The best time to replace the lift cord that raises and lowers a miniblind is when you first notice it's frayed—don't wait till it breaks. It's much easier to use the old cord to guide a new one (you temporarily splice them together) and pull it through the intricate pathway of ladder lines, slats and headbox hardware than to thread a new cord inch by inch by itself through the labyrinth.
Miniblind repair decisions should begin with the question, ”Is it easier to fix this or buy a new one?” If you’ve got a cheap vinyl miniblind that's not a custom size and color, throw it out. We chose to fix our more expensive faux-wood slat blind. This fix works on pleated shades as well. Finding replacement braided nylon lift cord of the right thickness is tricky; home centers don't carry it. Look in the Yellow Pages under ”Window Coverings, Repair and Cleaning.” Most places carry stock cord in white, beige and brown. For pleated shades, select lift cord that’s .9 mm thick; for vinyl miniblinds, 1.4 mm; for wood slat blinds, 1.8 mm. Cord is inexpensive. To figure how much cord you'll need, multiply the height of your extended blinds by 4 and add the width. (A blind 3 ft. wide and 5 ft. high would need about 23 linear feet of lift cord: 4 x 5 = 20; 20 + 3 = 23.)
Pull on the frayed lift cord until the slats are drawn together. Cut the cord at the fray and pull the discarded piece (with the knotted end) out through the bottom bar. Splice the new cord to the old by hot-gluing the tips together and rolling them up tightly in a 3-in. long strip of plastic electrical tape.
4 Rehang the shade and draw the new lift cord through the cord pathway. With one hand guiding the cord splice through the slats and headbox hardware, pull on the old lift cord. When the splice is clear of the headbox, draw the new lift cord to the bottom bar, undo the splice and attach any plastic pulls on the end of the new cord.
While the blind is still hung (Fig. A), make the task easier by studying, sketching or shooting digital photos of your blind's lift cord pathways before you begin the repair. Then take 45 minutes and follow the steps shown in Photos 1 – 3. Since the cord splice may not pass through the small hole in the bottom bar, make it above the bar. Then drop the loose end of the new lift cord through the hole in the bottom bar and tie a new knot (Fig. B). Keep your slats aligned in a straight vertical line by weaving the lift cord alternately in and out of the ladder rungs.Caution: Leave the ends of the two lift cords untied. Small children have accidentally hanged themselves on tied cords that formed a loop.
Figure B: Bottom Rail Detail
Feed the end of the new lift cord through the small hole in the bottom bar and tie a retaining knot. Make sure the bottom loop of the ladder goes around the bottom bar. Tuck the loose ladder strings and lift cord knot into the rail hole and reinstall the plastic plug.