Weldbond : Working with Cement, Concrete, & Brick
Bond new-cement mixes to old concrete!
With Weldbond, no hacking, keying or joint raking is required. Thoroughly clean the surface, vacuum if possible.
For porous surfaces: Thin 1 part Weldbond with 5 parts water. Apply this sealer to old concrete and allow to dry. Apply 3 parts Weldbond with 1 part water. While still tacky, apply new cement on concrete. For non-porous surfaces, omit sealing coat.
When to use: Use above method for bonding new cement to tiled, bricked, granolithic and terrazzo floors. Also great for bonding concrete or plaster to asbestos, breeze-blocks, roofing felt, metal, wood, or for resurfacing spawled concrete.
Repairing concrete floors and stairs: Give sidewalks and patios a "tough-as-nails" quality, too. Make repairs up to 1" in thickness- Weldbond withstands trucking conditions. For a non-dust topping or repair: Prime surface with 1 part Weldbond, 5 parts water. Allow to dry. Working a small area at a time, coat base with 3 parts Weldbond and 1 part water. While surface is still tacky, cover it with a mortar of trowelling consistency. To make this, wet down 3 parts sand and 1 part cement with 1 part Weldbond and 10 parts water. Note: When finished, do not allow work to dry out quickly. Keep covered (damp) for at least 24 hours.
Dustproofing and sealing porous floors: For a seal that's 100% dustproof, thin 1 part Weldbond with 5 parts water. For heavy traffic areas; recoat as required. This method also prevents salt, gas and oil from attacking concrete driveways and sidewalks. On below-grade or garage floors, leave uncovered a 1 ft. strip along walls. This will act as a "breather strip" in the event there is moisture present under the floor.
Terrazzo, quarry and flagstones: Seal base of floor and tiles with 1 part Weldbond, 5 parts water and allow to dry. Before bedding tiles in sand and cement screed, give floor and backs of tiles a further coat of 3 parts Weldbond, 1 part water. While still tacky, apply sand and cement bedding to base and bed tiles. Bedding can be from 1/8" upwards.
Rendering, parging, or working with stucco: To render over bricks, terrazzo, tile, formed or pre-cast concrete, or stucco on structurally sound surfaces, prime surface with 1 part Weldbond mixed with 5 parts water. Allow to dry. Before covering surfaces with sand and cement, apply 3 parts Weldbond to 1 part water. Render up while still tacky.
For brick tuck pointing: Mix 1 part Weldbond with 5 parts water; add mortar. To ensure an even stronger bond, clean old mortar joints and soak in mixture of the 1 to 5 and proceed with the mortar mix.
For general concrete repairs: Seal surface if necessary. Allow to dry. Mix 1 part Weldbond with 1 part water. Stir this into sandmix cement to desired consistency and the mixture becomes an adhesive. Can be used to repair the edges of concrete stairways or porches, cracks in concrete floors or walls. To repair cracks, chisel them out in the form of an inverted "V" before sealing and trowelling in above mixture.