Neumann UM57 - broken grille repair

[MS Vienna]

Hello,

some time ago the owner of a damaged Neumann/Gefell UM57 approached me, asking if I could repair his mic.
The grille had been ripped off and an unsuccessful repair attempt already performed. So I gave it a go and tried my best.

First I cleaned up the mess to get a good fresh metal surface. I then used solder paste to attach the grille to the base ring.  After finishing it seemed to be a good and stable solder joint and the mic was back in working order. That was already some years ago and it seems to hold up well.

I just stumbled across the pictures and thought I´d post it here.

Happy weekend!

 

[ln76d]

Great work!

Two questions
How did you cleaned up the mess?
What solder paste did you used?

 

[Moby]

Well done

 

[MS Vienna]

As far as I remember I used steel wool and sandpaper on the mesh, then put it in the ultrasonic cleaner, then etched away remaining oxides with acid.
I cleaned up the base ring on the lathe.  I was very careful to take off just as much material as necessary. I cut in way less than 0,1mm into the ring´s material for sure - just in case it looks alarming in the picture.

I used  soft-solder paste by Rothenberger.

 

[ln76d]

Thanks!

 

[MS Vienna]

While searching for SM204 pictures for another thread I came across these. Thought I just throw them in here.
Again not one of my UM57 but from an unlucky friend. Obviously it received a  sustantial bang and I was asked to bring it back in shape. Not too hard to do in this case.