PLASTER-WELD®

The original plaster bonding agent, is a patented formulation incorporating polyvinyl acetate homopolymer.

DESIGNED FOR INTERIOR USE ONLY. High performance bonding of one-coat finish plaster and/or two and three coat work to concrete ceilings, walls, columns, beams and other structurally sound surfaces. Plaster-Weld® prepares the surface to allow you to plaster directly to concrete over electric radiant heat cable, and to bond cement mortar beds to smooth concrete for installation of rigid foam insulation. Concrete, brick, block, glass, ceramic tile, wallboard, metals (e.g. sheet lead in x-ray rooms), and marble are suitable sound surfaces, structurally. Use Plaster-Weld® over paints having oil, rubber, or vinyl bases, and over silicone-treated surfaces.

To bond new plaster to any structurally sound interior surface...interior use only.

GUIDE SPECIFICATIONS

Divisions 3 & 9
1. General
1.1 PRODUCT HANDLING
a. Deliver Plaster-Weld® to job in original container with seals unbroken and use without reducing.
b. Materials Storage: Protect Plaster-Weld® from freezing.

1.2 ENVIRONMENTAL CONDITIONS
a. Air and surface temperatures must be above freezing during application of Plaster-Weld®.

1.3 PROTECTION
Protect adjacent finish surfaces with masking tape, soap powder emulsion, or a commercial product, specially formulated for protective use in plastering.

2. Products
2.1 MATERIALS
a. Bonding Agent: Plaster-Weld®, Larsen Products Corp., Jessup, Maryland (NOTE: Show bonding agent in cross section detail.)

3. Execution
3.1 PREPARATION
a. Surfaces to receive Plaster-Weld® MUST BE STRUCTURALLY SOUND AND CLEAN, free from loose material, dust, dirt, oil, grease, wax, loose paint, mildew, rust, laitance, or efflorescence. Form release agents, curing compounds, hardeners and sealers used on bonding surfaces must be compatible with Plaster-Weld®.

3.2 INSTALLATION
a. Application of bonding agent: Apply Plaster-Weld® uniformly using brush, roller or spray to form a continuous pink film over the entire surface. Allow to dry one hour. (NOTE: Painted surfaces must be sound, washable and firmly adhered to the substrate. Glossy painted surfaces should be dulled with an abrasive. Wait 60 days before applying bonding agent over newly painted surfaces. Application of wallpaper to newly bonded plastered surfaces should be delayed 90 days. Do not apply Plaster-Weld® to underside of concrete roof decks.)
b. Inspection of bonding agent: Prior to applying plaster, inspect bonding agent application to assure a continuous pink film over the entire bonding surface. Reapply Plaster-Weld® over areas not satisfactorily covered.

3.2.1 APPLICATION ONE-COAT PLASTER: Apply a white skim coat of plaster 1/16 to 3/16 inch thick over Plaster-Weld® direct to concrete ceilings and other structural surfaces as shown and specified (the mixing, application and finishing of white coat shall be as specified for regular white finish coat). At contractor's option, Plaster-Weld® and a white skim coat of plaster may be applied on interior ceilings, walls, beams and columns in place of smooth or rubbed concrete surfaces as shown or specified. (NOTE: Plastering can begin immediately as soon as bonding agent is dry to the touch (allow 1 hour) or delayed a week to 10 days with no effect on bond.)

3.2.2 APPLICATION OF TWO AND THREE COAT PLASTER: Apply scratch coat a minimum of 3/8 inch thick over Plaster-Weld® to surfaces as shown and specified. Allow to dry 24 hours (follow with two and three coat applications). (NOTE: Minimum drying time of 24 hours between coats is important to prevent moisture in second coat from penetrating the scratch coat and flooding the bond film.)

3.2.3 APPLICATION OF PLASTER OVER ELECTRIC HEATING CABLE: Contact Larsen Products for guide specifications.

3.2.4 PATCH PLASTER OVER PLASTER-WELD® following work of other trades.

TECHNICAL DATA

See Table 1: Performance Properties.

STANDARDS & APPROVALS

ASTM C 631; Military Specification, MIL-B-19235C (YD); General Services Administration Specification for Bond Adhesive; Corps of Engineers Specification CE-240.01; Canadian Standard CSA A 261; Approved: New York City Board of Standards & Appeals under Call. No. 626-52 SM; City of Los Angeles Board of Building and Safety Commissioners (Research Report No. 2463).

ac...availability/cost

Plaster-Weld® is available from building supply dealers throughout the United States and Canada. Obtain local quotations to determine costs.

Coverage: 300 to 400 sq. ft./gallon.

Packaging: 55 gal. drum, 5 gal. pail, gal., and qt. Canada: available in standard litres.

Color: Pink (non-bleeding)

LARSEN
PRODUCTS CORP.
8264 Preston Court
Jessup, Maryland 20794
(800) 633-6668