Here's a few more things I've learnt on the way.
Today I ordered a cording/piping foot for my wife's sewing machine DZ1141 Universal Metal Double Welting Piping Cord Foot FOR Singer Brother Janome | eBay. Almost all good upholstery needs piping, mainly just to disguise the messy bits where surfaces join. Its usual to make your own piping from the same fabric as the chair covering and a bit of twine or whatever. Last time I used a zipper foot on the machine, which was OK but cant really get in as close as I would have liked and thus there was some puckered-up piping. The cording/piping foot actually has two grooves in the foot, one on either side of a tiny needle cut-out. As the sewing progresses, the twine is guided through one of the grooves and the needle punches through the cutout right beside it. I think the second groove is for doing double piping - though not sure about that. Its worth getting one of these things apparently.
Be careful to buy a cording/piping foot, not a cording foot, which I did previously and is something quite different.
Also, dont forget to cut your piping fabric on the bias.
I also made a staple remover. Its just an old screwdriver with the end ground into two sharp points, and bent after heating with MAPP gas. If you keep the width across the points less then 9mm then you can drive either one or both prongs in below standard (T50) staples. I have found about 25 degrees being a good angle for the bend, enough leverage without feeling misaligned when you drive it in. On one Youtube video the guy said he uses it in his left hand and drives it with a pair of pliers in his right, rather then a hammer. That way he doesnt have to go searching for his pliers to pull recalcitrant staples. It works very well. Another tip from the same guy was to keep a magnet or two on the benchtop when de-stapling, sooner or later all the staples end up sticking to it, making cleanup easy. I guess when you have thousands to do every bit counts.
Attachment 395952
I also found that this site is the best way to learn about chair/sofa woodwork - Clark Chairframes cover. You can see everything here, naked of upholstery.
Chairmaking is not the sort of careful woodwork we are used to - like screws driven straight into endgrain and joints clamped up with nailguns. I was a bit taken aback at first then I decided that clearly it works so when in Rome ...
And finally, here's an interesting picture of a chair frame with the components named. About the only thing which is not intuitive to a woodworker is probably the stretcher rails. These are the components to which the upholstery is stretched down and then tacked, so they need to be robust and set in such as way that they dont interfere with the alignment of the fabric.
Attachment 395953
cheers
Arron