Plaster Weld Guide Specifications
Divisions 3 & 9
1.2 Environmental Conditions
- Deliver Plaster-Weld® to job in original container with seals unbroken and use without reducing.
- Materials Storage: Protect Plaster-Weld® from freezing.
- Air and surface temperatures must be above freezing during application of Plaster-Weld®.
- Protect adjacent finish surfaces with masking tape, soap powder emulsion, or a commercial product, specially formulated for protective use in plastering.
- Bonding Agent: Plaster-Weld®, Larsen Products Corp., Jessup, Maryland
- 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 must be compatible with Plaster-Weld®.
- 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.
- 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
3.2.2 Application of Two and Three 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.)
3.2.3 Application of Plaster over Electric Heating Cable:
- Apply scratch coat a minimum of 3/8 inch thick over Plater-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.)
3.2.4 Patch Plaster Over Plaster-Weld® following work of other trades
- Contact Larsen Products for Guide Specifications.