Technical Procedures Disclaimer
Prior to inclusion in GSA’s library of procedures, documents are reviewed by one or more qualified preservation specialists for general consistency with the Secretary of Interior Standards for rehabilitating historic buildings as understood at the time the procedure is added to the library. All specifications require project-specific editing and professional judgement regarding the applicability of a procedure to a particular building, project or location. References to products and suppliers are to serve as a general guideline and do not constitute a federal endorsement or determination that a product or method is the best or most current alternative, remains available, or is compliant with current environmental regulations and safety standards. The library of procedures is intended to serve as a resource, not a substitute, for specification development by a qualified preservation professional.
We’ve reviewed these procedures for general consistency with federal standards for rehabilitating historic buildings and provide them only as a reference. Specifications should only be applied under the guidance of a qualified preservation professional who can assess the applicability of a procedure to a particular building, project or location. References to products and suppliers serve as general guidelines and do not constitute a federal endorsement nor a determination that a product or method is the best alternative or compliant with current environmental regulations and safety standards.
- This procedure includes guidance on removing rust stains from ceramic tile. Rust stains may be caused by water deposits containing large amounts of iron.
- For additional information on the preservation, maintenance, repair and replacement of ceramic tiles, see 09310-02-S.
- See 01100-07-S for general project guidelines to be reviewed along with this procedure. These guidelinescover the following sections:
- Safety Precautions
- Historic Structures Precautions
- Quality Assurance
- Delivery, Storage and Handling
- Project/Site Conditions
- Sequencing and Scheduling
- General Protection (Surface and Surrounding)
These guidelines should be reviewed prior to performing this procedure and should be followed, when applicable, along with recommendations from the Regional Historic Preservation Officer (RHPO).
- Clean, potable water
- Clean, soft cotton cloths or cotton pads
- Additional Materials Specifically for Fresh Stains:
- Granular Cleaner: A heavy duty cleaning compound containing trisodium phosphate (TSP) such as "Spic- n-Span", or approved equal.
- Additional Materials Specifically for Heavy Stains:
- Oxalic Acid Stain Remover Compound such as "Zud", (available at grocery stores), or approved equal.
- Additional Materials Specifically for Set Stains:
- Oxalic Acid Crystals
Naval Jelly: Available in paint stores.
- Whiting or talcum powder
- Plastic sheeting
- Oxalic Acid Crystals
- Additional Materials Specifically for Persistent Stains:
- Lemon Juice
- Other Rust Removers: "Whisk-Away", "Pumie Scouring Stick". Follow label instructions.
- Soft paint brush
- Glass or ceramic containers for mixing any poultices/solutions
- Wooden utensil for stirring the ingredients
- Wood or plastic spatula
- Masking tape
3.01 ERECTION, INSTALLATION, APPLICATION
NOTE: CLEAN USING THE GENTLEST MEANS POSSIBLE.
- For Fresh Stains:
- Apply the granular cleaner with a damp cloth or pad and rub vigorously until the stain is removed.
- Rinse thoroughly with clean, clear water and wipe dry with a clean, soft cloth.
- For Heavy Stains:
- Apply an oxalic acid stain remover compound to the dampened area. Scrub with a soft damp cloth.
- Repeat the process as necessary to remove the stain.
- Rinse thoroughly with clean, clear water.
- Set Stains:
- Create a poultice by dissolving oxalic acid crystals in hot water; add enough whiting or talcum powder to make a soft paste.
- Using a wood spatula, apply the poultice to the stained area and allow to dry.
- Rinse thoroughly with clean, clear water and dry with a soft cloth.
- Allow naval jelly to remain on the surface for at least 30-60 minutes, or longer if necessary until the stain disappears.
- Rinse the surface with clean, clear water and allow to dry.
- Try using a commercial rust remover. Follow manufacturer's instructions.
- For Persistent Stains:
- Mix a combination of borax and lemon juice together into a paste.
- Cover the stain with the paste and allow to dry.
- Rinse the area with clear water and dry with a clean, soft cloth.
- Repeat the process if necessary.
- Try using a commercial pumice bar: Rub the stain with the bar to remove as much of the stain as possible.
- Rub the stain with the bar to 4remove as much of the stain as possible.
- Rinse thoroughly with clean, clear water and dry with a clean, soft cloth.