Expert: Mark H. Miller - 3/10/2010

Question
I am reupholstering a chair that has zig zag springs in the seat.  This chair is approximately 50 years old but the springs are not broken.  The problem is, I like a bit more firmness than these springs give.  I saw an answer that you gave that zig zag springs don't wear out.  What can I do to firm up this seat.  The springs look brand new and fit your spacing guidelines that you gave.

Answer
Hello Lynn,

There is only one way to make a zig zag seat firmer,  and that is by connecting all the springs together so that they work as one solid unit rather than as individual springs.  

This is done with either rubber bands or small springs called helical springs.  Both should be available from upholstery suppliers.  Type Upholstery Supplies into any Internet search engine and several sources will come up.  Look for no-sag springs and the rubber bands or helical springs will come up.   Otherwise contact Beverly upholstery supplies in Los Angeles.

It is best to place the rubber bands or springs working from the top of the seat with nothing covering over the springs - you can not do this job working from the bottom of the seat.  My first choice is the rubber bands,  loop a rubber band over a spring loop and then hook it over the spring loop of the spring next to that,  you would do that to every other loop so that a rubber band will go to both the spring to the left and to the right starting in the center.  It's hard to explain but when you begin the job it will become obvious what I am talking about,  place as many rubber bands as you can fit.   If you can't locate the rubber bands use a bicycle inner tube and cut about 1 inch wide bands - it's the same thing.

After you do that you will notice that the springs are all pulling toward the center away from the side edge of the chair - that's exactly what you want,  you now need to straighten the springs back to their original shape without the curve that is caused by the rubber bands.  

To achieve that you are going to work only on the last row of springs the one on the very left and the one on the very right,  start at the back of the chair and work toward the front of the chair.  Loop a strong twine around the spring loop that is closest to the outside edge,  pull the twine toward the side of the chair.  Put a nail into the top of the frame so that about 1/2 inch is still out and loop the twine around the nail and then drive the nail down into the frame,  repeat that for every spring loop so that the springs are back to the original shape they were in when you placed the rubber bands.   Repeat that for both sides.   

The best nails for this are called no-sag nails and you should be able to buy those from the same source you bought the rubber bands.  Otherwise look at the nails that hold the spring clips in place and use the same size nail.

Then place a layer of padding material over the springs and then burlap.  And pad as before -  your seat will now be at least 50% firmer.   If you are unable to locate the rubber bands use the helical springs - they are available from some hardware stores under that name, and do exactly the same thing as with rubber bands.

I hope this helps.  Please don't hesitate to contact me if you need further pointers.

Mark Miller.