By Chris Wantuck
This is the first in a series of articles dedicated to Automotive Upholstery for Beginners. In this series we'll take you through the basics and show some projects that will hopefully help in your classic car restoration efforts. We can't cover all upholstery techniques, but with the understanding of the basics you should be able to tackle many sewing and upholstery related tasks. This first installment discusses the "hows" and "whys" of machine set up.
In a gathering of Do-It-Yourself (DIY) car guys (and gals) discussing auto restoration, they most likely would be talking about things like engine rebuilding, suspension, panel fabrication, painting or electrical systems. Mention upholstery and watch their faces turn from enthusiastic to frowns. A typical response is "Oh, I'll just purchase a kit for that." Of course that's great when a kit is available for your model, but what if your project is old or exotic enough that an upholstery kit is not available. You're stuck. Then you have three choices: reusing the original upholstery; tackling it yourself; or sending the car out and paying a professional. Granted a professional may have many years of experience and likely could do the job faster and with a degree of quality better than a beginner. But that service comes with a price. It's not hard to imagine that getting your project restored to this point may have stretched your budget, and adding another $5-10K or more isn't possible. There are many books about upholstery available. In each, the author presents the material, covering subjects that he thought was important and often the book is geared toward a certain era. That's not a bad thing. But what they often miss is a thorough explanation of the basics. Those interested in rounding their restoration skills by learning upholstery, this series is intended for you, starting with the fundamentals.
Since so much of the upholstery trade involves creating seams using a sewing machine, we'll start with that and then include organization, tools, hardware and supplies as needed. Here are some sewing machine definitions, terms, and notes that you should know:
Machine Head The sewing machine unit (referred to as the Head) sits in the table typically with two hinge points at the rear and the weight of the Head provides tension to the drive belt. This JUKI unit is a well known Japanese commercial brand (Photo 1). It is called a compound walking foot (more on that later). The table height can be adjusted to fit the operator.
Photo 1 Overall view of a JUKI brand sewing machine (called the head) installed in a special table. JUKI is a Japanese built machine and is well known in the upholstery trade as a high quality machine. Note the light on a gooseneck arm to put light where it's needed. The table is special as it has adjustable height, includes hinges on the back of the motor head to tilt it backwards to access the bobbin and clean the bottom tray. Other features are the hand wheel on the far right, the reversing lever (horizontal bar on right), bobbin winder on right, and needle on far left. Notice that the table and machine are located against a long table used to catch the material as its being sewn. Under the table are attached the motor, clutch, knee lift and treadle.
Motor The electric motor under the table runs at a constant speed and uses a side slip clutch (Photo 2) to drive the pulley and belt to the Hand Wheel. Motor speeds can be 1750 or 3500 RPM. Beginners should select a machine with a motor at 1750 RPM to get better acquainted sewing at a slower speed. One suggestion, a pulley and belt arrangement can also be included for further speed reduction (Photo 3). The belts can be later arranged to speed up the machine speed when you feel comfortable stitching at the slower speed.
Photo 2 The sewing machine motor is a heavy unit which operates at constant speed. Most motors run at 1750 RPM but certain machines can be configured with 3500 RPM motors. The faster motor should be avoided when purchasing a machine for the beginner upholsterer. On the right side is the side slip clutch with a spring tension adjuster. Below the motor is the clutch lever that engages and brakes the machine. The threaded rod is used to adjust the tension to the belt pulley.
Photo 3 This belt and pulley arrangement was installed to intentionally slow the motor's speed to the machine. As configured, it slows the 1750 RPM motor to about 1,000 RPM and if needed the belts can be slid to different pulleys to raise the speed. The pillow blocks, shafts, belts and pulleys were purchased from McMaster Carr and Grainger.
Treadle The treadle is the foot operated platform that drives the motor's clutch. Using both feet, pressing the treadle forward (rotating forward & down) engages the machine and using the heel backward disengages the clutch and applies a brake to stop the machine (Photo 4). After a while, you will learn the sensitivity of the treadle: when the clutch engages to operate the machine at either a slow stitching speed or at full speed but for short bursts. There are position and spring tension adjustments associated with the treadle. Take the time to adjust these to suit yourself.
Photo 4 The treadle is a foot actuated platform that engages the clutch. Pressing (more like rotating) the feet forward engages the clutch and pressing backward with the heels applies the brake. The brake is applied when the operator needs to reposition material to be fed into the needle or when pivoting. Note the different positions the tread rod can connect to the clutch arm and the two locking nuts that adjusts when the treadle engages and brakes the motor.