Repairing a too-deep slot in a Nut

 
What can be done if  a slot in the nut is cut too deep ? This may happen it the attempt is made to lower the action by working over the slots in the nut. And that's what happened to me: Two or three additional strokes done impatiently and the damage was done. The slot of the low e string almost approaches fretboard  level. The string buzzes any time it is played without being fretted. What can be done now ?

One opportunity would be to make a new nut (and by the way switch to bone). The other method I heard of would consist of filling the slot with a mixture of instant glue and baking soda. After that the slot can be cut new. That's what I did and here's the pictured story how it worked.
The Corpus delicti: The E-string slot is way too low, almost fretboard level.The low e-string buzzes like hell if played unfretted. Step #1: Reducing string tension and putting the string aside.
The tools used: Soda and instant glue as filling material, nut file, used razor blade, the file of my trusty Leatherman tool and adhesive tape.
Then I closed both ends of the slot using adhesive tape. The liquid to be filled in should not be allowed to pour out of the slot.

Then I cut back the tape using the razor blade.

After that I dripped two trops of instant glue into the slot and instantly threw a lot of soda on it.After five minutes I took off the adhesive tape. The result: No more e-string-slot  in the nut any more. There is an edge of some surplus material to be seen on the nut's upper surface.

Now the edge has to be removed. This I did utilizing the file of my old Leatherman tool. I painstakingly took care, not to mar or scratch any part of the neck or headplate.

The result: No more groove or slot for the low e string.

Now I had to saw a new e-string slot. With the thickest of my nut sawblades this was a quick task. The compound material of instant glue and soda is quite brittle. While sawing I avoided any contact of sawblade and headplate. Additionaly I moved the blade always keeping the angle to be seen on the picture below. The angle of the blade forms the same angle with the string's sides both left and right of the nut.

After having reached the proper depth I cleaned headplate and fretboard. The compound material seems to stand the string pressure well. Now the guitar is set up right, no more string buzz any longer.