While most of the windows on historic buildings built before WWII used the simple and effective rope and pulley counterweight system there are some that utilize different balances systems. A popular option were spiral balances, sometimes called a tube balance, and that’s what we’ll talk about today.
These balances are not terribly complicated, but they can be troublesome to work with if you’re not familiar with them. I’ll be speaking specifically about one of the more common types I’ve come across, but there are dozens of variations made by several manufacturers.
The advantages of these balances is that they are a relatively simple design and can be tensioned to meet the weight of the sash in question. There are different size balances to meet the needs of differing height sashes.
They also eliminate the need for weight pockets and can be installed in smaller rough openings and allow for larger window sizes.
The problem with them is that just like any delicate mechanical item they can rust, dent, bend or otherwise break rendering them unworkable and in a lot of cases they are not repairable unless you can salvage missing/broken parts from a similar balance.
How To Remove Spiral Balances
This style balance is held in place with a single screw at the top corner of the jamb and one or 2 screws on the bottom of the sash. Each sash requires 2 balances (one on each side) to support it properly.
Before removing the balance you have to know that it is under tension and when the screws are removed the balance will spin dramatically to remove the tension. Depending on the weight of the sash this tension may be significant so do be careful when removing them.
Step 1 Remove Top Screw
On the bottom sash remove the screw in the top corner of the jamb holding the tube in place. These screws are notoriously difficult to remove since they have been in place for decades with tons of caked on paint or corrosion. Follow the tips on my post 4 Guaranteed Tricks to Remove Stubborn Screws if you get stuck.
If the screws are so stubborn that they simply won’t move (which is often the case) I usually end up wedging a pry-bar behind the tube and giving them a few swift pops to pry the screw out. These screws are more like a spiral shank nail than anything so they come out easier than a typical screw would when pried out.
Step 2 Remove the Support Bracket
After the retaining screw at the top is removed there is only one other place that needs to be removed to get the balance off and that is the screws in the bracket underneath the sash.
For a top sash this is underneath the meeting rail on either side of the sash. For a bottom sash it is on the bottom rail that rests on the sill when closed.
There will be one or two screws holding the bracket in place depending on the style of balance. You don’t need to remove the bottom bracket in order to remove the sash from the jamb, but to do any work on the sash or balance you will have to remove it so it’s best done now.
Remember these balances are under tension and will spin like the dickens when the first screw is removed so be careful. Now, let’s look at repair and reinstallation.
How To Repair Spiral Balances
I keep a stock of these in my shop because you never know when you’re going to need spare parts and the parts are not simple to find always. A salvage yard is a good place to find replacements if you need them or you can try manufacturers like Caldwell who still make versions of this balance.
Fixing Bent Balances
Most of the repairs I do with spiral balances are to straighten out bent balances. This is technically easy, but can be painstaking work to get right. Spiral balances will not work properly with kinks or bends in the tube or the spiral so straightening them out is essential to good operation.
You can use any number of tools to work out the kinks but my favorite are a small hammer and some pliers. Bottom line: do whatever it takes to get a straight balance again.
The brackets at the bottom often rust away or break from abuse. They can be replaced if you can find some extra junker balances to scrounge parts from.
There is a single rivet holding the bracket on in most cases that should be punched out with an awl and then you can attach a replacement bracket or have a machine shop make one for you if you can’t find one to match.
Tune Up & Cleaning
The standard treatment I give all the balances we get in the shop is to strip all the paint off of them with a wire wheel or steel wool and then wipe the dirty old grease from the spirals with WD40 until everything is clean and working smoothly.
How To Install Spiral Balances
This is the part that can give some folks trouble. This is the smoothest way I have found to reinstall these. I’m not proclaiming that this is the best way or the industry standard (there isn’t one), but this is how I like to do it.
To start with, this whole thing can be done with just one person, but it helps a TON to have a helper to hold the sash in place while you work. If you don’t have a helper then you’ll need to cut a block of wood to prop under the sash while you work to hold it in place.
Also, the steps are the same for the top sash and bottom sash so I’ll just walk through them once and you can handle it from there.
Step 1 Set the Sash in Place
When you sash is ready to go back in and the jamb has the parting beads removed set the top sash in its track and let it rest on the sill. Test it to make sure it slides smoothly in the jamb all the way to the top and bottom with no trouble before doing anything else.
Before setting the bottom sash make sure the top sash is in place, working smoothly and the parting beads are all installed.
Step 2 Drop in the Balance
The next steps will all be repeated on both sides of the sash since there are two balances per sash. With the sash in place drop the balance, bracket end first down into the mortise on the side of the sash. It should slide all the way down to rest on the sill while you hold the top of the tube above the sash.
Step 3 Attach the Tube
Pull the tube all the way up to the top of the jamb letting the spiral fall down into the sash mortise. Keep the seam on the tube toward the jamb so it doesn’t show. Attach the tube with one 1 1/2″ wood screw. A pan head screw works best, but really any attractive screw will work since it will be visible.
There are two things you need to focus on here:
- Don’t tighten the screw too much that you dent or flatten the tube.
- It’s imperative that you keep the tube centered in the track so that the sash can move fully up and down without binding.
Step 4 Tension the Balance
With the tube securely attached at the top slide the sash up to the upper most position and hold it there while you tension.
Grasp the bracket as it should have fallen through the bottom of the mortise on the side of the sash and begin to spin it clockwise.
It will get shorter as you make the revolutions. Continue turning until the bracket is almost at the bottom of the tube and then pull it down about 6-8 inches and continue turning (adding tension) until it makes its way back to the tube again.
At this point you should have enough tension to support a standard sash. Without letting go of the bracket move on to the next step to attach it.
Step 5 Set Bracket & Attach
Some brackets have a little nub on the end that allows it to be lightly hammered into a small mortise on the bottom of the sash. This allows the bracket to stay in place while you get a 1″ wood screw to securely attach the bracket onto the bottom of the sash.
Some brackets may accept two screws and I prefer these so if there is any way to add a second screw, do it. The extra insurance is well worth it!
Once both balances are attache, test the sash, moving it all the way up and down in the jamb. Stop at various points and make sure that the tension is adequate to support the sash wherever it may need to rest along its track.
You can always remove the bracket and adjust the tension (add a little, remove a little) as needed. Once you figure out the tension needed for the first window the rest will be very similar if they’re the same size.
Once both sashes are in put the stops back on and you’re ready for action. If you have questions about some of the other elements of removing a sash that I just touched on briefly like removing stops and parting bead, dealing with lead paint, etc. feel free to check out my resource page How To: Repair Old Wood Windows for a variety of posts on the different elements of a wood window and how to work with them.
There you have it! If you have any comments on your experiences with spiral or tube balances or have some suggestions on how it can be done smoother or tips for working with some of the many models of spiral balances please feel free to share those in the comments below as well.