THE BANK OF NEW YORK
285 Main Mall, Poughkeepsie, New York 12601


June 14, 1996


Sono-Tek Corporation
Building #3
2012 Route 9W
Milton, New York 12547

Gentlemen:

We refer to the  promissory  note,  dated  October  23,  1991,  made by Sono-Tek
Corporation (the "Company") to the order of The Bank of New York (the "Bank") in
the original  principal  amount of $300,000 as amended by the letter  agreement,
dated October 5, 1993 (the "Letter Agreement"), between the Bank and the Company
(as so  amended,  the  "Note").  As of the  date  hereof  the  principal  amount
outstanding under the Note is $175,915.28.

The Note is hereby  modified by amending the Letter  Agreement  as follows:  the
phrase "1st of November  1996" in clause (a) of the Letter  Agreement is deleted
and in its place the phrase "1st of August 1998" is inserted.

All other terms and provisions of the Note (including,  without limitation,  the
other terms and provisions of the Letter  Agreement)  shall remain in full force
and effect.

Please  indicate  your  agreement  to the  foregoing  by  executing  this letter
agreement on the line  provided  below and returning an original copy thereof to
the Bank.

Very truly yours,

/s/ Dianne F. Davis

Dianne F. Davis
Assistant Vice President
Commercial Lending

Accepted and Agreed to:

SONO-TEK CORPORATION

By:   /s/ J. D. Urquhart
      Name: J. Duncan Urquhart
      Title: Controller and Treasurer