THIRD NOTE AMENDMENT AGREEMENT


Reference is made to that certain  Convertible  Secured  Subordinated  Note (the
"Note") by and between  Sono-Tek  Corporation  ("Sono-Tek" or the "Company") and
(the  "Holder")  in the  principal   amount of $DOLLARS  made as of November 16,
1993, and the Note Amendment  Agreement made as of March 23, 1995 and the Second
Note Amendment Agreement made as of April 30, 1996.

Whereas the Company has not made several interest  payments to Holder which were
due on the dates and in the amounts shown in Attachment 1 hereto, and

Whereas the failure of the Company to make said  interest  payments on the dates
due constitutes an act of default in accordance with the terms of the Note, and

Whereas it is  unlikely  that the  Company  will be able to repay the  principal
amount of the Note in the amount  stated  above when such amount  becomes due on
August 15, 1997.

Now, therefore, the Company and the Holder hereby agree as follows:

1.      The total amount of past due  interest as shown on  Attachment I hereto,
        as well as interest due on the past due  interest,  shall be paid to the
        Holder by the  Company as soon as  practical  after the  signing of this
        Agreement.  Payment  shall be in the  form of  shares  of the  Company's
        Common Stock,  which number was  determined by dividing the total amount
        of past due interest and interest thereon by $0.40.

        These shares shall bear the  restrictive  legend set forth in Attachment
        II hereto.

2.      The Holder  agrees to waive the right of  default  and will not seek any
        remedies  against the Company  provided in the Note based on the failure
        of the  Company  to pay,  in a timely  fashion,  the  interest  payments
        described in Paragraph 1.

3.      The Holder agrees to  extend the  due date  of the  Note from August 15,
        1997 until August 15, 2000.

4.      The Company shall pay interest to the Holder for each of the  additional
        three years at a rate equal to 1% below the prime rate as  announced  by
        the Wall Street Journal on August 15, 1997,  August 15, 1998, and August
        15, 1999. Interest shall be payable quarterly in arrears on the 15th day
        of November, February, May, and August.

5.      From the date hereof until March 1, 1998, the Holder agrees to waive the
        right of default  and will not seek any  remedies  against  the  Company
        provided  in the Note based on the  failure of the  Company to pay, in a
        timely fashion, the interest payments due commencing on May 15, 1997 and
        continuing through February 15, 1998.

6.      Holder, by his  signature  hereto, agrees  to all of  the  provisions of
        Attachment II.



April 30, 1997
Sono-Tek Corporation


- ---------------                                           ----------------
James L. Kehoe                                                 NAME
Chief Executive Officer

                                       42