My wife and I purchased our first house in August. One of the minor problems we noticed when we moved in was a broken slat in the blinds. We weren't too concerned with it because it had been hot glued by the previous owner and seemed to be working just fine. After a few weeks of being here the glue wore out. We spent a few weeks balancing it on the strings to make it appear closed, but it would always fall apart a few times a day. I had never thought about blinds as being something repairable, but realized something such as this shouldn't be trashed based on a single broken slat.
I did a search on Instructables and found many different things for blinds but none that involved repairing the broken slats. I found some instructions online but none with pictures. The fix is very simple and the pictures may not be necessary, but I know I would've gone into it with more confidence than I had.
Step 1: Identify the Problem and Intended Solution
My problem is obvious. The slat is broken right in the center. Fortunately the blinds are too long for the window and there are a few extra at the bottom. The plan is to remove the broken slat and replace it from one on the bottom.
Step 2: Find and Remove the Plugs
On the bottom of every set of blinds are at least 2 plugs holding and covering the lift strings. These are easily removed with a flat-head screw driver. You can then pull the lift string through the hole and either untie or cut off the knot. If you're removing a slat you will have plenty of extra string and can afford to cut the knot off as I did.
Step 3: Remove the Lift String
Once you have the knots removed from the lift string you can begin removing it. You only need to go as far as the slat you need to remove. In my case this is the broken slat; however, if you're just adjusting the blinds for a better window fit you will only remove the necessary bottom slats.
Step 4: Replace the Broken Slat.
Now you will put the replacement slat in place of the broken one. You will also move the base of the blinds up by one space so there are no gaps when fully extended.
Step 5: Rethread the Lift String
Check how the lift string is threaded and proceed to follow the same course with it through the slats and bottom.
(It was at this point that I realized this would've been a little easier if I had left the blinds open.)
Step 6: Thread the Base.
You can use tweezers or other means to push the string through the base. You will not see this once done so it doesn't matter how it looks. For 2 out of 3 I was able to trim the frayed string and slip it through, I had to use finishing nail to push the 3rd through. Tie each one off as close to the the same length as possible.
Step 7: Replace the Plugs
Now you will replace the 3 plugs removed at the beginning. Make sure these go over the rungs of the other string securing it in place.
Step 8: Finishing Up
Trim the excess string from the bottom and return the blinds to their original place.
alexc251 made it!