How to Stuff and Sew a Buggy Seat Cushion | Engels Coach Shop 

David Williams, I couldn't have said it better, my friend !!

Would like to know what is going to keep the top of those springs from wondering all over the place? We used to tie the springs to keep them in place. It was an art in itself.

@@EuphJL That is an excellent question… these are Bonnel type (double cone or hourglass shaped) springs. Their base is the same diameter as their top. Unlike Leggett coils, (single cone or tornado shape) that have a very narrow base they are very stable under load. There are a few factors at work. First off, their base is very stable once stapled to the seat. Second the materials that he used are not like the Dacron, polypropylene fabric and polyurethane foam we use today. The burlap is fibrous and it’s open weave allows it to mold around the particular shape of the coil top. Then, the wood fiber filler (or excelsior, as it was also called) is stiff enough to bridge across the gap between the coils and provide support. Yet, it is pliable enough to ‘pocket’ into the top of the coils and lock them in place. Traditionally, horsehair, straw and even coconut fiber would have served the same purpose. From the point of view of the spring in use, another huge factor is in play. If he had used a single cone coil… as they are compressed the largest diameter turns of the coil collapse first. These are at the top. As they do they are constantly trying to push away from their vertical axis and fall over. By the time they are fully collapsed they are a wobbly group of spring loaded nervous prisoners trying to escape the downward pressure in any direction they can go. That tends to cause them to wear away the burlap and fiber on top. A double cone coil has its smallest diameter in the center. When compressed the top and bottom turns collapse at the same rate. This transfers any tendency to wobble to the center of the spring. Because the force is equal from both directions, the center does not try to push out of alignment and the spring collapses straight downward. A last factor has to do with the seat itself. In most box springs or chair frames the bottom of the springs are mounted to wooden slats or a metal frame. That means there are openings between their bottoms. When a curved object, such as a persons posterior, presses down on the seat… the cotton padding & wood fiber tends to push into the openings or voids beneath the spring. That causes them to shred and the spring will eat its way through them, eventually. That is the second reason the coil tops are tied together… to bridge the gap. Elaborate grid works of wires and springs have been devised to serve that purpose. And you are correct, the art of the standard 8-way hand tie is a thing of beauty! This is not necessary in Dave’s application because the seat is solid with no voids to fall into. Curiously, if he had used stronger springs or more of them they would not collapse totally under the passengers weight. And, they would have torn right through the filler and padding above. Like I said, you asked an excellent question. Those old coach builders knew a lot more about how things work than we will ever relearn!

@@sassafrasvalley1939 an expert has such incredible knowledge. We learn how little we know about the subject. Amazing how complicated getting a seat cushion right can be!

@@theoldbigmoose truth! I know people who have spent their entire careers just studying and trying to figure that out!!!

@@sassafrasvalley1939 An excellent explanation! Thank you! Still in all, if this job had come through our shop I would have done a four way tie on the springs just to make sure.

I really wish one of his family members would step in and tell him to stop wearing a jean shirt with jean pants.

@@chunulusbungulo5045 Why, they are color coordinated, or am I missing something?

The machine you had might have been out of time. A sewing machine, like a gas engine, has to be timed for all of the movements to work correctly. The sewing machine my wife & I bought just after we got married started breaking needles and it was out of time but it won't stay in time so I think one of the gears is slipping on its shaft.