack garden chairs. But first I have to center the armrest supports in the outside of the front legs. And I fix them with a couple of screws.

Block for screwing the armrest of this garden chair

The next step would be to assemble the armrests of this wooden chair. And to screw the front part of the armrests, in the plans there are some rectangular pieces that should be screwed, from top to bottom, on the front legs and on the front armrest supports. Then the armrests would go on top of those pieces, and would be screwed from the bottom inserting screws from the rectangular pieces to the armrests.

Keep in mind that the size of these pieces depends on the thickness of the wood used. In addition, if we use these pieces, we have to put one on top of the front leg template when we use it to level the armrests (we will see it 5 images later). And I mean to put one of the pieces of wood, with the thickness corresponding to the wood that we use to make them, otherwise they would not be well leveled.

But instead, to screw the armrests I am going to use a different system than the one shown in the plans for this original Adirondack chair.

How to screw on the armrests of this wooden chair

So, what I’m going to do is to forget that rectangular piece that goes under the armrests, and I’m going to drill some pocket holes from the legs and from the supports.

So, I’m going to start by drilling holes with the same diameter as the head of the screws. But I drill only halfway. And then I drill the guide holes, of smaller diameter, inside the first holes.

Check that the screws do not protrude too far

Once I’ve finished drilling these pocket holes, I’m going to drive the screws into the holes and check that none of them will protrude more than the thickness of the wood of the armrests. To check it I use that piece in the picture, because it is not too heavy.

Though, before screwing them in here, first I have to screw the back of the armrests to the back supports.

So now I’m going to use the plywood template that I used to make the front legs of this Adirondack chair as a support to level the armrests. I adjust them in place and I insert, from the back legs, a couple of screws in each one. So it’s finally beginning to look like a real garden chair.

Screwing the armrests of the Adirondack chair

And now I can screw the characteristic Adirondack chair armrests to the front legs. I align the inner edge of the front of the armrest with the out side of the back supports, and I insert the screws in the pocket holes.

In theory, and according to the Adirondack chair plans I used, I would have already finished assembling the structure of this wooden garden chair. But as I showed in the previous post, where we saw how to make all the parts of this garden chair, I decided to also make some small supports to put on the back supports under the back part of the armrests.

Cut the small armrest supports at 45 degrees.

So, the first thing I’m going to do is to rip cut these supports lengthwise at 45 degrees. Something simple if I use my table saw jig to cut at 45 degrees. But I have to make sure that I cut them symmetrically, so I cut one with the wide part facing forwards on the jig, and the other with the wide part facing backwards. In the video you can watch better how I did it.

And now I can screw them in place, inserting the screws at an angle following the direction of these support. Although before inserting the screws I must make sure that the tip will not protrude from the outside surface of these small supports.

Adirondack chair seat and backrest slats

Screw the first slat of the Adirondack chair backrest

Once I have the Adirondack chair frame assembled, now I can assemble the backrest and seat slats. To do this, I start by screwing one of the outer backrest slats. Then, I want to align the outer edge of the slat with the end of the curves of the upper and lower backrest supports. And I want the bottom end of the slats to be a couple of centimeters below the bottom support. So, when I have the slat where I want it to be, I insert one screw against the top support of the backrest.

Measure to place the second slat in the correct position.

Next I put another slat on the other side of the backrest. This slat is symmetrical to the first one. Then, I have to align it the same as the first one, and measuring so that both are at the same height. And I put a screw against the upper support of the backrest.

Screw the lower part of the backrest slats together

Well, and I have to screw the two slats against the lower back support as well.

And here comes one of the most complicated parts of assembling an Adirondack chair: getting the backrest to be just right. But it’s a piece of cake with these couple of simple tricks that I am going to show you:

Tips for assembling the backrest of the Adirondack chair

The first trick is to nail a slat under the two backrest slats that I have already screwed in place. So now I can put the rest of the backrest slats at the right height without having to measure, mark or do anything weird (yes, I had to deal with some Adirondack chair assembly before, and the first few times it was crazy to get the backrest slats aligned with each other).

Assembling the garden chair backrest slats

And now here comes the second trick: If I find a thin piece of wood sheet that allows me to put all the slats of the backrest of this wooden chair at the same distance from each other, it is very easy to screw them all in place against the upper support of the backrest. I only have to start on one side of the backrest, and go forward, screwing one by one, until I get to the other side.

Lower part of the backrest of the wooden chair

I separate the bottom of the slats by eye, and I screw them against the bottom support of the backrest of this classic Adirondack chair.

Removing the slat that leveled the backrest slats

And now I can remove the slat that I had nailed in to hold and level the backrest pieces while I screwed them to the supports.

And finally I can assemble the seat slats of this wooden chair. So we can sit on it in the garden.

Notches in the first slat of the seat of the chair

Here we are going to see another small modification that does not appear in the Adirondack chair plans. The first slat that goes against the backrest bumps against the outer slats of the backrest, and like that it is too far forward. So I decided to use the jigsaw to cut a couple of notches. Even, to make the vertical slanted cuts, I tilted the jigsaw blade to make the vertical cuts at an angle. Now this piece fits better with the backrest slats.

Front of the Adirondack garden chair

Then, I put in place, but without screwing them, all the slats of the seat of this garden chair. And I make sure I have room to put them all. I adjust the decorated slat in place on the front of the Adirondack chair, and I fasten it with a couple of screws on each side.

Now I can also screw the slat with the notches into position. I put it at a few millimeters from the backrest. So, with the first and last slat of the seat of this Adirondack chair already screwed in place, I can put the rest of the slats back in between them. And I look for separators that allow me to leave them at the same distance from each other.

Seat slats spacers

In my case I found that the best spacers were the screws I was using. Except in the curve area, where I used washers as spacers.

And speaking of the curve, here we see how the slats do not seat well. In the previous post we saw how to cut three flat areas so that the slats sit perfectly. This is also not shown in the chair plans. But you can see here how I did it.

Screwing the wooden chair seat slats

Once the seat slats are in the right position, I can drill them a couple of pilot holes in each end and screw them in place.

As shown in the picture, in order to work comfortably, it is better to remove the armrests first.

And when I finish screwing them I remove the spacers.

Now, to finish this Adirondack chair assembly we would put the armrests back in place. But we still have to sand the wood and apply a protective stain.

How to finish the Adirondack chair assembly

The Adirondack chair is a wooden chair that will be a lot of time outdoors, in the garden in the sun and sometimes in the rain. That is why we are going to prepare it so that it does not spoil.

Numbering the seat and backrest slats

So, the first thing I have to do is to disassemble all the wooden parts. Fortunately, since the screw holes have already been drilled, reassembling the Adirondack chair will be easy and fast. But to avoid problems when I have to reassemble the back and seat slats, I am going to number them with a pen. This way, when I reassemble them, I will know exactly where each one goes.

Then, I number the slats and disassemble this lawn chair.

Countersinking the hole for the head of the screws

Now, to give it a better finish, I will first countersink the screw holes. This will ensure that the screw heads are flush with the wood surface. You have to be careful, as I drilled a lot of holes to assemble all the parts, and the screw heads only go in some of those holes. That’s why I have to pay attention and make sure I only countersink the right holes.

Continuing with the finish, the wooden chair will look better if I round some of the corners. Specifically I will round the corners of the armrests (except the area that is screwed against the back support), I round the corners of the armrest supports (also except the areas that are screwed against the legs and against the armrests), and I round the corners of the outer surface of the seat and backrest slats as well.

To round the corners I use the router table. And you have to be very careful, especially with small parts. It is advisable to use some kind of support or pusher to work more safely.

Sand all parts of the Adirondack garden chair.

I can now sand all the parts of the garden Adirondack chair with medium grit sandpaper and then with fine grit sandpaper.

Paint the chair with wood protector and stain for exterior wood.

And finally I can apply a couple of coats of wood protector and stain for exterior wood. When we use a brush to apply the first coat of a wood protector and stain, it usually does not look very good. But when we apply the second coat the color is more homogeneous and the marks of the brush strokes are not so noticeable.

A light sanding between coats of wood protector and stain is also recommended. This will make the wood surface of the Adirondack chair smoother.

When the wood protector and stain is dry, I can reassemble the Adirondack chair and start enjoying it.

You can see that assembling a classic garden Adirondack chair like this one can be a bit complicated and laborious. And along with the work involved in making all the wood pieces, we’re going to need a lot of hours to finish making an Adirondack chair. But if we think about the years we will enjoy it, if we are encouraged to accomplish this woodworking project, it is well worth the effort.

Read here all the articles on how to make an Adirondack Chair

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