AMENDMENT NO. 1
                               TO CREDIT AGREEMENT


                                           As of June 30, 1999

         CHEMFAB  CORPORATION,   a  Delaware   corporation,   (the  "Borrower"),
BANKBOSTON,  N.A., a national banking association  ("BankBoston"),  THE GOVERNOR
AND COMPANY OF THE BANK OF IRELAND, a bank licensed under the Irish Central Bank
Acts,  1942 to 1989 (the "Bank of Ireland"),  and any other Lenders from time to
time party hereto,  and BankBoston as agent for the Lenders (the "Agent") hereby
agree as follows:

1. Reference to Credit Agreement;  Definitions.  Reference is made to the Credit
Agreement  dated as of  October 4,  1996,  as amended  and in effect on the date
hereof (the "Credit Agreement"), among the Borrower, BankBoston, Bank of Ireland
and the Agent.  The Credit Agreement as amended by this Amendment is referred to
herein as the "Amended  Credit  Agreement".  Terms defined in the Amended Credit
Agreement and not otherwise  defined herein are used herein with the meanings so
defined.

2. Amendments to the Credit  Agreement.  Subject to all the terms and conditions
hereof,  effective as of the date hereof, the Credit Agreement is hereby amended
as set forth herein.

         2.1. Amendment to Section 2. The definition of Revolver Conversion Date
in Section 2 is hereby amended to read in its entirety as follows:

         ""Revolver Conversion Date" means December 31, 1999."

         2.2. Amendment to Section 6.15. Section 6.15 of the Credit Agreement is
hereby amended to read in its entirety as follows:

                  "6.15.  Limit on Capital  Expenditures.  The  Borrower and its
         Subsidiaries will not make Capital Expenditures  exceeding  $10,000,000
         (excluding Permitted  Acquisitions pursuant to 6.9.6) in the Equivalent
         Amount of United  States Funds in the  aggregate in any calendar  year;
         provided,  however, that for the fiscal year of the Borrower ended June
         30,  1999,  the  Borrower  and  its   Subsidiaries   may  make  Capital
         Expenditures   not   exceeding    $10,500,000    (excluding   Permitted
         Acquisitions  pursuant  to  6.9.6) in the  Equivalent  Amount of United
         States Funds in the aggregate."

3. Conditions to Amendment. The effectiveness of this Amendment shall be subject
to the  satisfaction,  on or before the date hereof, of the conditions set forth
in this Section 3.

         3.1.  Payment  of  Fees.  The  Borrower  shall  have  paid the fees and
expenses of the Agent's  counsel,  Ropes & Gray, in  connection  with the Credit
Agreement and this

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Amendment.

         3.2.  General.  All legal and corporate  proceedings in connection with
the  transactions  contemplated  by this Amendment shall be satisfactory in form
and substance to the Agent,  and the Lenders  shall have received  copies of all
documents,  including  records of corporate  proceedings,  which the Lenders may
have  reasonably  requested  in  connection  therewith,   such  documents  where
appropriate to be certified by proper corporate or governmental authorities.

4. No Default. In order to induce the Lenders to enter into this Amendment,  and
to continue to extend credit to the Borrower under the Amended Credit Agreement,
the Borrower  represents  and warrants to the Lenders that no Default  under the
Credit  Agreement  now exists,  and after  giving  effect to this  Amendment  no
Default under the Amended Credit Agreement shall exist.

5.  Miscellaneous.  Except  to  the  extent  specifically  amended  hereby,  the
provisions of the Credit Agreement shall remain  unmodified,  and subject to the
conditions  contained in this Amendment,  the Amended Credit Agreement is hereby
confirmed as being in full force and effect.

         This  Amendment  may be  executed in any number of  counterparts  which
together shall constitute one instrument,  shall be governed by and construed in
accordance with the laws of The Commonwealth of Massachusetts, without regard to
the conflict of laws rules of any jurisdictions, and shall bind and inure to the
benefit  of the  parties  hereto and their  respective  successors  and  assigns
pursuant to Section 11 of the Amended Credit Agreement.

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         Each of the  undersigned  has caused this  Amendment to be executed and
delivered by its duly  authorized  officer as an agreement  under seal as of the
date first above written.

                                         CHEMFAB CORPORATION


                                         By:  /s/ Moosa E. Moosa
                                         Name:  Moosa E. Moosa
                                         Title:    Vice President-Finance & CFO

                                         700 Daniel Webster Highway
                                         Merrimack, NH  03054
                                         Attention:  Moosa E. Moosa
                                         Telecopy:  (603) 424-9028

                                         BANKBOSTON, N.A.
                                         f/k/a The First National Bank of Boston


                                         By:  /s/ Patricia K. Conry
                                         Name:  Patricia K. Conry
                                         Title:    Director

                                         100 Federal Street
                                         Boston, Massachusetts 02110
                                         Attention:  Patricia K. Conry
                                         Telecopy:  617-434-8102

                                         THE GOVERNOR AND COMPANY OF THE
                                         BANK OF IRELAND

                                         By:   /s/ Sheila Neary
                                         Name:   Sheila Neary
                                         Title:     Secretary

                                         By:  /s/ Josephine Doherty
                                         Name:  Josephine Doherty
                                         Title:    Bank Assistant

                                         Corporate Banking
                                         Lower Baggott Street, B2
                                         Dublin 2, Ireland
                                         Attention:  Fran Collins
                                         Telecopy:  011-35-3-1604-4105
[Chemfab Amendment No. 1]

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