When touching up the paint of Tefilin is it also acceptable to say “leshem kedushas tefillin”?
Answer:
Yes. Painting tefillin must be done lishmah, and therefore before beginning one must say “leshem kedushas tefillin”.
According to the Ashkenaz custom, not saying “leshem kedushas tefillin” constitutes a problem even on a bedieved level.
Best wishes.