<PAGE>
 
                                                                  CONFORMED COPY

                                                                    Exhibit 10.6


                    AMENDMENT NO. 2, WAIVER AND AGREEMENT, dated as of February
               19, 1999 (this "Amendment"), to the Credit Agreement dated as of
               December 11, 1997 (the "Original Credit Agreement"), as amended
               by Amendment No. 1, Waiver and Agreement dated as of June 30,
               1998 ("Amendment No. 1", and together with the Original Credit
               Agreement, the "Credit Agreement"), among RBX CORPORATION, a
               Delaware corporation (the "Borrower"), the Lenders (as defined in
               the preamble to the Credit Agreement), THE CHASE MANHATTAN BANK,
               a New York banking corporation, as agent (in such capacity, the
               "Agent") for the Lenders and as the issuing bank (in such
               capacity, the "Issuing Bank").

          A. The Lenders and the Issuing Bank have extended, and have agreed to
extend, credit to the Borrower, in each case pursuant to the terms and subject
to the conditions set forth in the Credit Agreement.

          B. The Borrower has requested that the Lenders and the Agent grant a
limited waiver of compliance by the Borrower with the provisions of Sections
8.1(a) and (b) of the Credit Agreement, and the Agent and the Lenders are
willing to grant such limited waiver, on the terms and subject to the conditions
set forth herein.

          C. The Borrower has requested that the Lenders and the Agent amend the
Credit Agreement as provided herein, and the Agent and the Lenders are willing
to so amend the Credit Agreement, on the terms and subject to the conditions set
forth herein.

          D. Capitalized terms used but not defined herein shall have the
meanings assigned to them in the Credit Agreement.

          Accordingly, in consideration of the mutual agreements herein
contained and other good and valuable consideration, the sufficiency and receipt
of which are hereby acknowledged, the parties hereto agree as follows:

          SECTION 1. Waiver. The Lenders hereby waive compliance by the Borrower
with the provisions of Sections 8.1(a) and (b) of the Credit Agreement for the
fiscal quarters ending on March 31, 1999, June 30, 1999, September 30, 1999 and
December 31, 1999.

          SECTION 2. Amendments. (a) Section 1.1 (Defined Terms) of the Credit
Agreement is hereby amended by inserting after the definition for "Acquired
Entity" the following definition:

          "'Adjustment Rate':  if at any time (a) the Borrower, a Responsible
          Officer of the Borrower and the independent certified public
          accountants shall deliver the financial statements and certificates
          required by Sections 7.1 and 7.2 by the date specified in such
          Sections for such delivery and (b) such financial statements and
          certificates indicate that for the period of twelve consecutive months
          ending on the last day of the most recently ended fiscal quarter, the
          Consolidated Interest Expense Ratio is equal to or greater than 1.4 to
          1:00 and the Leverage Ratio is equal to or less than 6.5 to 1:00, then
          two business days after receipt by the Agent of such financial
          statements and certificates, the interest rates for the Eurodollar
          Loan and the ABR Loan and the letter of credit commission will be
          adjusted."

          (b) Section 3.3 (Fees, Commissions and Other Charges) of the Credit
Agreement is hereby amended by replacing the rate "2.50%" in the fifth line of
paragraph (b), with the rate "3.50%". Section 3.3 of the Credit Agreement is
further amended by inserting the following words at the end of the penultimate
sentence in paragraph (b):
<PAGE>
 
         ";provided that such rate will be equal to 3.00% per annum calculated
          on the basis of a 360 day year, on the aggregate amount available to
          be drawn under such Letter of Credit on the date on which such
          commission is calculated if the conditions for applying the Adjustment
          Rate are satisfied."

          (c) Section 4.1 (Interest Rates and Payment Dates) of the Credit
Agreement is hereby amended by (i) replacing the rate "2.50%" in the last line
of paragraph (a), with the rate "3.50%" and (ii) inserting the following words
at the end of the last sentence in paragraph (a):

         ";provided that such rate will be equal to the Eurodollar Rate
          determined for such date plus 3.00% if the conditions for applying the
          Adjustment Rate are satisfied."

Section 4.1 of the Credit Agreement is further amended by (i) replacing the rate
"1.50%" in the last line of paragraph (b), with the rate "2.50% and (ii)
inserting the following words at the end of the last sentence in paragraph (b):

         ";provided that such rate will be equal to the ABR for such date plus
          2.00% if the conditions for applying the Adjustment Rate are
          satisfied."

          (d) Section 8.1 (Financial Condition Covenants) of the Credit
Agreement is hereby amended by restating the table in paragraph (c) in its
entirety as follows:

<TABLE>
<CAPTION>
 
                   "Date                     Consolidated EBITDA
                ------------------           -------------------
                <S>                          <C>
                September 30, 1998               $ 11,000,000
                December 31, 1998                $ 18,500,000
                March 31, 1999                   $ 18,500,000
                June 30, 1999                    $ 19,000,000
                September 30, 1999               $ 20,000,000
                December 31, 1999                $ 21,000,000"
</TABLE>


          (e)  Section 8.8 (Limitation on Capital Expenditures) of the Credit
Agreement is hereby amended by restating the table in its entirety as follows:

<TABLE>
<CAPTION>
                "Fiscal Year                          Amount
                 -----------                       ------------
                <S>                                <C>                 
                    1998                           $ 13,000,000
                    1999                           $ 12,000,000
                    2000                           $ 10,000,000
                    2001                           $ 10,000,000
                    2002                           $ 10,000,000"
</TABLE>

In addition, Section 8.8 of the Credit Agreement is further amended by adding
the following at the end thereof:

         ";provided that for the fiscal year ending 1999, Capital Expenditures
          may not be greater than $12,000,000."

          SECTION 3.  Representations and Warranties.  To induce the other
parties hereto to enter into this Amendment, the Borrower represents and
warrants to the Agent, the Issuing Bank and each of the Lenders that:

          (a)  This Amendment has been duly authorized, executed and delivered
     by it and constitutes its legal, valid and binding obligation, enforceable
     in accordance with its terms except as such enforceability may be limited
     by bankruptcy, insolvency, reorganization,
<PAGE>
 
          moratorium or other similar laws affecting creditors' rights generally
     and by general principles of equity (regardless of whether such
     enforceability is considered in a proceeding at law or in equity).

          (b) Before and after giving effect to this Amendment, the
     representations and warranties set forth in Section 5 of the Credit
     Agreement are true and correct in all material respects on and as of the
     date hereof with the same effect as though made on and as of the date
     hereof, except to the extent such representations and warranties expressly
     relate to an earlier date.

          (c) Before and after giving effect to this Amendment, no Default or
     Event of Default has occurred and is continuing.

          SECTION 4. Fees. In consideration of the agreements of the Lenders
contained in Sections 1 through 3 of this Amendment, the Borrower agrees to pay
to the Agent, for the account of each Lender that delivers an executed
counterpart of this Amendment prior to 5:00 p.m., New York City time, on
February 19, 1999, an amendment fee (an "Amendment Fee") in an amount equal to
$50,000 to be shared pro rata between the Lenders.

          SECTION 5. Conditions to Effectiveness. This Amendment shall become
effective as of the date first above written (the "Effective Date") when (a) the
Agent shall have received counterparts of this Amendment that, when taken
together, bear the signatures of the Borrower and the Lenders and (b) the Agent
shall have received the Amendment Fee. Without limiting the foregoing, Section 2
of this Amendment shall apply to all Loans and Letters of Credit outstanding on
or after the Effective Date from and including the Effective Date.

          SECTION 6. Effect of Amendment. Except as expressly set forth herein,
this Amendment shall not by implication or otherwise limit, impair, constitute a
waiver of, or otherwise affect the rights and remedies of the Lenders, the Agent
or the Borrower under the Credit Agreement or any other Loan Document, and shall
not alter, modify, amend or in any way affect any of the terms, conditions,
obligations, covenants or agreements contained in the Credit Agreement or any
other Loan Document, all of which are ratified and affirmed in all respects and
shall continue in full force and effect. Nothing herein shall be deemed to
entitle the Borrower to a consent to, or a waiver, amendment, modification or
other change of, any of the terms, conditions, obligations, covenants or
agreements contained in the Credit Agreement or any other Loan Document in
similar or different circumstances. After the date hereof, any reference to the
Credit Agreement shall mean the Credit Agreement as modified hereby. This
Amendment shall constitute a "Loan Document" for all purposes of the Credit
Agreement and the other Loan Documents.

          SECTION 7. Applicable Law. THIS AMENDMENT SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

          SECTION 8. Counterparts. This Amendment may be executed in
counterparts (and by different parties hereto on different counterparts), each
of which shall constitute an original but all of which when taken together shall
constitute a single contract. Delivery of an executed signature page to this
Amendment by facsimile transmission shall be effective as delivery of a manually
signed counterpart of this Amendment.

          SECTION 9. Expenses. The Borrower agrees to reimburse the Agent for
its out-of-pocket expenses in connection with this Amendment, including the
reasonable fees, charges and disbursements of Cravath, Swaine & Moore, counsel
for the Agent.

          SECTION 10.  Notices.  All notices shall be given in accordance with
the provisions of Section 11.2 of the Credit Agreement.
<PAGE>
 
          SECTION 11. Headings. The headings of this Amendment are for purposes
of reference only and shall not limit or otherwise affect the meaning hereof.

          IN WITNESS WHEREOF, the parties hereto have caused this Amendment to
be duly executed by their respective authorized officers as of the day and year
first above written.


                              RBX CORPORATION,

                                  by
                                     /s/ John Cantlin
                                    -----------------
                                    Name:  John Cantlin
                                    Title:   Senior Vice President-CFO


                              THE CHASE MANHATTAN BANK, individually and as
                              Agent and Issuing Bank,

                                  by
                                     /s/ William J. Caggiano
                                    ------------------------
                                    Name:  William J. Caggiano
                                    Title:    Managing Director


                              BANKBOSTON, N.A.,

                                  by
                                     /s/ Michael J. McDermott
                                    -------------------------
                                    Name:  Michael J. McDermott
                                    Title:    Director