This chair was inspired by one done by LIGNUM (Pixel lounger) that I viewed on Youtube. I loved the look but wanted to do a chair instead of lounger and also wanted to change the construction to make it lighter. Both are made from plywood but LIGNUM's is monolithic. I made this chair hollow to save materials and weight. The basic concept is to construct 2 side structures from different length slats wherein you can create holes of different sizes and shapes and then tie the sides together using cross pieces that will also be the seating surface front, bottom and back rest.
A great aspect of this project chair is that it does not require any clamping when gluing the pieces together during assembly. Instead of clamping after applying the glue, you simply nail the pieces together with a pneumatic brad nailer to hold them tightly together as the glue drys.
So off I went and the attached pictures show the result. I'm extremely pleased with how it turned out.
Step 1: The Design:
The first step in the process is to make a design plan to reference throughout the build. It should consider not only the aesthetics but the proper dimensions so as to be comfortable. You can create this in many types of design softwares or even PowerPoint or just hand draw one. My design and dimensions were based on my taste and size. By the way, as is usually the case in any project, I did take the liberty to make some changes in the aesthetics as I went along to better balance the look.
Remember that this will be your project and design. You can use my design or use your own creativity to effect a unique design of your own. If for example you like the appearance of the through holes but think it could be done differently or better, go for it. You can also select the lengths of the slat pieces that make up the sides of the chair or build it with completely random piece lengths.
Next,create a full scale cardboard template to use as a physical pattern to layup the actual chair sides. I drew a grid on it to be able to help determine the locations to put pieces and laid cellophane over it to prevent gluing the chair side to the template.
Step 2: Tools and Materials:
You will need a decent array of power hand tools to help make the work manageable, especially the contouring of the seating surfaces and the sanding of all surfaces.
- Electric hand planer
- Hand held belt sander
- Orbital sander
- Small (2") pneumatic right angle sander
- Electric 4 1/2" right angle grinder
- Small router
- Pneumatic brad nailer
- Chop saw
- Table saw
- Disc sander
As for the materials, there were just a handful needed:
- (2) sheets of 4' x 8' high quality 3/4" plywood (Baltic birch or "Whitewood"). I used the "White wood" I found at Lowes but a furniture grade birch is a little nicer. The key is that you will have the edge grain exposed over most of the chair and you want this to look as nice as possible (no voids or crude lamination's exposed). The photo shows the plywood already cut into the 2 basic raw components (2 3/4" wide side material strips and 1 1/4" wide seat material cross pieces). See drawing for how I cut up the plywood into the basic pieces (side slats and seat cross pieces. It should be noted that I started by having Lowes cut the 4' x 8' sheets into 2' 4' panels for easy of handling and cutting in my small shop.).
- Wood glue (about a quart).
- 1 1/4" steel brads for use in a pneumatic brad nailer.
- Sanding supplies;
- Lots of 60, 120 and grit 220 sanding discs for the orbital sander.
- Lots of 40 and 120 grit sanding belts for the belt sander.
- Lots of 2" 40 grit sanding discs for the small pneumatic right angle grinder
- Carbide grinding disc from Harbor freight for rough contouring.
- Several 60 and 120 grit 4 1/2" flapper sanding discs for finer contouring
- Wood filler ( do not use "non-hardening" filler)
- Protective finish (I used Krylon clear aerosol)
Step 3: Construction Approach:
The assembly is quite simple because the glue up does not require any clamps. Instead of clamping, each slat piece is first glued up and then immediately nailed to the assembly stack up with a pneumatic brad gun using 1 1/4" steel brads. This makes the assembly process very efficient. Also It helps to pre-finish the slat pieces with a stationary disc sander to reduce finishing efforts and making for a cleaner overall design.
- Start the process by laying each piece on your template being sure to have the ends of the pieces match up with the contour. Remember that the cross pieces will glue into the notches created along the contour line. This is where you will be able to see how much overlap you have between each cross piece. Having glued overlaps is what will give it strength by sharing loads with the adjacent pieces.
- Take your time to be sure that the 2 side assemblies are geometrically and dimensionally the same so that when you tie them together with the cross pieces, the cross pieces are aligned and parallel with each other. I also took a picture of the first side and used it as a reference to make the second side (see picture of assembled side)
- Apply glue to both pieces being glued together and while carefully holding the new piece in it's proper location, nail it to the assembly. Wipe off excessive glue and move on to the next piece and repeat the process.
- You will end up with 2 side assemblies. Stand these up on a flat surface as they would be positioned in the chair. Tack several cross pieces in place in different location to hold the relationship between the 2 sides while you begin to install all of the cross pieces. Be sure to measure the spacing so that the two sides are parallel and also check to be sure that the sides are square with the surface they are sitting on.
- Now you can begin gluing and nailing the cross pieces in place. It is important that each cross piece overlap it's neighbor by at least 1/2" so that there will be sufficient bond strength between the two.
Step 4: Finishing:
Now the work begins. I'm not talking about a complicated task, just one that takes patience and some elbow grease.
- First place and thumb tack the template you used to assemble the sides onto each side assembly and trace the outline onto the wood with a dark pencil. This will be the general line you will plane, grind and sand down to. It's not important to actually remove all of the material down to the line. It only matters that the contours have nice geometry and the straight areas are straight. This will be important when you begin final sanding because correcting for deviations in the contours or flat areas will be more difficult.
- Start sculpting the surfaces by using a hand planer (electric ones save a lot of time) to mill off the "toothed" profile of the rough contour. Try to get to the point that there are no valleys/grooves between each cross piece.
- Next take a belt sander and sand the flat seat, front and back areas smooth and flat and sand the convex contoured areas until they are smooth and even.
- Next use the right angle pneumatic grinder and electric right angle grinder and sander to rough out the concave contour. Once this is done you can use the end of the belt sander and the orbital sander to achieve the final concave profile.
- In order to have a symmetric gentle transition from the sides to the seat, take a router and "round over" bit and carefully route this edge. It is important to turn the chair on its side and route the edge with the router base riding on the side of the chair and the router guide bearing following the seat contour.
- A step that I used but that is optional here is to paint all of the through holes in the sides and the inside of the chair. To me, this makes for a much cleaner looking design and the color adds interest, contract and can match your decor..
- The next to the last stage is putting the final sanded finish on it. Most of this should be able to be achieved with the orbital sander. Start with a coarse grit like 60 and then move to an intermediate grit like 120 and then finish with 220.
- Start by sanding the sides. Sand down the ends of the cross pieces flush with the sides and sand away any paint that may remain around the edges of the holes. Carefully use the orbital sander in a rocking motion to sand the radius between the sides and the seat.
- Next concentrate on the seating surfaces. Use your sense of touch to find any imperfections and continue sanding until complete smooth. I used a wood filler to fill any voids or imperfections in the plywood and sanded them until they were not noticeable to the eye or touch.
- For the final stage you can need to apply a protective surface treatment such as an oil or stain/polyurethane etc. Oils will darken the appearance a good bit and stains will really darken the appearance (I highly recommend against it because the plywood end grains absorb the stain at different rates and it can look very uneven). Also the stain will penetrate very deeply and be very hard to sand out if you do not like the look. I simply applied 2 coats of a spray on clear aerosol by Krylon from Lowes. I love the very blonde look of the sanded plywood and this clear spray worked great to help keep that look.
Step 5: Admiring and Enjoying
I have to tell you, it was a little nerve racking for me during this build because I had no experience with plywood or a design like this. I trepidated a great deal in anticipation of issues that I might not be able to work around. But although I did have to make some adjustments on the fly because the two sides were not dimensionally and geometrically as identical as I would have liked to have made them, the basic build was pretty straight forward. So having said that, I'm so please with the results. The design is clean, ultra-contemporary, dramatic, stylish, and comfortable. People are drawn to it when they see it and most of all the end grain of the plywood makes everyone walk up and inspect it for the beauty that that imparts. Have fun and I hope your efforts will be as satisfying as mine were.
Second Prize in the
Furniture Contest 2018