Custom SYSTEM 45 Masonry Patching & Coating

DESCRIPTION:

Custom SYSTEM 45 - Series products are two-component, latex-modified, cementitious compounds used for producing highly compatible aesthetic and structural repairs to masonry and concrete. They can also be used to produce stone-like finishes on a variety of other substrates.

Custom SYSTEM 45 products have been matched to over 1400 different types and colors of natural stone, concrete and manufactured masonry: 

• Limestone
• Brownstone
• Bluestone
• Granite
• Marble
• Terra Cotta
• Brick
• Stucco
• Concrete
• Slate
• Pointing mortars are also available. (For non-latex mortars, see SPEC-JOINT 46.)

USES:

Custom SYSTEM 45 products have been used extensively in Historic Landmark Restorations, and have been accepted by leading restoration authorities. System economics make the products attractive for routine commercial use, as well. This has permitted achievement of durable, inconspicuous repairs on many types of structures, including churches, university buildings, schools, hospitals, libraries, post offices, railroad stations, apartment houses, hotels, office buildings and private residences.

FEATURES:

Appearance: Excellent aesthetic results are achieved, because color and texture are closely matched to the existing masonry. Patches and coated sections can be made virtually indistinguishable from original work, and both accelerated weathering (ASTM G-53) and natural exposure testing assure long-term resistance to color change or fading. All formulations are UV-stable and non-yellowing.

Consistency: SYSTEM 45 is more reliable and consistent in appearance and performance than custom non-latex mortars or simple field-mixed mortars. Color, composition and quality are rigidly controlled in the manufacturing process, and critical ingredients are single-sourced to eliminate variations, even on projects extending over months or years and requiring many production batches. The two components are simply mixed together and applied, eliminating any influence by variations in local aggregate, cement or water compositions. Under most normal application conditions, proper curing and strength are achieved without special procedures or prolonged wet curing.

Performance: Custom SYSTEM 45 is designed to achieve excellent adhesion (>200 psi direct tensile bond), high flexural strength (>1000 psi), low elastic modulus (<100,000 psi), and superior resistance to weathering, abrasion and vibration. Mechanical strengths of each individual formulation is designed for compatibility with each particular substrate being repaired, from soft mortars to hard granites.

Permeability: Custom SYSTEM 45's latex-cement comatrix retains excellent moisture vapor permeability (>10 perms for terra cotta patch, >40 perms for sandstone patch), avoiding moisture entrapment at the patch/substrate bond line.

Thermal Expansion: Product coefficient of thermal expansion is close to typical stone expansion coefficients, allowing long-term durability in exterior exposures which are subject to wide temperature variations.(5 x 10-6 in/in/0F)

Composition: Part ``A'' is a proprietary acrylic emulsion. Part ``B'' is a cement-based blend of select graded aggregates, additives, fillers and pigments, with performance and workability-enhancing admixtures. No chlorides, added gypsum or other corrosive or deleterious additives are used.

Adhesion: Product adheres tenaciously to all types of properly prepared concrete and masonry surfaces, as well as wood, steel, polystyrene foam, and glass-reinforced cement panels.

Workability: Products are formulated for good workability under a wide range of repair situations. Product is not formulated for fast set or rapid hardening, permitting fine tooling, carving, shaving, grooving or sculpting in the period following initial set. Standard non-sag consistency allows build-up of up to 2" on vertical surfaces without sagging, up to 1 inch on overhead applications. Optional Type S superplasticized grade liquid allows material to be cast in forms without changing strength or color.

Safety: Products are non-corrosive, non-flammable, non-combustible and contain no toxic solvents, monomers or diluents. Low odor allows interior as well as exterior application.

APPLICATION:

1. Surface Preparation: Durable, effective repairs require clean, sound substrates for proper bonding. Remove all contaminants, coatings, efflorescences, unsound masonry and loose mortar. If large or deep repairs will be otherwise unsupported, mechanical keying or anchoring is recommended. The decisions whether to anchor and how frequently to provide anchors should be based on structural

 requirements, the condition of the substrate, patch dimensions and weight, and the extent to which patch integrity will otherwise rely on adhesion alone. Such decisions are frequently best made in consultation with a qualified professional. In all cases, good restoration practices should be followed.

2. Application: Custom SYSTEM 45may be applied by trowel, spray, casting-in-place or other techniques commonly used in structural repair work. Products are formulated for good workability under a variety of application methods and conditions, although custom formulation for a particular application method, (e.g. casting in place, or shotcreting), is available.

Masons accustomed to working with latex-modified mortars will have no trouble working with Custom SYSTEM 45. With practice, a wide range of finishes may be produced under a variety of working conditions. While the details of each application will vary, the following general guidelines are common to most Custom SYSTEM 45 applications:

a. Minimum temperature is 50F (10C). Air, surface and product temperatures must all be above minimum at time of application, and must be maintained above minimum until product has dried thoroughly. Drying time is affected by temperature, wind velocity, relative humidity and patch thickness. Accordingly, through-drying time may vary from an hour or two (thin patches, warm and dry weather) to several days (deep patches, cool and damp conditions). Inadequate temperature may cause poor appearance.

b. Do not overwork. Latex-modified mortars may tend to pull or tear if overworked. For best results, finish soon after application. Build up deep repairs in uniform ``lifts''. If required, dampen tools with clean water and then daub dry; Do not retemper, sponge float, wet repeatedly or thin mix excessively.

c. Cold Weather: Store SYSTEM 45 in a heated area until just before use. Hot water rinsing of surfaces can help achievement of minimum temperatures under marginal conditions. If auxiliary heating is used, do not direct hot exhaust gases at patches. Moderate temperatures and air flows work best, and heated air is preferable to burner exhausts, which are high in CO and CO₂.

d. Hot Weather: Store materials in a cool place, out of direct sun. Dampen surfaces thoroughly with cold water prior to application to reduce suction and slow down product drying. Do not retemper with repeated liquid additions. Lightly mist any surfaces which dry too rapidly, allowing a minimum of 2 hours' moisture after application. Do not thin excessively to compensate for rapid drying. Over-thinned or rapidly-dried surfaces may develop plastic cracking shortly after application.

e. Priming: For best adhesion, do not apply product to dry surfaces. Slurry coating is the preferred method of priming for trained applicators. As a minimum, dampen with clean water, but leave no standing or excess water, or apply a primer coat of neat SYSTEM 45A liquid, taking care to avoid rundown on areas not being patched. When using latex primer, apply patching compound within 4 hours of priming.

f. Mixing: Best results are obtained when Part A and B are mixed together at consistent proportions. Determine the powder to liquid proportion which works and handles best for your particular application and Custom SYSTEM 45 formulation, and then measure the same proportions for each mix. Mix ratios are generally between 5:1 and 7:1 by weight, or between 3 qts. (3 liters) and 5 quarts (5 liters) per 45-pound pail. Mechanical mixing, using a mortar mixer or slow speed drill mixer is preferred, although good results can also be obtained bythorough hand mixing. Mix for at least 2 - 4 minutes, but avoid whipping excess air into the mix, and do not mix more material than can be applied in about 15 minutes. The desired mix consistency is a dry, non-sticky, workable paste.

g. Interruption: If work will be interrupted due to drop width or other limitations, always try to work to an inconspicuous ``break'', such as a column line or ledge. On masonry exhibiting wide unit-to-unit color variations, more than one custom color may be needed to achieve completely inconspicuous repairs. Alternatively, an intermediate shade should be selected, and a thin parge coat of Custom SYSTEM 45 may be applied to entire units which are repaired.

h. Curing: Product should be allowed to dry cure after a brief initial moist period. Do not apply when rain is likely before material has through-dried. Application in direct sun will produce temporarily robust colors, which will tone down to the ``normal" color after a brief period of natural exposure. Avoid working in direct sun when possible. In overcast weather, somewhat more muted shades may be achieved. Light stoning or rubbing can also be used to reduce sun-dried color intensity, if desired, and application of a light sealer such as SYSTEM 90-W will intensify slightly muted shades. For greater color intensification, use SYSTEM 90-II or 90-II Plus. For best long-term durability, SYSTEM 90 should be applied to all masonry and patch surfaces. In some cases, rapidly falling temperatures or rising humidity may result in slight efflorescence, or whitish discolorations. These will weather away with natural exposure, or can usually be eliminated by treating surfaces with SYSTEM 90-II.

3. Storage & Handling: Proper care should be taken when handling cement-based materials, to avoid skin and eye contact and avoid breathing dust. Some formulations contain free silica, and proper NIOSH-approved silica dust filters should be used. Products should be stored in a dry place, off the ground or floor, at moderate temperatures. KEEP FROM FREEZING. For complete safety and handling information, refer to Material Safety Data Sheets furnished with this product.