TN 03.24 - Use of Primers and Bonding Agents

INTRODUCTION
Primers and Bonding Agents are used to prepare a surface prior to the fixing of tiles. This can include:
(i) consolidation of the substrate surface (i.e. improving surface strength of friable surfaces).
(ii) reducing/controlling the porosity of the substrate thus preventing the formation of air bubbles and prolonging the flow time with levelling compounds and extending the open time of adhesives.
(iii) isolating products containing calcium sulfate (e.g. gypsum plaster and anhydrite screeds) from cement-based adhesives, thus minimising the risk of reaction between the two materials.
BAL PRIMERS AND BONDING AGENTS
- BAL PRIME APD
A modified acrylic polymer dispersion (2.5L).
- BAL BOND SBR
A water-based dispersion of styrene-butadiene copolymer.
PREPARATION
Surfaces should be free from efflorescence, laitance, dirt, dust and other loose material. They should also be free from oil, grease and other contaminants. For more specific details refer to the data sheet of the relevant adhesive, levelling compound or tanking system to be used.
HEALTH & SAFETY INFORMATION
For detailed information and safety guidance for each product, please refer to the relevant aerial Safety Data Sheet (MSDS)

TYPICAL SUBSTRATE PRIMING APPLICATIONS (refer to the TDS for more detail)
Gypsum plaster prior to the use of BAL ready-mixed adhesives
BAL Prime APD: One coat diluted 1:1 with water.
BAL Bond SBR: One coat diluted 1:4 with water.
Gypsum plaster prior to the use of BAL cement-based adhesives
BAL Prime APD: Two coats undiluted.
Allow first coat to dry before applying second coat at 90° to the first (i.e. cross coated).
BAL Bond SBR: Diluted 1:2 with water.
Allow first coat to dry before applying second coat at 90° to the first (i.e. cross coated).
Cement:Sand screeds and Concrete
BAL Prime APD: One coat diluted 1:1 with water.
BAL Bond SBR: One coat diluted 1:4 with water.
Anhydrite (Calcium Sulfate) Screeds
BAL Prime APD: Two coats.
First coat diluted 1:1 with water. Second coat undiluted.
Allow first coat to dry before applying second coat at 90° to the first (i.e. cross coated).
BAL Bond SBR: Two coats.
First coat diluted 1:4 with water. Second coat diluted 1:2 with water. Allow first coat to dry before applying second coat at 90° to the first (i.e. cross coated).
Suitable Plywood Floors (to be over boarded with tile backer board or uncoupling membrane)
BAL Bond SBR: One coat undiluted to edges, underside and upper face of board prior to fixing board into place.

BAL Prime APD: One neat coat.
Softwood Tongue & Groove Floorboards (to be over boarded with tile backer board or uncoupling membrane)
BAL Prime APD: Two undiluted coats.
Allow first coat to dry before applying second coat at 90° to the first (i.e. cross coated).
Lightweight Blockwork
BAL Prime APD: One coat undiluted - two coats if required.
If two coats - allow first coat to dry before applying second coat at 90° to the first (i.e. cross coated).

OTHER APPLICATIONS FOR BAL BOND SBR
As well as priming applications, BAL Bond SBR has other uses in the construction industry. These include:
- As an admixture and bonding agent for cement:sand mortars and concrete applications. Once cured the polymer is water and frost resistant.
- As a slurry coat when mixed with hydraulic cement or gypsum plaster.
For further, more specific information, refer to the relevant Technical Data Sheets for each product.
TECHNICAL ADVISORY SERVICE
For free expert guidance on the use of BAL products, or any aspect of ceramic tiling with BAL products, contact the BAL TECHNICAL ADVISORY SERVICE on 01782 591120.
THE BAL 25 YEAR GUARANTEE
BAL products are supplied with a 25 year product guarantee. For further details and/or copies please contact the Company’s marketing department.
NOTE
The customer must verify the suitability of any information, opinion, recommendation or advice (“information”) provided by the Company for the particular application for which any goods are intended to be used and the Company accepts no liability (whether in contract, tort or otherwise) whatsoever for any loss, damage or expense arising from the misuse of any information it supplies, nor for the use of any information in or for applications which are unsuitable or inappropriate. Building Adhesives Ltd operates a continuous research and development programme and reserves the right to alter or to update information from time to time.

“Note: Any advice, opinion or information is given to assist the use of the Company’s products on the basis that the user will ensure its suitability for the application intended. In particular the Company cannot accept liability for loss or damage which may arise from incorrect use of its products or from poor workmanship. The Company operates a continuous research and development programme and reserves the right to update information without notice.”