Serger Basics: Serger Selection

Sergers are changing the concept of home sewing. Sergers, also called overlock machines, produce professional factory-like stitches similar to those seen in ready-to-wear garments. In addition, sergers are tremendous time-savers for home sewers. Sergers sew about two to three times faster than traditional machines, and they can replace three operations with one step by sewing, cutting, and overcasting a seam simultaneously.

A serger does use a needle (or needles), but instead of a bobbin the serger uses loopers. When the machine is operating, the looper threads lock around each other and are linked together with the needle thread to form the stitches.

Most sergers can make a rolled hem. A rolled hem is a narrow dense stitch made on the edge of the fabric. It gives a professional look, for example, to the finished edges of tablecloths, napkins, and ruffles.

Some sergers require a special plate and/or foot to sew a rolled hem. Others can be adjusted for rolled hemming without an attachment.

Types of Sergers

Sergers cannot totally replace the traditional sewing machine. They are designed to be used in addition to or in combination with a regular machine. Learning how and when to use a serger with your conventional machine is the key to successful sewing.

There are five basic serger machines, including these:

• the two thread
• the three thread
• the three/four thread
• the four thread
• the five thread

The two thread has one needle and uses two spools of thread. The two-thread stitch is primarily used as a seam or edge finish and is not designed to stitch a regular seam. Some machines can do a two-thread narrow rolled hem. The two-thread stitch also is used to do a flatlock seam where two fabric layers are stitched, then pulled apart so the seam allowances are flat inside the stitching. Some three-thread, four-thread, and five-thread machines can do a two-thread stitch.

The three thread has one needle and uses three spools of thread. It is considered a versatile and commonly used serger for home sewing. The three-thread stitch is used as a seam and as an edge finish.

As a seam, it is suitable for woven fabrics, but in areas of stress, stitching should be reinforced with a conventional machine. The stitching is excellent with knit fabric because it stretches or "gives" with the fabric. The three-thread stitch also can be used with specialty threads for a decorative finish. Both rolled hem and flatlock stitches can be made on three-thread machines.

The three/four thread has two needles and uses four spools of thread. It is similar to a three-thread stitch but for added durability has an additional line of straight stitching running through the middle of the three-thread stitch. It can be used to stitch seams in woven fabric even in areas of stress. It is also satisfactory for use with knit fabrics. By dropping one of the needles, this machine can do what a three-thread machine does, including the rolled hem and flatlock stitches.

The four thread has two needles and uses four spools of thread. This stitch is made up of a two-thread chain stitch that runs to the left of (not through) a two-thread stitch. All four threads are necessary to sew a serged seam. It is stable and suitable for woven fabric even in areas of stress and strain. However, it is not recommended for stitching knit fabric. The stability of the seam makes it a good choice for long seams with a lot of weight (such as draperies).

The five thread has two needles and uses up to five spools of thread. This machine can sew a two-thread, a three-thread, and a two-thread chain stitch. There are three loopers: an upper, a left, and a right. All five threads are utilized if seaming with a chain stitch and three-thread stitch simultaneously. Any of the three stitches can be isolated and used alone. Since the five-thread serger has not been as popular at the four thread, some manufacturers have discontinued the five-thread sergers.

Rolled edge hemming and flatlocking can be stitched with this machine. It is the most versatile of all the machines because of the possible variations. However, some people may find it more complicated to operate.

Knives

Two knives cut the fabric as it feeds through the machine. On most machines, the lower knife is stationary and the upper knife can be rotated out of the way when stitching in an area that does not need to be cut.

It is important that the knife blades are sharp. If the machine does not cut properly, it will not sew properly.

Consult your machine manual to determine how often to replace blades. Replacing blades depends on your sewing habits and the type of fabric you are sewing. Certain synthetic fibers dull blades more quickly than do other fibers.

If you use pins when sewing, remove them before they come in contact with the blades. Sewing over a pin with a serger can cause permanent damage to the blades, needle, or the presser foot.

Thread

Quality thread designed for serging is necessary. It is economical to purchase large cones or spools of thread in basic colors. Use the same brand and type of thread on all spools. This eliminates inconsistent stitching, thread breakage, and tension problems.

You can use other threads (such as buttonhole twist, two-ply baby yarn, metallic, narrow ribbon, embroidery thread, and pearl cotton) for decorative sewing. Experiment for special effects.

Thread Guide

Threading an overlock machine may seem difficult at first; however, with practice threading becomes simple and easy. Most machines for convenience have color-coded thread paths and a threading diagram somewhere on the machine.

It is important to thread the machine in the sequence specified in the machine's manual. Otherwise, the stitch may not form properly. For example, the threading order may be the lower looper first and then the upper looper and then the needle last.

When it's time to change the thread, a fast and easy way is to tie the new thread to the old thread at the top and run it through the machine. When the knot reaches the needle eye, cut off the knot and rethread the needle with the new thread. The lower- and upper-looper knots go all the way through the machine without problems.

It is a good idea to try threading different machines before you purchase one. Some machines are much easier to thread than others.

Needles

Some sergers use industrial needles instead of conventional sewing machine needles. These needles are available in various sizes for sewing on different weights of fabric. These needles have a round shank, so you must be careful to insert them correctly with the long groove in the front and the scarf in the back. If you insert the needle incorrectly, stitches do not form properly.

Some sergers use conventional sewing machine needles. These needles are easy to insert, since one side of the needle is flat at the top and fits into the machine only in one direction.

Tension

Each thread on the machine has a tension dial it must go through to control thread movement. Tension dials are located on the inside, outside, or set into the machine. Most are numbered or color coded to help gauge tension.

Stitch Width and Length

On most sergers, you can vary the stitch length and width settings, and adjustment depends on the brand of machine.

To alter stitch width, some machines have an adjustment on the throat plate, while other models require a change of the throat plate. On others, width is adjusted by using either the right or left needle.

To alter stitch length, it may be necessary to loosen a screw, push a button, turn a dial, or move a lever-- depending on the individual machine.

Important factors to look for and consider about stitch width and length are the ability to be adjusted, the ease of adjusting, and the stitch quality.

Special Features

Note any special features on the machine, such as free- arm models, special tables, dust covers, travel cases, carrying handles, trays for trimmed-seam allowances, accessory case contents, and built-in storage for basic accessories such as tweezers, cleaning brush, and needles.

Note also, seam allowance markings on the machine, direction of handwheel rotation, and ease and comfort of foot control use. Review instruction booklets carefully to be sure they are clear, complete, and easy to follow.

Most of today's sergers come with a feature called "differential feed." Sewing machines with differential feed are equipped with two feed dogs that move independently. When the setting is normal, both feed dogs move at the same speed. This is the setting for most fabrics and procedures.

For knitted or bias-cut fabrics, the front feed dogs are set faster, which prevents puckering or waving during sewing. By slowing the front feed dogs to a slower than normal setting, it helps to prevent lightweight or sheer fabrics from puckering. When the front feed dogs are set at a speed faster than the earlier setting (2 to 1 ratio), they are feeding in much more fabric than the back-feed dogs can feed out. The obvious result is that the fabric will be eased or gathered, depending on the setting. Practice settings on scraps to determine the desired results.

A growing number of late-model sergers come with automatic threading systems. In this system, looper threads are placed in a threading port, and an instant "jet-air" system completes the threading process. This threading technique assures greater accuracy and is a tremendous time saver.

Care

Serger machines must be kept lint free and oiled frequently. A great deal of lint is produced as fabric is cut. Compressed air, available where sewing notions are sold, is the easiest way to remove lint from the machine. Check the manual for frequency of oiling.

Selecting a Serger

Many brands and types of home serger machines are available. Don't be in a hurry when shopping for a serger. Make a checklist and compare different brands and models. The chart provided lists items to consider when buying a machine.