In CRAFT, volume 07, we ran an http://www.craftzine-digital.com/craft/vol07/?pg=134&pm=2&u1=friend">Upholstery 101 by Ashley Jameson Eriksmoen. In it, Ashley showed how to replace the seat cushion on a dining room chair. There wasn’t room to include some of the details, like sewing your own welting, or slotting or webbing the seat to make it more comfortable, but I realized that Mending Month was the perfect time to share the extra how-to! (You can still buy Volume 07 in the Maker Shed, too!)
Webbing, Slotting, and Welting Techniques
Bar clamps or C-clamps (2)
Drill with a ½” twist bit
NOTE: Many drills only accept drill bits with shanks up to 3/8″, so buy a ½” drill bit with a stepped-in 3/8″ shank.
Jigsaw with blades for thick wood
3yds 3½”-wide jute webbing
Webbing stretcher You will need a webbing stretcher to get it tight enough.
1/3yd fabric for welting
2yds ¼”-diameter welting cord
NOTES ON TOOLS AND MATERIALS
Ripping chisels and tack lifters are used to loosen and remove tacks, while staple removers are used to lift staples. An oyster shucker can be a useful replacement in both cases. For stubborn or broken fasteners, a pair of ripping pincers is useful, but a regular pair of needlenose pliers will work just fine.
If you are webbing, a webbing stretcher is necessary. Webbing cannot be brought under sufficiently even tension by hand pulling.
I use a pneumatic upholstery staple gun, a BeA 401. It is made for much lighter-weight staples than a carpenter’s stapler, and operates at a much lower pressure, around 80psi. I prefer this type of stapler because it’s easy on the wrists, fast, and gentle on the fabric. A carpenter’s stapler is overkill; it will damage the fabric, possibly tearing right through it. You can use a manual staple gun, but it might tire your hands and wrists if you do much upholstery. I actually prefer tacks to a manual hand stapler because they’re just as fast and easier on the hands. Tacks are the most traditional, and least expensive for startup costs. You just need an upholsterer’s brass tack hammer with a magnetic tip, and a box of tacks. Any stapling operation described in the article can be accomplished equally well with tacks.
When cutting foam, it’s important to make the cuts nice and square. I use an inexpensive electric turkey slicer to cut foam. It works beautifully. If you happen to have a band saw, that works great too, but try to keep the dust and wood chips off your foam. Scissors work fine for foam 1″ thick or less, but create a jagged edge on thicker foam. One way to avoid this problem is to work in layers of 1″ foam, stacking foam for thicker seats rather than trying to work with thicker foam.
There’s a lot of gorgeous fabric, but it’s not all necessarily appropriate for upholstery. Upholstery fabric should be a weave, never a knit, and should have very little stretch in either direction along the grain. It should be sturdy enough that it will withstand having staples put in and ripped out. There are upholstery-weight silks, but they need to be backed and they’re not as resilient during the process of upholstering, let alone surviving as dining chairs. Jacquards, brocades, denims, and heavyweight woven wools are all good choices. Go to a fabric store with a home décor/upholstery section and walk right past the quilter’s print calicos, dressmaker’s silks, and chintzes for curtains, until you get to the more substantial fabrics. Stripes and plaids add extra challenges of perfect alignment, so there may be some extra staple ripping and redoing if you choose these linear designs. Solid colors or nonlinear, all-over prints are the most foolproof. (Leather, naugahyde, and vinyl require their own set of techniques, which I will not cover in this article.)
Plan A: The Webbed Seat
You’ll be cutting out the inside area of the chair seat to create a frame at least 2″ wide, and then webbing the donut. Webbing is a really useful skill in upholstery that will come in handy for more complicated chairs.
Step 1. With ruler and pencil, measure and mark 2″ inside the entire perimeter of the underside of the seat. Here, the line is nudged in to account for the chair leg notches. Clamp the chair seat to the edge of a workbench so that half of the seat overhangs the edge. Use both clamps and crank them down tight. Locate 4 “corners” on the inside edge of your drawn outline. Put your safety glasses back on. With the ½” bit in the drill, drill starter holes along the inside edge of your line at 4 corners of the frame.
Step 2. Install an appropriate wood cutting blade into the jigsaw. Place the blade through the starter hole, and hold the base or “shoe” of the jigsaw firmly against the wood. Switch the saw on and follow the inside edge of your drawn line until you arrive at the next corner hole. Turn the saw off while you reposition and clamp the seat for the next section of the cut.
Repeat previous steps until center section is out.
Step 3. Mark the centers of the front and back of the seat, and determine the number and spacing of webbing strips. You’ll want to work with a full length of webbing rather than pre-cutting short pieces. Fold the end of the webbing back 1″, and place the folded edge ¼” inside the back of the seat frame. (Fold at an angle for round seats.)
Place a row of 5 or 6 staples across the webbing. Then draw the webbing across the frame opening to the front of the seat.
Place the rubber end of the stretcher against the outside edge of the frame, angle the stretcher up, and catch the webbing on the stretcher spikes. Bring the stretcher down low to tension the webbing.
Holding the webbing taut, quickly lay down a row of staples. Release the stretcher, fold the webbing back over itself, and place an additional row of staples across the webbing. Trim the end.
Repeat until 2 or 3 strips of webbing are stretched front to back.
Step 4. Weave the webbing over and under the previously attached strips, fold back the leading end, and anchor it to the side of the chair frame just as before. Stretch the webbing across the chair as before, and staple. Repeat until the weave is complete.
To finish, cut a piece of burlap 3″ wider and longer than your seat pan. Center it on the seat, and staple it to the sides, pulling it taut and folding the edges under as you go.
Plan B: The Slotted Seat
Sometimes a chair seat is ½” thick or less, and won’t hold up to webbing. You can still give it greater spring by incising slots into the seat.
Step 1. After stripping the seat pan, mark an outline 2″ inside the entire perimeter. Then map out lines from front to back on the seat, evenly spaced approximately 2″ apart. Clamp down the seat pan so it overhangs the edge of the workbench, and slip back into those safety glasses. Drill ½” holes at the corners and intersections of your drawn lines. You will have to reposition and re-clamp the seat in order to drill all the holes. These holes will be the endpoints for each front-to-back slot.
Step 2. Secure the proper blade for wood into the jigsaw. Thread the jigsaw blade through the drilled hole. Hold the saw base flush against the wood seat, and start the saw. Be sure to cut only along the front-to-back lines. All cuts should be parallel lines; no wood is being cut out of the seat, so don’t make cuts across the front and back edges of the seat. You will have to reposition and re-clamp the seat in order to complete the cuts.
You can see that the seat is much more flexible now.
Welting can be added to the edge of any slip seat that rests on the top of a chair frame. It can be done in the same fabric as the seat, or in a contrasting color. Often, notches benefit from the camouflage of welting. Seats that sit below the top of the frame, down in a well, are not suited for welting detail.
Step 1. Measure the seat perimeter, including the lengths of any notches, and add 12″. Cut this length of welting cord, and a strip of fabric that’s the same length and 2″ wide. (Traditionally, welting is cut on the bias, meaning diagonal to the grain of the fabric. This takes a lot of extra fabric, so I often cut welting straight with the grain.) If you can’t get the length you need from a single piece, you’ll need to sew strips together. To avoid a bulky spot in the welt, sew the seam diagonally so it spirals around the cord. Place 2 strips of material across each other so they’re perpendicular, right sides together. Sew corner to corner, across the square intersection of the 2 pieces. Open up and iron the seam open, then trim it ½” from the stitching. You now have a nice long strip of fabric.
Step 2. Put a zipper foot or a cording foot onto your sewing machine. Place the cord in the center of the 2″-wide fabric strip, and fold the strip over the cord. Butt the zipper foot right up against the swell of the cording, and begin stitching.
Hold the cord tight inside the fold by keeping 1 finger inside the fabric. Sew the entire length of the strip to make your welting.
Step 3. Begin at the center of the back of the chair, about 3″ in from the end of the welting strip. Staple the welting into place so that the corded side is flush with the edge of the seat, and the staples are close to the seam.
It can be tricky going along the notches; get the nose of the staple gun in there and staple the welt to the sides. Staple all the way around, stopping 3″ from your initial starting point.
Snip the welting cord so that it overlaps the other end by 3″.
Using a seam ripper, or carefully using the tips of your scissors, rip open the seams 2″ back on both ends of the welting cord. Open up the starter end of the welting so it lays flat, then fold back 1″ of fabric to create a hem. Open up the finished end of the welting and lay that fabric flat down on top of the first end. Now lay both ends of cord down the center of the fabric strip, and snip the cords so they barely touch.
Fold the 2 layers of fabric so they wrap around the welting cord to form a neat, continuous piece. Finish stapling the cord into place.
Photography by Sam Murphy
About the author
Ashley Jameson Eriksmoen teaches upholstery, woodworking, and furniture design at City College of San Francisco, California College of the Arts, College of the Redwoods, and craft centers including Penland School of Crafts in North Carolina and Anderson Ranch Arts Center in Colorado. She designs and builds sculpture and furniture at her studio in Oakland, Calif., and exhibits nationally. ashleyeriksmoen.com