Box Sash Window
Re-cording / Re-hanging
You will need:
- a hammer
- an old chisel, 25mm+ is preferable
- a screwdriver (most likely a flat bladed one)
- a Stanley knife
- a pair of pincers
- a nail punch
- a plane
- a mouse
- new sash-cord
- at least sixteen 25mm galvanised clout nails
- at least ten 38mm oval nails
- a small block of softwood (say 150mm of 50x25)
- new parting beads for the sides (there will be no need to disturb the top bead).
If you can, check that the axle-pulleys are not damaged or too badly worn to run smoothly, now is the time to replace them if they are.
Removing the sashes and weights
- With the knife, score through the paint where one of the staff beads meets the inside lining, this makes for a much neater job, especially if there are lots of layers of old paint.
- Using the chisel, start about halfway up and prise a staff bead away from the frame, taking care not to damage the arris (corner) of the inside lining. Work your way up and down until you can spring it out from where it is wedged in by the mitred joints top and bottom - watch out for the nails, they can be a bit vicious. Note which side it came from - they are not always exactly the same length.
- Remove the nails. The neatest way is to pull them right through with the pincers; if you knock them back through the staff bead they will probably force a flake of paint off or splinter the surface of the wood, leaving more making good to be done afterwards.
- If they are not already broken, cut through the sash-cords just above the bottom sash with the pincers, while holding them to prevent the weights from falling. Although it is harder to do, with pincers there is less likelihood of cutting oneself or damaging the woodwork than with a knife.
Lower the weights carefully, if they drop suddenly they can jam in the boxes making them difficult to remove, especially if the cords for the top sash have already snapped. Lift out the bottom sash.
- Cut through the paint either side of the parting beads using the knife and then prise them out of their grooves with the chisel. If need be use a packing to prevent damage to the pulley-stile. The beads will most likely break up as you do this, and even if they don't it is a good idea to replace them anyway. Make sure you get all the pieces out of the grooves.
- Remove the screws from the bottom of the pockets and, if necessary lever them out, bottom first.
- Remove the bottom sash-weights.
- Lower the top sash, cut the cords and lift it out
- Remove the top sash-weights. Keep them separate from the bottom ones, they may not weigh the same. .
- Remove the old cord and the nails from the grooves in the sides of both sashes and cut the cords off the weights.
- Now is a good time to have a bit of a clean-up - bit of a mucky job, isn't it?
Re-hanging the sashes
- Measure the distance from the bottom of each sash(including the horn in the case of the top sash) to the bottom of the sash-cord groove and make a mark on the pulley-stiles at this height above the cill.
- Tie the end of the mouse string to the new sash-cord and, in the sequence shown in the diagram, thread it into the box section over each axle-pulley and out through the pocket, pulling the cord through.
- Remove the mouse from the end of the sash-cord and fasten it to one of the bottom sash's weights using a bowline and pull the weight right up to the top. Nail through the cord into the pulley-stile close to the pulley to stop the weight dropping (nail it where it won't show once the staff-bead has been replaced). Now you can cut the cord to the length you marked on the pulley-stile.
Repeat with the other weights (for the top sash's weights you can nail into the parting bead groove, so it won't show when the job is finished).
- Nail the cords from the outermost axle-pulleys into the cord-grooves of the top sash. Use at least four nails each side, for heavier sashes use more. Take care not to nail too close to the top of the sash as doing this will foul the axle-pulleys and prevent the sash from being fully raised.
- Remove the nails you put in to stop the weights from dropping insert the sash into the frame and test that it runs smoothly.
- Measure and cut the parting beads parting beads to length, then with the plane just take the arisses (corners) off to ease fitting them into the grooves. Line the bead up in the groove and starting at one end (I find it best to start at the top, tight up against the top bead) and using the block of softwood to protect the bead, hammer it into the groove.
The parting beads are meant to be a tight fit, there should be no need to use nails; friction and paint will hold them in, so if they are too tight plane the bare minimum off to get a fit.
- Check that the top sash still runs OK.
- Fix the sash-cords to the bottom sash, again, don't nail too close to the top, then remove the temporary nails, insert the sash in the frame and test that it runs OK.
- Replace the staff beads, making sure you don't mix them up. Locate one end first and the other, bowing it out in the centre if necessary to get it in place. Using a spacer, such as a 1p coin, to ensure a small gap between the sash and the bead, nail the staff bead to the frame (not the sash!). Starting at the centre, nail approximately every 300mm (12"); if the staff beads are a good fit, you won't need to nail closer to the ends than around 200mm (if you nail any closer it gets very difficult to remove the beads again if the need should arise)
- Check that the bottom sash still runs ok. If it does, punch the nail heads just below the surface of the staff beads, and you've finished! Go and have a cup of tea or go to the pub.