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                                                                   EXHIBIT 10.51

                                 FIRST AMENDMENT
                                       TO
                   AMENDED AND RESTATED REVOLVING CREDIT NOTE

     This Amendment is entered into as of December 16, 2003 by and between CHASE
CORPORATION, a Massachusetts corporation (the "BORROWER"), and FLEET NATIONAL
BANK, a national banking association (the 'Bank").

     WHEREAS, the Bank and the Borrower entered into a certain loan arrangement
on October 31, 2001, as amended, which is evidenced, in part, by a certain
Amended and Restated Revolving Credit Note dated October 31, 2001 (the
"REVOLVING NOTE") made by the Borrower payable to the order of the Bank in the
principal amount of $6,000,000 and a certain First Amended and Restated Loan
Agreement dated October 31, 2001, as amended, between the Borrower and the Bank
(the "LOAN AGREEMENT"); and

     WHEREAS, the Bank and the Borrower have on this date amended the Loan
Agreement pursuant to a certain Fifth Amendment to First Amended and Restated
Loan Agreement; and

     WHEREAS, the Borrower and the Bank are desirous of amending the Revolving
Note in the manner set forth below;

     NOW THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the Borrower and the Bank agree as
follows:

     1.   Effective as of the date first written above, the $6,000,000 principal
amount of the Revolving Note reflected in the upper left hand corner thereof
shall be deemed amended to read "$7,000,000".

     2.   The Revolving Note is hereby further amended, effective as of the date
first written above, by deleting the first paragraph thereof in its entirety and
replacing it with the following:

          "FOR VALUE RECEIVED, CHASE CORPORATION, a Massachusetts corporation
     (the "Borrower"), hereby promises to pay to the order of FLEET NATIONAL
     BANK (the "Bank") the principal amount of Seven Million Dollars
     ($7,000,000.00) or such portion thereof as may be advanced by the Bank
     pursuant to Section 1.2 of that First Amended and Restated Loan Agreement
     dated as of October 31, 2001 between the Bank and the Borrower, as amended,
     restated, supplemented, replaced or otherwise modified from time to time
     (the "Loan Agreement") and remains outstanding from time to time hereunder
     ("Principal"), with interest, at the rate hereinafter set forth, on the
     daily balance of all unpaid Principal, from the date hereof until payment
     in full of all Principal and interest hereunder. Terms defined in the Loan
     Agreement are used herein with the meanings so defined."

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     3.   Except as specifically provided herein, all terms and conditions of
the Revolving Note shall remain in full force and effect and are hereby ratified
and confirmed. This Amendment constitutes an amendment to and modification of
the Revolving Note and not a refinancing thereof. On and after the date hereof,
each reference in the Revolving Note to "this Note", "hereunder", "hereof' or
words of like import referring to the Revolving Note, shall mean and be a
reference to the Revolving Note as amended by this Amendment, and each reference
in any loan documents between the Borrower and the Bank to the Revolving Note,
"thereunder", "thereof" or words of like import referring to the Revolving Note
shall mean a reference to the Revolving Note as amended by this Amendment.

     4.   This Amendment may be executed by the parties hereto in several
counterparts hereof and by the different parties hereto on separate counterparts
hereof, all of which counterparts shall together constitute one and the same
agreement

     This Amendment shall take effect as a sealed instrument under the laws of
the Commonwealth of Massachusetts as of the date first written above.

                                          CHASE CORPORATION

                                          /S/  EVERETT CHADWICK
                                          ------------------------
                                          Title: TREASURER & CFO

                                          FLEET NATIONAL BANK

                                          By: /s/ [ILLEGIBLE]
                                             -----------------------<Page>
                                                                   EXHIBIT 10.56

                                    TERM NOTE

     DEFINED TERMS. As used in this Term Note (the 'Note' ), the following terms
     shall have the following mom:

     1.1  BORROWER:        Chase Corporation
                           a Massachusetts corporation
                           26 Summer Street
                           Bridgewater, Massachusetts 02324

     1.2  LENDER:          Citizens Bank of Massachusetts
                           28 State Street Boston, MA
                           02109

     1.3  LOAN AMOUNT:       $2,300,000.00

     1.4  INTEREST RATE:           See Section 3 BELOW.

     1.5  MATURITY DATE:   JANUARY 8, 2008

     1.6  LOAN AGREEMENT: a certain Term Loan Agreement of even date herewith by
     and between Borrower and Lender.

     1.7  LOAN, LOAN DOCUMENTS AND EVENT OF DEFAULT shall have the same meanings
          as in the Loan Agreement. The Loan Documents are incorporated herein
          by reference. All capitalized terms used herein and not otherwise
          defined herein SHALL have the meanings as SET FORTH IN the Loan
          Agreement.

     1.8  PREPAYMENT PERIOD;    At any time during the term of the Loan.

2.   DEBT: For value received, Borrower hereby promises to pay to the order of
     Lender the Loan Amount, together with interest on all unpaid balances from
     the date of such advances made under this Note at the interest rate set
     forth in this Note, together with all other amounts due hereunder or under
     the Loan Documents.

3.   INTEREST: Interest on all amounts advanced under this Note SHALL accrue
     interest at either (t) a floating per ANNUM rate of interest equal to the
     Prime Rate (as announced by Lender from TIME TO TIME), OR (II) AN
     adjustable per annum rate equal to the LIBPR Rate plus the Applicable
     Margin (as such terms are defined in Rider A entitled "Provisions for
     Citizens LIBOR Rate LOANS" attached hereto and made a part hereof).
     Borrower may elect either interest rate option by written notice to Lender
     upon the date of this Note and thereafter upon any interest payment date
     during the term of this Note. The interest rate selected by Borrower shall
     continue during the term of the

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     Note until Lender receives written notice from Borrower of a requested
     change. In the absence of any written election by Borrower, this Note shall
     accrue interest at the Prime Rate option as set forth above. Interest shall
     be calculated on the basis of the number of actual clays elapsed and a
     360-day year.

     PAYMENTS: Borrower shall make payments of interest on the amounts advanced
     by Lender under this Note monthly in arrears while any part of the
     indebtedness evidenced hereby is unpaid commencing on the date which is one
     (1) month after the date of this Agreement (the "First Payment Date") and
     thereafter on each monthly anniversary of the First Payment Date. In
     addition to accrued interest, Borrower shall make quarterly, payments of
     principal in the amount of $143,750,00 on each quarterly anniversary of the
     First Payment Date during the term of this Note . Upon Maturity Date,
     Borrower shall pay to Lender the entire then unpaid balance of principal
     and interest under this Note.

     Any payments on this Note, whether such payment is of a regular installment
     or represents a prepayment (if permitted hereunder), shall be made in coin
     and currency of the United States of America which is legal tender for the
     payment of public and private debts, in immediately available funds, to
     Lender at Lender's address set forth or at such other address as Lender may
     from time to time designate in writing.

5.   DEFAULT INTEREST: If any payment due hereunder or UNDER ANY OF the Loan
     Documents is not paid within ten (10) days when due, then and in such
     event, Borrower shall, in addition to any other payment due hereunder, pay
     interest thereon from and after the date on which such payment first
     becomes due at an annual interest rate equal to the Interest LATE plus four
     percent (4%) and such interest shall be due and payable, on demand, at such
     rate until the entire amount DUE IS paid to Lender, whether or not any
     action shall have been taken or proceeding commenced to recover the same.
     Nothing in this Section 5 or in any other provision of this Note shall
     CONSTITUTE an extension of the time of payment of the indebtedness
     hereunder,

6.   DELINQUENCY CHARGES: If Borrower fails to pay any amount of interest on
     this Note for ten (10) days after such payment becomes due, Lender may, at
     its option, whether immediately or at the time of final payment of the
     amounts evidenced by this Note impose a delinquency or "late" charge equal
     to five percent (5%) of the amount of such past due payment notwithstanding
     the date on which such payment is actually paid in full. Borrower agrees
     that any such delinquency charges shall not be deemed to be additional
     interest or penalty, but SHALL be deemed to be liquidated damages because
     of the difficulty in computing the actual amount of damages in advance,

7.   COSTS AND EXPENSES UPON DEFAULT: After default, in addition to principal,
     interest and delinquency CHARGES, Lender SHALL be entitled to collect all
     costs of collection, including, but not limited to, reasonable attorneys,
     fees and expenses, incurred in connection WITH ANY OF LENDER'S collection
     efforts, WHETHER OR NOT suit on this Note is filed, and all such COSTS and
     expenses shall be payable on

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     demand.

8.   APPLICATION OF PAYMENTS: Unless an Event of Default has occurred, all
     payments hereunder shall be applied fist to delinquency charges, costs of
     collection and enforcement and other similar amounts due, if any, under
     this Note and under the other Loan Documents, then to interest which is due
     and payable under this Note and the remainder, if any, to principal due and
     payable under this Note. If an Event of Default has occurred, such payments
     may be applied to sums due under this Note or under the other Loan
     Documents in any order and combination that Lender may, in its sole and
     absolute discretion, determine.

9.   PERMITTED PREPAYMENT: Borrower shall have the right to prepay the Loan in
     whole or in part, at any time during the Prepayment Period.

10.  COSTS; ILLEGALITY OF LOAN: In addition to principal, interest and
     delinquency charges, Borrower shall pay all costs and expenses, including,
     without linitat7on, reasonable attorneys' fees and all reasonable expenses
     and disbursements of counsel, in connection with the protection,
     realization or enforcement of any of Lender's rights AGAINST Borrower or
     any other liabilities of Borrower to Lender (whether or not suit or
     foreclosure is instituted by or against Lender).

     Borrower hereby agrees to pay to Lender on demand (i) all costs and
     expenses of Lender in commotion with, and any stamp or other taxes or
     charges (including filing fees) payable with respect to, this Note and the
     enforcement hereof; and (u) any amount necessary to compensate it for (a)
     any losses or costs (including funding costs) sustained by it as a
     consequence of any default by Borrower hereunder; and (b) any increased
     costs Lender may sustain in maintaining the borrowing evidenced hereby due
     to the introduction of or any change in, law or applicable regulations
     (including the interpretation thereof) or due to the compliance by Lender
     with any guideline OR request from any central bank or governmental
     authority. In addition if it shall become unlawful, or any central bank or
     other governmental authority shall assert it to be unlawful, for Lender (or
     any bank which is directly or indirectly funding Lender with respect to the
     Loan) to maintain the borrowing evidenced hereby, Borrower agrees to prepay
     this Note in full together with accrued interest and other amounts payable
     hereunder on demand.

11.  WAIVERS: THE BORROWER HEREBY IRREVOCABLY WAIVES ITS RIGHTS TO NOTICE AND
     HEARING TO THE EXTENT PERMITTED BY LAW OF ANY STATE OR FEDERAL LAW WITH
     RESPECT TO ANY PREJUDGMENT REMEDY WHICH LENDER MAY DESIRE TO USE, and,
     further, irrevocably waives presentment for payment, demand, notice of
     nonpayment, notice of intention to accelerate the maturity of this Note,
     diligence in collection, commencement of suit

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     AGAINST any obligor, notice of protest, and protest of this NOTE and all
     other notices in connection with the delivery, acceptance, performance,
     default or enforcement of the payment of this Note, before or after the
     maturity of this Note, with or without notice to Borrower, and agrees that
     Borrower's liability SHALL not be in any manner affected by any indulgence,
     extension of time, renewal, waiver or modification tented or consented to
     by Lender. Borrower consents to any and all extensions of time, renewals,
     waivers or modifications that may be granted by Lender with respect to the
     payment or other provisions of this Note. Any delay on the part of Lender
     in exercising any right under this Note shall not operate as a waiver of
     any such right, and any waiver granted or consented to on one occasion
     shall not operate as a waiver in the event of any subsequent default.

12,  NO USURY: Lender and Borrower intend to comply at all times with applicable
     usury laws, If at any time such laws would ever render usurious any amounts
     called for under this Note or the other Loan Documents, then it is
     Borrowers and Lender's express intention that Borrower shall not be
     required to pay interest on this Note at a rate in excess of the maximum
     lawful rate, that the provisions of this Section 12 shall control over all
     other provisions of this Note and the Loan Documents which may be in
     apparent conflict herewith, that such excess amount shall be credited to
     the principal balance of this Note (or, if this Note has been fully paid,
     refunded by Lender to Borrower), and the provisions hereof shall be
     reformed and the amounts thereafter collectible under this Note reduced,
     without the necessity of the execution of any further documents, so as to
     comply with the then applicable law, but so as to permit the recovery by
     Lender of the fullest amount otherwise called for under this Note. Any such
     crediting or refund shall not cure or waive any default by Borrower tinder
     this Note or the other Loan Documents. If at any time following any
     reduction in the interest rate payable by Borrower there remains unpaid any
     principal amount under this Note and the maximum interest rate allowed by
     applicable law is increased or eliminated, then the interest rate payable
     under this Note shall be readjusted, to the extent not prohibited by
     applicable law, so that the dollar amount of interest payable hereunder
     shall be equal to the dollar amount of interest which would have been paid
     by Borrower without giving effect to the reduction in interest resulting
     from compliance with applicable usury laws. Borrower agrees that in
     determining whether or not any interest payable under this Note or the
     other Loan Documents exceeds the highest rate allowed by law, any non
     principal payment (except payments specifically stated in this Note or in
     the other Loan Documents to be "interest"), including, without limitation,
     prepayment fees and delinquency charges, shall, to the maximum extent
     allowed by law, be an expense, fee or premium rather than interest. The
     term "applicable law", as used in this Note shall mean the laws of The
     Commonwealth of Massachusetts or the laws of the United States, whichever
     laws allow the greater rate of interest, as such laws now exist or may be
     changed or amended or come into effect in the future.

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13.  ACCELERATION AND OTHER REMEDIES: If

          (a)  Borrower fails to pay any sum within five (5) days of when due
     under this Note; or

          (b)  an "Event of Default", as said team is defined in the Loan
     Agreement or any other Loan Document, occurs;

     then, and in any such event Lender may, at its option, declare the e the
     unpaid balance of this Note together with interest accrued thereon, to be
     immediately due and payable and Lender may proceed to exercise any rights
     or remedies that it may have under this Note, the Loan Agreement, the other
     Loan Documents or such other rights and remedies which Lender may have at
     law, equity or otherwise.

14.  SUCCESSORS AND ASSIGNS: This Note shall be binding upon Borrower and upon
     its respective heirs, successors, assigns and representatives, and shall
     inure to the benefit of Lender and its successors, endorsees, and assigns.

15.  DEPOSITS: Any and all deposits or other sums at any time credited by or due
     from Lender to Borrower and any cash, securities, instruments, or other
     property of Borrower which now or hereafter are at any time in the
     possession or control of Lender, constitute additional security to Lender
     for the Liabilities of Borrower to Lender including, without limitation,
     the liability evidenced hereby, and may be applied or set off by Lender
     against such liabilities at any time from and after an Event of Default
     hereunder whether or not other collateral is available to Lender.

16.  COLLECTION: Any check, draft, money order or other instrument given in
     payment of all or any portion hereof may be accepted by Lender and handled
     by collection in the customary manner, but the same shall not constitute
     payment hereunder or diminish any rights of Lender except to the extent
     that actual cash proceeds of such instrument are unconditionally received
     by Lender and applied to this indebtedness in the manner elsewhere herein
     provided.

17.  AMENDMENTS: This Note may be changed or amended only by an agreement in
     writing signed by the party against whom enforcement is sought.

18.  GOVERNING LAW; SUBMISSION TO JURISDICTION: This Note is given to evidence
     debt for business or commercial purposes, is being delivered to Lender at
     one of its offices in The Commonwealth of Massachusetts and shall be
     governed by and construed under the laws of said Commonwealth. Borrower
     hereby submits to personal jurisdiction in said Commonwealth for the
     enforcement of Borrower's obligations

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     hereunder, under the Loan Agreement and under the other Loan Documents, and
     waives any and all personal rights under the law of any other state to
     object to jurisdiction within such Commonwealth for the purposes of
     litigation to enforce such obligations of Borrower. In the event such
     litigation is commenced, Borrower agrees that service of process may be
     made, and personal jurisdiction over Borrower obtained, by service of a
     copy of the summons, complaint and other pleadings required to commence
     such litigation upon Borrower at the address set forth in the preamble to
     this Note.

19.  CAPTIONS: All paragraph and subparagraph captions are for convenience of
     reference only and shall not affect the construction of any provision
     herein.

IN WITNESS WHEREOF, THIS NOTE HAS BEEN EXECUTED AND DELIVERED UNDER SEAL AS OF
THE
           8TH DAY OF JANUARY 2004.

                                                       CHASE CORPORATION

BY:  /s/ PETER R. CHASE, PRESIDENT
     -----------------------------

WITNESS
/s/ PAULA M. MYERS, WITNESS
---------------------------

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