Spirals

Thanks for posting. I am not certain myself, as these windows are obviously very old, but I'm running your question past some of my senior colleagues, and we'll get back to you as soon as we can with more information. Thanks. 

One of the oldest and still used today is Series 500 non tilt balance for wood sashes. The formula to determine the sash balance length for a wood window is to add three inches to the height of the glass for the bottom sash, and 2" for the top sash. You gave a sash height of 36",so I estimated the balances for the top sash to be 34" and the bottom sash 35". For the sash weighing 34-35 lbs, go with black tip balances. They hold sash weight up to 40 lbs. You would use the 17-012 bracket with this balance. 

For installation, you would screw the balance tube at the top of the window track with the 33-017 screw. Raise the sash and have someone hold the sash up while you screw the 17-012 bracket on the bottom of the sash to corral the spiral. To screw in the bracket, use the 33-073 screw. Now hook the end of the spiral with the 75-005 tool and give it about four turns. Then lock the bow tie at the end of the spiral to the the 17-012 bracket. Do the same on the other side and try the sash. If it creeps down, give the spiral another turn. 

Hey, Dusty. We have a detailed price breakdown for each part Paul suggested on their respective store pages, including quantity discounts.

Paul estimated you might need the S500-34 and S500-35, based on the sash heights that you provided. If you click on those links, you'll see both balances have Black Tip options. Let me know if you have further questions.