Well my computer chair seat cracked a while ago, and I tried a "quick fix" by screwing some scrap wood flooring pieces on the bottom. But that didn't work all that well... So I needed to either get a new one, or fix it for realz.
After shopping around a bit, I decided I'd just fix it. Mine isn't any particularly good chair, but I like it, and I don't like any of the affordable ones I saw, so it's worth it to me to fix.
Step 1: Stuffs You Need.
• Plywood – Use ½” plywood if possible, thicker is better.
• Foam – Use what you’ve got, I happened to have some 2” memory foam laying around from a project I’d done before… Cushy…
• Fabric – once again, use whatchya got, I wanted to use black so it’d match, but no dice. So I used some came I had around (once again, from a different project).
Remember, the name of the game is cheap. Don’t buy nothing you can avoid buying.
Step 2: Strip It Down
Step 3: Makin the New Seat.
Take the old seat, sit it on your foam and trace it out. For me, I couldn’t quite fit it, so I just cut it as close as I could.
Then I sat the foam on the plywood and traced it out, then cut it with a jigsaw. As you can see, it’s not really good looking, so I took the plywood to the belt sander and rounded it out and made the overall shape a lil’ smoother. Then I sat it on the foam and cut it to fit. Complicated enough?
After all that I just ran over it with some 100 grit sandpaper to smooth out the edges n all.
Step 4: Drilling and Fitting
Set out the chair frame on the seat where you want it, and when it’s in place mark the holes with a sharpie, then drill out holes for the nuts that the bolts fit into. Make sure you C’bore the top side of the holes so they sit down in there flush. For mine I used a 3/8” bit for the holes and a 5/8” for the C’bore. Test fit it all together to make sure the bolts don’t stick up and everything works like it should.
Step 5: Upholstery!
Make sure you’ve got the nuts installed before you do this!
Fortunately, it’s pretty easy to do. Just cut the fabric so it fits over nicely, lay it over the foam on the seat and flip it all over. While stapling it all up pull the fabric tight. That keeps wrinkles off of the top, and smooths over the foam. Makes for a nicely domed top. After that just trim the fabric about ¾” from the staples so it doesn’t look too messy and you’re good to go.