ITEM 446 CLEANING, PAINT AND PAINTING

Transcription

1 ITEM 446 CLEANING, PAINT AND PAINTING Description. This Item shall govern for the type, source, quality, testing, surface cleaning, surface preparation and application of paint. This Item also includes protection of all traffic, property and/or persons upon, underneath or near the structure and for the protection of all parts of the structure during cleaning and painting operations Materials. (1) General. Paints for System I and System II and appearance coats for these systems shall be in accordance with Departmental Materials Specification D Information about paint characteristics, thinner requirements, etc., and copies of Specification D are available from the Texas Department of Transportation, Division of Materials and Tests, 125 East 11th Street, Austin, Texas Paints for System III shall be in accordance with Departmental Materials Specification D Information about paint characteristics, thinner requirement, etc., shall be obtained from the paint supplier. Copies of Specification D are available from the Texas Department of Transportation, Division of Materials and Tests, 125 East 11th Street, Austin, Texas (2) Condition. Paints to be applied shall be thoroughly mixed and strained. Mixing shall be by mechanical methods and shall be such that the paint is rendered to be a completely homogeneous mixture free of lumps, skins or agglomerates, and shall contain all pigments, vehicle solids and thinners required in the original formulation. Paint containers shall be kept tightly covered and protected from the weather when not in use. (3) Thinning. Paint may be adjusted to the correct application consistency by the use of properly applied heat not to exceed 150 F, or by use of suitable thinners. Caution should be exercised since most paints and thinners are flammable. The use of heat to thin epoxy paints may decrease the useful pot life of these paints Paint Systems. (1) Prime Coat. (a) Protection System I (800 Prime Coat) requires Class "B" blast cleaning, with a minimum of a 4.0 mil dry film thickness of prime coat paint, applied in a minimum of two coats and a minimum of a 2.0 mil dry film thickness of appearance coat paint. (b) Protection System II (810 Prime Coat) requires Class "A" blast cleaning, with a minimum of a 3.5 mil dry film thickness and a maximum 10.0 mil dry film thickness of prime coat paint, applied in a minimum of two coats and a minimum of a 2.0 mil dry film thickness of appearance coat paint. (c) Protection System III (Inorganic Zinc) requires Class "A" blast cleaning, with a minimum of a 3.0 mil dry film thickness of Inorganic Zinc prime coat paint; two (2) coats of System III Epoxy Zinc prime coat paint on the surfaces to be in contact with concrete; a minimum of 2.0 mils dry film thickness of System III Epoxy Intermediate coat paint on all surfaces excluding those to be in contact with concrete, two (2) coats of System III Epoxy Intermediate coat paint on surfaces to be in contact with concrete and a minimum of a 2.0 mil dry film thickness of System III Urethane appearance coat paint. (d) A Special Protection System when specified will require the type of cleaning, the type and thickness of prime coat and other coats, as shown on the plans, or in Special Provisions to this Item.

2 (2) Appearance Coat. The final appearance coating for Systems I and II shall be aluminum (slow dry or fast dry), green or grey as shown on the plans. Any of these colors may be designated with a particular system. Appearance coats of other colors, when required, will have the type of paint, color and mil coverage shown on the plans. System III Urethane appearance coat paint shall be concrete grey in color unless shown otherwise on the plans. (3) System and Color Designation. All structural steel except "Weathering Steel" shall be cleaned and painted in accordance with the paint system and appearance coat shown on the plans or in the specifications. Steel designated as "Weathering Steel" shall not be painted unless otherwise shown on the plans. When no paint system is specified, the paint system shall consist of Protection System I prime coat and a gray appearance coat. The Contractor may request in writing to substitute System II for a specified System I subject to the approval of the Engineer Source of Supply. All paints required to comply with Departmental Materials Specification D shall be purchased from the Department unless otherwise shown on the plans or in the specifications. All paints required to comply with Departmental Materials Specification D shall be purchased on the Open Market. Except for quantities of paint of 100 gallons or less, the Contractor shall give the Engineer a minimum of 120 days notice as to where the requested quantities of paint will be needed and the required dates. This notification shall be accomplished on a standard Department form supplied by the Engineer. Paint is stored by the Department in the warehouses located at Seguin, Athens and Post, Texas. Paint will usually be supplied from the warehouse nearest the designation; however, the right is reserved to supply from any warehouse in case of necessity. Shipments will be made direct to the Contractor at the location he designates, with transportation charges to be paid by him. The Contractor may obtain the paint by freight or at a location specified by the Engineer. The Contractor shall place his order for State-stocked paint in accordance with the above, through the Engineer. All paints purchased from the Department will be charged to the Contractor at prices in accordance with the plans. Reimbursement to the State will be accomplished by making deductions from the Contractor's monthly and/or final estimate for the cost of paints purchased. The Contractor shall not use any of these paints on any work which is not required by or which does not constitute a part of the contract. The Contractor shall return all remaining undamaged and unopened containers of paint to the District Warehouse within 10 days after completion of all painting and credit will be given for the remaining paint based on the Contractor's original purchase price for the paint Responsibility for Hazards. Some paints are harmful to the health. All paints shall be handled according to the information contained on the paint safety data sheet. The Contractor shall be responsible for safety during all cleaning and painting operations. Unless shown otherwise on the plans, the Contractor, at his expense, shall exercise necessary precautions to contain refuse, dust and paint overspray generated during cleaning and painting operations. Containment shall be such that all falling material is contained and collected for disposal. Noncontainment of airborne particles is permissible provided they are not visible over 100 feet from the actual cleaning or painting operation. A skimmer shall be used when cleaning and painting is over bodies of water. Disposal of collected refuse shall be in accordance with Federal, State and Local rules and regulations.

3 Equipment. Equipment used in cleaning and painting shall be of adequate capacity and have sufficient gauges, filters, agitators, regulators and moisture separators to insure delivery of clean dry air at the proper pressure and volume to permit satisfactory performance of the work. All equipment and accessories shall be maintained in good working order. All spray equipment shall be adequate for the type of paint being used and shall be equipped with spray heads adequate to provide a smooth, uniform coat of paint. Equipment used for spray painting shall have adequate provisions for separation of moisture from any air stream in contact with the paint. All spray equipment shall evidence good maintenance and be essentially free of old dried coatings on the exterior surfaces. Inside surfaces to which paint is likely to come in contact shall be completely free of any and all dried coatings or other foreign matter. Equipment not in compliance with the above will not be considered suitable. If airless spray equipment is used, working regulator and air pressure or fluid pressure gauges shall be used. If conventional air spray equipment is used, independent fluid pressure and atomization pressure regulators and gauges shall be used. Fluid and air hoses for conventional air spray equipment shall be a minimum of 1/2 inch I.D. with a maximum length of 75 feet. Fluid hoses for airless spray equipment shall be a minimum of 5/16 inch I.D. and a maximum length of 75 feet. During painting operations, paint pots shall not be more than 20 feet above or below level of spray application of paint. Fluid hoses shall not be allowed to sag more than 10 feet below the level of the bottom of the paint pot or actual spraying operations whichever is the lowest point. All hoses shall be serviceable and shall not show cracks or deterioration. Paint pots or other suitable containers from which the paint is dispensed shall be equipped with agitators which shall be in operation at all times that paint is in the pot Construction Methods. (1) Rigging, Scaffolding, Etc. Contractor shall make available safe and adequate access to all parts of the work for proper inspection. Rigging, scaffolds, etc., shall not be placed on or hung from previously painted surfaces until the previously applied coating has had a minimum of 48 hours curing time. Previously painted surfaces, to which rigging, scaffolding, etc., will be placed on or hung from, shall be protected with an approved padding to minimize damage to the previously applied coating. All coating damage as a result of rigging and scaffolding shall be repaired as directed by the Engineer. (2) Cleaning and Preparation of Surfaces. Surfaces to be painted shall be completely free of oil, grease, moisture, dirt, sand, overspray, welding contamination (slag and/or acid residue); loose or flaking mill scale, rust or paint; and be free of any other conditions that will prevent the paint from forming a continuous, uniform, tightly adhering film. All steel splinters (hackles) raised or evident during cleaning shall be removed. When blast cleaning is required, areas from which steel splinters (hackles) are removed shall be reblasted. All surfaces which are to be painted shall be subjected to the following test to determine if they are contaminated with loose particles. Press a strip of filament tape onto the surface in question by rubbing with moderate thumb pressure four times. Leave approximately two (2) inches of one end of the tape free from the surface. Grasp the free end of the tape and remove the tape from the surface with a sharp pull. The surface shall be considered as contaminated if the removed tape exhibits particles clinging to the tape.

4 Prior to other cleaning operations, grease-like contaminants shall be completely removed with clean petroleum solvents or other methods approved by the Engineer. This requirement shall be applicable to all coats. All welds deposited using the shielded metal arc welding process, shall be thoroughly flushed with fresh water and allowed to become thoroughly dry before cleaning. Unless a particular class of cleaning is specified, any effective method for removal of rust, scale and dirt, such as the use of blast cleaning, hand or rotating metal brushes, scrapers, chisels, hammers, flame cleaning or other means will be acceptable. When blast cleaning is required, all flame-cut edges shall be blasted to produce a noticeable dense anchor pattern over the entire flame cut surface. When a class of cleaning is specified, the following requirements shall apply in addition to the above requirements: (a) Class "A" Blast Cleaning. Class "A" Blast Cleaning is defined as the removal of all visible rust, paint, mill scale and other forms of contamination. The blasted area shall exhibit a uniform surface appearance when viewed with the unaided eye (20-20 vision). (b) Class "B" Blast Cleaning. Class "B" Blast Cleaning is defined as the removal of all oil, grease, dirt, rust scale, loose mill scale, loose rust and loose paint or coatings. Tight mill scale and tightlyadhered rust, paint and coatings are permitted to remain. Each square inch of surface area to be cleaned shall be exposed to the abrasive blast pattern sufficiently to expose several flecks of the underlying metal. (c) Class "C" Cleaning. Class "C" cleaning is defined as the removal of exposed rust, peeling or flaking paint and oxidized paint. These areas shall be cleaned by hand scraping and/or wire brushing, or any other method approved by the Engineer, so that all loose rust, peeling or flaking paint, and oxidized paint are removed. All edges of coatings surrounding cleaned areas shall be feathered into sound, tightly-adhering coatings. (3) Painting. (a) General. Each coat of paint shall be applied to clean, dry, firm surfaces complying with all specification requirements. Each coat shall dry to form a smooth, continuous, tightly adhering film of uniform thickness and appearance, free of sags, runs, pinholes, holidays, and overspray. Care shall be taken to insure that all surfaces to which paint is to be applied are free of all forms of contamination. All coats shall be applied by spray except that any method of application approved by the Engineer may be used to paint inaccessible areas. When System I or II is specified and the steel and the ambient temperature are both above 60 F, the required second coat of primer may be applied before the first coat has cured but in no case less than two (2) hours after the application of the first coat. All runs, sags and other defects in a coat shall be repaired before application of any subsequent coat. Immediately prior to painting, steel surfaces or surfaces of previously applied coats of paint shall be cleaned by blowing with clean compressed air, brushing or a combination of the two (2) in order to remove traces of dust or other foreign particles. When directed by the Engineer, the surfaces of previously applied coatings shall be either washed with clean, fresh water or a mild detergent water followed by a complete and thorough rinse with clean, fresh water. Paint shall not be applied to any surface containing moisture discernible with the eye or by the following test:

5 If temperature and humidity conditions are such that moisture is likely to condense upon the surface, a small area thereon shall be moistened with a damp cloth to apply a clearly defined, thin film of water. If this thin film evaporates within fifteen minutes, the surface shall be considered safe to paint. Paint shall not be applied when the air temperature is below 40 F; nor when the temperature is expected to drop below 40 F within two (2) hours after application. No paint shall be applied when impending weather conditions might result in injury to fresh paint. For all systems the dry film thickness will be measured according to Test Method Tex-728-I. If in the opinion of the Engineer, there is an objectionable amount of dust in the atmosphere, the Contractor shall, at his own expense, take necessary precautions to prevent dust and dirt from coming in contact with freshly painted surfaces or with surfaces before the paint is applied. Where paint is likely to be sprayed on traffic, the Contractor, at his own expense, shall provide a shield that will satisfactorily protect the traffic from paint. Care shall be taken when painting steel that is in contact with concrete to insure full coverage of the steel with a minimal amount of paint onto the concrete surface. In no case shall the paint extend more than four (4) inches onto the concrete surfaces. When painting is complete, the only visible paint on concrete surface shall be the finish coat. Excessive and/or objectionable paint on concrete surfaces shall be removed, at the Contractor's expense, in a manner approved by the Engineer. (b) Workmanship. All painting shall be done by skilled painters. Application of modern specialized coatings requires painters knowledgeable about the characteristics of the various coatings, solvents and substrates. The painter also must be capable of adjusting equipment and application techniques as dictated by the type paint, weather conditions, environment, size and shape of surface being painted. Any painter who, in the opinion of the Engineer, does not adjust his equipment so that he can apply the coating in a uniform full wet coat free of runs, sags, holidays or overspray will not be considered a skilled painter. Spray applications of coatings shall be essentially 90 degrees to the surface and from 10 to 18 inches from the surface as necessary to apply a full wet coat of paint free of overspray, runs, sags and holidays. Any spray painter who does not consistently spray in this manner and/or extends the spraying stroke such that paint is being applied to the surface at an angle of less than 80 degrees shall not be allowed to spray paint. (c) Shop Painting. Unless otherwise provided in the contract or approved in writing by the Engineer, the initial cleaning and application of required prime coat paint shall be done by the Fabricator or his designated cleaning and painting contractor prior to shipment of the steel to the job site. After all fabrication work is completed and has been tentatively accepted, all surfaces to be painted shall be cleaned and painted with the required prime coat. Pieces shall not be loaded for shipment until coatings are thoroughly dry. No painting shall be done after material is loaded for shipment. Erection marks for field identification of members shall be painted upon previously painted surfaces. Surfaces to be in contact after shop or field bolting shall be cleaned but not painted except when System III is specified. When System III is specified, surfaces to be in contact after shop or field bolting shall be cleaned and painted with the inorganic zinc primer only before bolting. Surfaces within four (4) inches of a field weld that joins main stress carrying members and within two (2) inches of fillet welds, including the far side, joining diaframs or lateral bracing to stiffeners or gusset plates shall be free of paint. These unpainted surfaces shall be blast cleaned and coated with raw linseed oil. After welding is completed, the areas shall be cleaned and painted in accordance with the required system. When System III is specified, inorganic zinc primed surfaces within four (4) inches of the above mentioned

6 surfaces shall be free of intermediate coating. Machine-finished surfaces which are in sliding contact in the structure shall be cleaned and coated with a hot mixture of tallow before being shipped. This refers particularly to pins and pinholes. The composition used for coating these machine finished surfaces shall be mixed in the following proportions: 4 lbs. pure tallow 2 lbs. zinc oxide 1 quart pure raw linseed oil Alternate mixtures may be used in lieu of the above with the written approval of the Director of Materials and Tests. Unless otherwise shown on the plans or exempted above, the surfaces to be shop painted will include the rolling faces of rockers and base plates, all surfaces of bearing plates, and all surfaces of iron or steel castings, whether or not such surfaces are milled. Unless otherwise shown on the plans, the top of the top flange of I-beams and/or girders which will be in contact with concrete will require cleaning and painting in accordance with the system specified except as modified below. For Systems I and II, the minimum and/or maximum dry film thickness of prime coat requirements will apply only to one and one half (1-1/2) inches in from the outside edges of the top of the top flange. The remainder of the top flange shall exhibit a tightly adhering paint film. For System III, the top of the top flange and other areas to be in contact with concrete shall be painted a minimum of one and one half (1-1/2) inch in from the outside edge of the surface to be in contact with concrete with the inorganic zinc primer. A light coat of inorganic zinc primer is permissible on all surfaces to be in contact with concrete. As the inorganic zinc primer on each fabricated member is approved for thickness and other applied film characteristics, all surfaces of the inorganic zinc primer shall be thoroughly wetted with a fine mist of potable water. When all surfaces are completely dry, the surfaces to be in contact with concrete that exhibits metal oxidation and/or mud-cracking of the inorganic zinc primer shall be recleaned to the specified requirements. Cleaning shall be into the inorganic zinc primer applied to the edges of these surfaces sufficient to ensure removal of all contaminants. Care shall be taken to prevent damage to the inorganic zinc primer applied to other surfaces of the member. After surfaces to be in contact with concrete are cleaned, they shall be coated with two (2) coats of System III epoxy zinc primer applied at three (3) to five (5) mils wet per coat with a minimum of one (1) hours and a maximum of 48 hours between coats. In not less than 24 hours nor more than 96 hours after the application of the second coat of epoxy zinc primer, these same surfaces shall be coated with one (1) coat of System III epoxy intermediate coating, applied at four (4) to six (6) mils wet. The remainder of the inorganic zinc primer surfaces shall be coated with System III epoxy intermediate coating in accordance with the requirements shown elsewhere in this Item. Shop drawings shall reflect the areas of girders and/or flanges which are not to be painted. (d) Field Cleaning and Painting. When erection or maintenance work is complete, including all bolting, welding, straightening of material, etc., and all concrete has been placed, and the Engineer has examined and approved the work, all unpainted areas and areas wherein the shop applied prime coat has been damaged or fails to meet specification requirements shall be cleaned in accordance with the method required under the paint system specified. Cleaning shall be sufficiently into the sound shop applied prime coat to ensure removal of all contaminants. Edges of sound paint around cleaned areas shall be feathered. Cleaned areas shall be painted with the required prime coat. Painting shall overlap onto the surface of the shop applied paint surface sufficient to form a sealed edge. When System III is specified, all unpainted

7 areas shall be painted with the inorganic zinc primer, all spot repair areas shall be painted with the epoxy zinc primer. Prior to application of the intermediate coating to the unpainted area painted with inorganic zinc primer, the inorganic zinc primer surface shall be thoroughly wetted with potable water either by fine spray or clean wet rag. The protective coating on machined surfaces and pins, specified in Section (3)(c) shall be completely removed as directed by the Engineer for removal of grease and oil. (e) Appearance Coat. After field painting in accordance with Subarticle (d) is complete and tentatively approved by the Engineer, the required appearance coat may be applied. Previously applied paint film including field touch up requires a minimum cure time as shown in the table below, prior to the application of appearance coat. Temperature 77 F and above 65 to 77 F 55 to 65 F 40 to 55 F System I & II Days Cure, Min. System III Intermediate test. When the cure of previously applied paint is in doubt, the cure can be determined by the following Using moderate to heavy pressure, place thumb on paint surface and apply a twisting motion. If the paint film gives or twists with the thumb, the coating is not thoroughly cured. Prime coat and intermediate coat surfaces shall be cleaned by any method approved by the Engineer which does not damage the paint to remove all dirt, grease, concrete, overspray and any other substance that may impair adhesion prior to the application of the appearance coat. At the time of acceptance of the structure, the painted portion thereof shall present an even and uniform appearance throughout. (f) Paint Improperly Applied. To uncover evidence of improperly applied paint, the Engineer may, at any time during construction, explore underneath the surface of any paint coats already applied. Whenever unsatisfactory conditions are found, the Engineer may require any and all necessary remedial measures as follows: All paint which has been applied improperly, applied to improperly cleaned surfaces, fails to dry and harden properly, fails to adhere tightly to underlying metal or other paint film, or does not evidence a normal, workmanlike appearance in conformance with these specifications, shall be repaired or completely removed and replaced at the expense of the Contractor. When the final field coat does not have a uniform color and appearance throughout the structure, it shall be corrected by the use of whatever additional coats or other corrective measures found to be necessary. Freshly applied paint which has not yet set, shall be removed with the use of suitable solvents. Removal of dried paint films shall be either by means of blast cleaning, scraping, or flame torches meeting the approval of the Engineer. (4) Handling, Storage and Shipping. All blocks, chains, slings, braces, clamps, etc., used in the handling, moving, storing and shipping of painted members shall be padded in such a manner that the paint will not be damaged.

8 (5) Cleaning and Painting Existing Structures. Unless otherwise shown on the plans, existing steel structures to be cleaned painted shall receive a Protection System I prime coat and a gray appearance coat. When Class C cleaning is required, all cleaned areas shall be spot primed and appearance coated to the requirements of the paint system shown on the plans Measurement. Unless otherwise shown on the plans, no measurement will be made for the work to be done or the materials to be furnished under this Item, but it shall be considered subsidiary to the various bid items in the contract. When "Cleaning, Paint and Painting" is specified on the plans to be a pay item, the work and acceptable materials will be paid for by the lump sum for each structure unit as shown on the plans Payment. The work performed and materials furnished as required by this Item will not be paid for directly but will be considered subsidiary to the various bid items of the contract, unless otherwise specified as a pay item in the contract. When "Cleaning, Paint and Painting" is specified as a pay item, the work performed and materials furnished in accordance with this Item and measured as provided under "Measurement" will be paid for at the unit price bid for "Cleaning and Painting Existing Structures," "Cleaning and Painting Existing Railing," or "Cleaning and Painting Existing Steel Piling" for the system specified. This price shall be full compensation for cleaning, spot painting, and painting; for furnishing protection of traffic, scaffolding and paints; for disposal of all refuse; and for all labor, equipment, tools and incidentals necessary to complete the work.