Paul from SWISCO responded:
November 8, 2017
For a wood sash balance system, we suggest our Series 500 balance with a 17-012 bottom bracket. This system has been used by the wood window manufacturers since the 1940's. You would rout out a 5/8" groove on the side of the sash for the balance tube. To determine the balance length, you would take the glass height and add 1" for the top sash and 3" for the bottom sash. We don't recommend coil springs for these windows. Below are generic directions for the Series 500 balance system:
"For your wood sashes, you will need our Series 500 balances with 17-012 balance brackets. These brackets hook on the balance spiral. To install these balances, you would drop them in from the top, on the side of the sash. Use a 33-017 screw to attach the balance tubes at the top. Now raise the sash and have someone hold it up, while you attach the 17-012 bottom bracket with a 33-090 screw, while the U-shape opening corrals the spiral. With your finger, lift the spiral up to the bracket, attach the 75-005 tool, and turn the spiral clockwise three turns, hooking it into the fork of the bracket. Repeat on the other side and try the sash. If the sash creeps down, raise and hold up the sash, giving the balances another turn or two." |