AMENDATORY AGREEMENT

           WHEREAS, Sundial International Fund Limited ("Sundial") and
 Ultra Pacific Holdings S.A. ("Ultra"), on the one hand, and Metalclad
 Corporation ("MTLC"), on the other hand, heretofore entered into a
 Purchase Agreement dated as of the 31st day of December, 1997 as amended
 by Section 2.7.3 of that certain Purchase Agreement by and between Ultra
 and MTLC dated as of the 18th day of June, 1998, and as further amended by
 that certain Offer from Metalclad to Ultra, Sundial and others dated
 February 23, 1999 as subsequently amended by the substitution of various
 schedules thereto as accepted by Ultra, sundial and such others (said
 Offer from Metalclad as so amended and accepted being sometimes referred
 to as the "Offer", and said Purchase Agreement dated as of the 31st day of
 December, 1997 as so amended by the Purchase Agreement dated as of June
 18, 1998 and by the Offer being hereinafter sometimes referred to as the
 "Original Purchase Agreement".

           WHEREAS, capitalized terms used herein and not defined herein
 are used herein as defined in the Original Purchase Agreement, the Pledge
 Agreement or the Registration Rights Agreement, as the same may be
 modified by this Agreement;

           WHEREAS, the original Purchase Price of the Notes was $1,500,00
 ("Original Purchase Price"), $1,000,000 being attributable to the Sundial
 Note and $500,000 being attributable to the Ultra Note;

           WHEREAS, the parties hereto wish to increase the Purchase Price
 of the Notes (i) by capitalizing interest accrued through and including
 July 30, 1999; and (ii) by the making by Sundial and Ultra of an
 additional loan to MTLC in the amount of $250,000.

           WHEREAS, the original Principal Amount of the Notes, being the
 amount due at maturity of the Notes on December 31, 2002, the Notes being
 Zero Coupon Notes, was $2,200,000 ("Former Principal Amount"), of which
 $1,466,666.67 was attributable to the Sundial Note ("Sundial Former
 Principal"), and $783,333.33 was attributable to the Ultra note ("Ultra
 Former Principal Amount");

           WHEREAS, the parties have agreed effective July 30 to increase
 the imputed interest rate on the Notes to 12% and as a consequence thereof
 and of the transactions contemplated by the second preceding recital
 hereof, the Former Principal Amounts of the Notes will be increased to
 the "New Principal Amounts" (defined Below) and the definition of
 Discounted Present Value will be modified accordingly;

           WHEREAS, it has been previously agreed that the Conversion Rate
 would be changed to the lesser of (i) 70% of the Market Price of the MTLC
 Common Stock or (ii) 25 cents per share of the Common Stock of MTLC, said
 Common Stock upon conversion to be paid for by cancellation of such
 portion of the Original Purchase Price of the Notes being converted equal
 to the number of shares being acquired multiplied by the lesser of (i) or
 (ii), and the concurrent cancellation of all interest accrued attributable
 to such portion of the Original Purchase Price being converted;

           WHEREAS, MTLC effected a 10 for 1 reverse stock split following
 the execution and delivery of the Original Purchase Agreement and has
 agreed that the right to convert the "New Purchase Price" (as defined
 below) of each of the Notes, in one or more tranches, into shares of MTLC
 Common Stock, shall be at the lesser of 70% of the Market Price of the
 MTLC Common Stock or $2.50 per share, said Common Stock upon conversion to
 be paid for by cancellation of such portion of the New Purchase Price
 equal to the number of shares of Common Stock being acquired multiplied by
 the lesser of (i) or (ii) and the concurrent cancellation of all interest
 accrued from and after July 30, 199 attributable to the tranche being
 converted;

           WHEREAS, after giving effect to the reverse stock split referred
 to above, pursuant to the Offer, the accepting parties thereto, market
 conditions permitting, had agreed to exercise warrants to acquire 400,000
 shares (of which 300,00 shares were acquired by such exercise) and MTLC
 has requested that such parties either exercise warrants to acquire an
 additional 100,000 shares in whole or in part or resell to third parties
 the unexercised warrants at 30 cents per share, any such warrants to be
 warrants of Sundial and Ultra's choosing, held by Sundial, Ultra or the
 other accepting parties to the Offer, and Sundial and Ultra have
 determined to resell to such parties or their nominees concurrently with
 or following the execution and delivery hereof warrants to acquire 70,000
 shares for a purchase price of $21,00, and to exercise warrants to acquire
 30,000 shares by payment to MTLC of $75,000, to the Agent by wire transfer
 for the account of Sundial and Ultra, the Agent's account being account
 No. 042 78931 maintained with Citibank N.A., ABA No. 021000089;

           WHEREAS, Sundial, Ultra and MTLC have agreed to modify, among
 other provisions, the provisions of the Original Purchase Agreement and
 the Notes to extend the time within which the Notes may be converted and
 to modify the terms of the Notes respecting the ability of MTLC, Sundial
 and Ultra to require redemption of the Notes in whole or in part; and

           WHEREAS, MTLC has agreed to provide certain additional
 collateral for the loans evidenced by the Notes.

           NOW, THEREFORE, in consideration of the premises and other good
 and valuable consideration, receipt whereof is hereby acknowledged by each
 party hereto, the parties hereto hereby agree as of the 30th day of July,
 1999 as follows:

 Section 1.  Capitalization of Interest; Increase in Amount of Loans
 Evidenced by the Notes; Prospective Change in Interest Rate.

             (a)    As of July 30, 1999 the accrued and unpaid interest on
 the Notes was $221,200.00, of which $147,467.00 was attributable to the
 Sundial Note and $73,733.00 was attributable to the Ultra Note which
 interest the parties hereby agree to capitalize by increasing the Former
 Purchase Price of the Notes.  On or as of July 30, 1999, Sundial and
 Ultra, at the request of MTLC, hereby agree to loan an additional $250,000
 to MTLC to be secured as provided in the Original Purchase Agreement as
 herein modified, of which $166,666.67 will be loaned by Sundial and
 $83,333.33 will be loaned by Ultra, which loans will also increase the
 Former Purchase Price of the Notes.  Accordingly, the parties agree that
 the "New Purchase Price" of the Notes aggregates $1,971,200.00, of which
 $1,314,134.00 is attributable to the Sundial Note, and $657,066.00 is
 attributable to the Ultra Note.

             (b)  Effective July 30, 1999, the imputed interest rate on the
 Notes is hereby changed from 9 1/3% simple interest without compounding to
 12% simple interest without compounding so that the "New Principal Amount"
 of the Notes on the maturity date of December 31, 2002 will be
 $2,780,771.00, of which $1,863,117.00 will be the New Principal Amount of
 the Sundial Note, and $917,654.00 will be the New Principal Amount of the
 Ultra Note.  It is agreed that the interest accrual on both Notes from and
 including July 30, 1999 for the 1,249 days remaining to maturity of the
 Notes is $648.17 per day, of which $432.11 per day is attributable to the
 Sundial Note and $216.06 per day is attributable to the Ultra Note.  All
 such interest accruing on or after July 30, 1999 shall be paid at maturity
 or upon redemption or by cancellation in whole or in part in the event of
 the conversion of the Notes in whole or in part, or upon the occurrence
 and declaration of an Event of Default (which shall include any default
 under this Agreement).

 Section 2.  Reverse Stock Split.

             Prior to the date hereof, MTLC effected a 10 to 1 reverse
 stock split.  The Original Purchase Agreement is hereby revised to take
 account of such reverse stock split and all provisions thereof shall be
 deemed amended accordingly.

 Section 3.  Occurrence of Trigger Event.

             It is acknowledged and agreed that the Trigger Event referred
 to in the Original Purchase Agreement has occurred and that all warrants
 issuable to Sundial and Ultra as a consequence thereof have been issued
 and that MTLC's obligation in that regard has been fully discharged.

 Section 4.  Conversion Rate; Conversion; and Redemption.

            Any provision of the Original Purchase Agreement to the
 contrary notwithstanding, it is understood and agreed as follows:

            (a)  The Conversion Rate shall be equal to the lesser of (i)
 70% of the average Market Price of MTLC Common Stock for the 5 trading
 days preceding the receipt by MTLC of any notice of conversion, or (ii)
 $2.50 per share.  As used herein "Market Price" shall mean the average
 closing bid price as shown on the NASDAQ screen for parties bidding for
 100 or more shares as at 4:00 p.m. New York time on each such date.

            (b)  Conversion of the New Purchase Price of each Note into
 shares of MTLC Common Stock may be made in one or more tranches of not
 less than $25,000 per tranche at the option of Sundial and/or Ultra,
 provided, however, that no conversion may occur without MTLC's prior
 consent before the earlier to occur of (i) March 31, 2000, or (ii) the
 final conclusion of MTLC and affiliated companies' arbitration dispute
 with the United Mexican States.  As used herein "final conclusion" shall
 mean the first to occur of any of the following:  (a) final settlement of
 the litigation, (b) final decision from the arbitral tribunal after the
 time for appeals and motions for rehearing have expired or been decided,
 or (c) in the event of an award in favor of MTLC and/or affiliated
 companies, the payment in full in United States dollars in the United
 States of such award.  The Notes, once they shall have become convertible,
 shall remain so until paid at maturity or until redeemed by Sundial or
 Ultra and until the redemption price has been paid in full.

            (c)  All shares of MTLC Common stock required to be issued by
 MTLC upon any conversion shall be fully registered and tradeable;
 provided, however, that it is understood and agreed that, in accordance
 with NASDAQ listing requirements, the total number of shares of Common
 Stock issuable upon conversion of the Notes may not exceed 19.99% in the
 aggregate (including any conversion of the Notes prior thereto) of the ten
 issued and outstanding shares of MTLC Common Stock.  MTLC had 3,601,702
 issued and outstanding shares of Common Stock as of June 30, 1999.
 Accordingly, by way of example, were the Notes to have been converted as
 at such date, no more than 720,000 shares could have been converted, any
 balance of debt outstanding to remain fully payable in accordance with its
 terms.  By way of further example, if on the date of conversion there were
 5,000,000 shares of Common Stock outstanding, the Notes can be converted
 into 999,999 shares without regard to the conversion of other issues of
 debt into Common Stock.

            (d)  The Noteholders shall have the right, but not the
 obligation, to require the redemption of the Notes for their Discounted
 Present Value at the time of redemption at any time after but not prior to
 March 31, 2000 provided, however, that nothing contained herein shall
 affect the rights of the Noteholders upon the occurrence of any Event of
 Default.

            (e)  MTLC shall have no right to redeem the Notes.

 Section 5.  Warrant Offer Program.

             Sundial and Ultra hereby tender the following warrants to MTLC
 in exchange for the payment by MTLC to Ultra of $21,000:

             1.  Warrants owned by The Jan Chr. G. Sundt Family Trust
 entitling the Trust to acquire 39,960 shares of MTLC Common Stock.
             2.  Warrants owned by Harald Ingebrigtsen entitling Mr.
 Ingebrigtsen to acquire 30,040 shares of MTLC Common Stock.

             Sundial and Ultra hereby agree to cause the Jan Chr. G. Sundt
 Family Trust to exercise warrants entitling the Trust to acquire 30,00
 shares of Common Stock and to pay MTLC $75,000 therefor.

             Said warrants shall all be of the series expiring in October
 20002, except that 40 of the warrants held by Mr. Ingebrigtsen expire in
 February 2001, and shall automatically be deemed canceled or exercised, as
 the case may be, without presentation of certificates, upon receipt by
 MTLC of payment therefore.  Upon cancellation and exercise of said
 warrants and payment therefore, all obligations in respect of the warrant
 exercise program set forth in the Offer shall be deemed fulfilled, the
 terms of the Offer otherwise to remain in full force and effect,
 including, without limitation, the provisions of the third sentence of
 Section 4 of the Offer.

             MTLC shall cause its transfer agent to issue not later than
 August 10, 1999 30,000 unrestricted, fully registered and tradeable shares
 in the name of The Jan Chr. G. Sundt Family Trust and to deliver the same
 to the Agent, if the same be in certificated form, or by sending the
 shares by DTC electronic transfer directly to the account of the Trust
 maintained with Axiom Capital Management, Inc., Account No. 896-27266 R
 20, through Axiom's clearing agent, Bear Stearns Securities Corp., One
 Metrotech North, Brooklyn, New York 11201-3859.

 Section 6.  Definitions.

             The following terms defined in the Original Purchase Agreement
 are hereby modified to read as follows:

             "Common Stock" shall mean the authorized Common stock of MTLC
 as at July 30, 1999.

             "Conversion Rate" shall mean the whole or any portion of the
 New Purchase Price of any Note being converted divided by the lesser of
 U.S. $2.50 or 70% of the Market Price of the Common Stock prior to the
 date of receipt by MTLC of the notice of conversion.

             "Conversion Shares" shall mean the shares of Common Stock of
 the Company issuable upon conversion, in whole or in part as the context
 may require, of the Notes.

             "Discounted Present Value" with respect to any Note shall be
 based on a simple interest rate of 12% per annum without compounding and
 shall mean with respect to any Note an amount calculated in accordance
 with the following formula:
                                          n
                                         ----
                      PP+(.41069957 PP x 1249)

 wherein PP equals the New Purchase Price of a Note, n equals the number of
 days elapsed from and including July 30, 1999 to and including (A) the
 date of payment pursuant to the exercise by any Noteholder of its right of
 redemption, or (B) the date of occurrence of an Event of Default, as the
 case may be, and 1249 equals the total number of days from and including
 July 30, 1999 to and including the date of maturity of the Note (December
 31, 2002).

             "Mandatory Redemption" shall mean the exercise by any
 Noteholder, at any time after March 31, 2000, of the right to require the
 Company to redeem such Note at a price equal to the Discounted Present
 Value at the date of payment of the redemption price, which right may be
 exercised in whole or in part.

             "Principal Amount" shall mean the "New Principal Amount", being
 with respect to all of the Notes, U.S. $2,780,771.00, with respect to the
 Sundial Note, $1,863,117.00 and with respect to the Ultra Note,
 $917,654.00.

             "Purchase Price" of the Notes shall mean the "New Purchase
 Price" of $1,971,200.00, with respect to the Sundial Note, $1,314,134.00
 and with respect to the Ultra Note, $657,066.00.

             "Total Interest" in respect of the Notes shall mean the total
 interest thereon from and including July 30, 1999 to the date of maturity
 and shall be equal to $648.17 per day, or $809,571.00.

             "Warrant Exercise Price" shall mean the lesser of 70% of
 Market Price or U.S. $2.50 per share of Common Stock.

 Section 7.  Existing and Additional Security for Notes.

             (a)  It is agreed that all of the stock of MIC held by the
 Agent as security for the Notes and the other obligations under the
 Original Purchase Agreement, Pledge Agreement, Registration Rights
 Agreement and related documents, shall be held by the Agent as security
 for all such obligations as hereby amended, including, without limitation,
 the obligations to repay the New Purchase Price, interest accruing
 thereon, and the New Principal Amount.

             (b)  It is understood that MTLC and its subsidiary Eco-Metalclad,
 Inc. ("ECOM") as Sellers, propose to enter into a Stock
 Purchase Agreement providing for the sale to Geologic, S.A. de C.V.
 ("Buyers"), substantially in the form of Exhibit A annexed hereto and made
 a part hereof, of all of the issued and outstanding capital stock of the
 "Companies" (as defined in the Stock Purchase Agreement).  Concurrently
 with the execution and delivery of the Stock Purchase Agreement, which
 MTLC warrants will occur not later than August 5, 1999, MTLC or ECOM will
 jointly and severally assign to the Agent for the benefit of Sundial and
 Ultra as additional security for MTLC's obligations to Sundial and Ultra
 all of their right, title and interest in and to said Stock Purchase
 Agreement, in form and substance satisfactory to sundial, Ultra and its
 counsel; provided, however, that the U.S. $125,000 payment referred to in
 Section 1.4(e) and the U.S. $332,000 payment referred to in Section 1.4(c)
 of the Stock Purchase Agreement shall be excluded from the assignment.  In
 view of the fact that the Stock Purchase Agreement is governed by the laws
 of Mexico, MTLC will instruct its Mexican counsel to prepare and submit to
 the Agent (who shall cooperate with Mexican counsel to minimize Mexican
 legal fees) all necessary documentation (with an English language
 translation thereof if it is in Spanish) to effect the aforementioned
 assignment, which assignment must include a notification to and acceptance
 by the Buyers of such assignment.  The cooperation of the Agent shall
 enable the preparation of a Security Agreement of rights to payment of the
 purchase price under the Stock Purchase Agreement for review by Mexican
 counsel.  In the event of the failure to conclude the Stock Purchase
 Agreement by August 5, 1999, MTLC will forthwith instruct and cause its
 Mexican counsel to effect a pledge of all the shares in the Companies to
 the Agent for the benefit of Sundial and Ultra.  The assignment or pledge
 shall be in all respects acceptable to the Agent and shall constitute
 first, prior, perfected security interests in and to the collateral
 referred to therein.  There shall also be filed UCC-1 Financing Statements
 in appropriate U.S. jurisdictions in respect of such assignment.  In the
 event a definitive Stock Purchase Agreement for the sale of such stock is
 entered into after August 5, 1999, the Agent will release the shares of
 the Companies pledged to it upon compliance with the assignment and
 notification provisions referred to above.

 Section 8.  Sale of MIC Stock or Assets; Substitute Security.

             MTLC agrees that it will not proceed with the sale of any
 stock or assets of MIC without the prior written approval of Sundial and
 Ultra unless such sale will provide substitute cash or equivalent fully
 perfected security in an amount not less than the New Principal Amount of
 the Notes.  No such sale shall effect a redemption of the Notes.

 Section 9.  Proceeds From Settlement or Judgment in NAFTA Case.

             MTLC has heretofore agreed to pay from the settlement or
 judgment proceeds of the NAFTA case, if any, the following amounts and no
 others: 7% of such proceeds net of all expenses to counsel representing
 MTLC and bonus to those officers of MTLC not exceeding in the aggregate 5%
 of any such gross proceeds.

             MTLC agrees that it shall not directly or indirectly grant any
 further interests in such proceeds or agree to pay any bonus or other
 compensation or payment of any kind or type based on contingent upon or
 measured by the receipt or amount of such proceeds to any party without
 the Noteholders prior written consent.  Such consent will be granted if in
 the Noteholders opinion full compensation is made to them for any dilution
 of their interests that may occur by reason of any such further grant.

             MTLC's undertakings in this Section 9 shall not prevent the
 granting to officers, directors or employees of options to purchase shares
 of MTLC at not less than the fair market value thereof at the time of the
 grant of said options.

 Section 10. Legal Fees and Disbursements.

             Concurrently with the execution and delivery of this Agreement
 MTLC will reimburse Sundial's and Ultra's attorneys $10,000 in legal fees
 plus estimated disbursements ($1,000.00) incurred in connection with the
 preparation o this Agreement.  It is agreed that such reimbursement may be
 offset against the $250,000 in additional loan proceeds to be received by
 MTLC hereunder or from the net payment due MTLC in respect of the warrant
 exchange program as Sundial and Ultra shall direct.

  
<PAGE>
Section 11. Authorization.

             Concurrently with the execution and delivery hereof, MTLC
 shall furnish the Agent with a certified copy of resolutions of the Board
 of Directors of MTLC authorizing the execution, delivery and performance
 of this Agreement.

 Section 12. Original Purchase Agreement.

             Except as herein expressly modified by the context of this
 Agreement, the Original Purchase Agreement shall remain in full force and
 effect.

  
<PAGE>
            IN WITNESS WHEREOF, the parties hereto have executed and
 delivered this Agreement as of the 30th day of July, 1999.


                                SUNDIAL INTERNATIONAL FUND LIMITED

                                By:   /s/Donald B. Shafto
                                    ------------------------------------
                                   Donald B. Shafto, Assistant Secretary


                                ULTRA PACIFIC HOLDINGS S.A.

                                By:   /s/Donald B. Shafto
                                    ------------------------------------
                                   Donald B. Shafto, Assistant Secretary


                                METALCLAD CORPORATION

                                By:   /s/Grant S. Kesler
                                    ------------------------------------
                                   Grant S. Kesler, President