Merlex Stucco Keeping it Premium since 1963



  Hydro Plug
  One-Component Quick Setting Hydraulic Cement For stopping running water leaks
  Hand or trowel applied.
  Merlex Hydro Plug is quick setting, hydraulic cement repair mortar which instantly stops running water or seepage leaks in concrete and masonry walls and floors. The Hydro Plug formulation expands as it sets, is non-shrinking, and gains strength when subjected to constant water pressure. Hydro Plug may be applied under water.
  • Permanently stops water leaks.
  • Mixes easily with potable water.
  • Simple application.
  • Non-corrosive, non-shrinking, non-metallic.
  • Eliminates further water damage.
  • Environmentally safe.
  • VOC compliant.
  Suitable for interior or exterior applications, above or below grade.
  Hydro Plug is effective on new and existing portland cement including stucco, concrete and masonry surfaces.
Examples of Use
  Recommended uses include swimming pools, spas, fountains, elevator pits, dams, block walls, precast panels, tilt-up construction, reservoirs, water tanks, wells, mines, foundations, cisterns, tunnels, sewers, and other structures subject to leakage. Hydro Plug will seal cracks at the junction of floors and walls.
and Storage
  Hydro Plug is available in 10 lb. (4.54 kg) cans, 4 per carton, and in 50 lb. (22.68 kg) pails. Hydro Plug must be kept in dry storage area. Shelf life is one year properly stored.
  One pound of Hydro Plug yields approximately 17 cubic inches (280 cc) and will repair 30 inches (76 cm) of 3/4" (1.9 cm) crack.
Surface Preparation

The area surrounding the hole or crack should be opened with a chisel to a minimum depth and width of 3/4". To insure good mechanical bond and to allow for proper curing, undercut the crack or hole so the bottom of the repair area is wider than the top. Areas to be patched must be structurally sound, clean, free of dust, dirt, loose particles, silicones, paint products, efflorescence or any other foreign substance which could impair the natural bond.

  One quart of water mixes 10 pounds (4.54 kg) of Hydro Plug. For smaller batches, use 3 to 4 ounces (90 to 120 ml) of water per pound of Hydro Plug. Pour water into a clean mixing container and gradually add the proper amount of Hydro Plug. Mix rapidly for approximately 30 to 60 seconds to achieve a consistency of a heavy pancake batter. Material will begin to gel in approximately 2 to 3 minutes. Caution: Hydro Plug is a fast setting material which can be applied immediately. To prevent flash setting of Hydro Plug during periods of hot/dry weather, use ice cold water for mixing. Do not re-temper.

If the areas to be repaired are dry, they should be predampened to control suction. If possible, absorb any standing or running water.

General Patching: Apply Hydro Plug by hand or with a trowel, forcing material firmly into repair area. Immediately fill to the full depth of the opening and then shave and feather edge to conform to surrounding surfaces.

Patching Active Leaks: Starting at the top, force Hydro Plug into the crack or hole to the full depth. Apply pressure to the patched area until the Hydro Plug has taken a firm set. Continue patching towards the area with the greatest pressure. When extreme water pressure is encountered, hold the mixed Hydro Plug in the hand until it becomes warm. Then rapidly force the patch into the hole, and apply continuous pressure until the Hydro Plug has set, and the water has stopped running. Conform to surrounding surfaces. Caution: Do not use a twisting motion when applying Hydro Plug.

Clean Up
  After completing work, clean all mixing equipment and application tools immediately with water. During application, protect floors and surrounding areas from spills and splatters.
  When forcing Hydro Plug into a crack or hole, never use a twisting motion. Do not apply to frozen or frost filled areas. During periods of hot dry weather, Hydro Plug should be mixed with ice water to increase working time. In cold weather, mix Hydro Plug with warm water and pre-heat areas to be patched with a blow torch. Do not predampen in cold weather.
  Hydro Plug Quick Setting Hydraulic Cement is warranted to perform in accordance with the product specification when used according to application instructions on the label. This warranty is limited and shall not exceed the total amount paid by the buyer for the product. In no event will Merlex Stucco, Inc. be liable for loss of profits, special or consequential damages in respect to any claim. The foregoing warranties are in lieu of all other warranties express or implied including those concerning fitness for a particular use.
Environmental & Safety
  Hydro Plug contains portland cement and is alkaline on contact with water. May be irritating to eyes and skin. Wear appropriate dust, skin, and eye protection. In case of eye contact, flush immediately with water, consult physician. Wash hands with soap and water after use and before eating. Keep out of reach of children.
Technical Data
Compressive Strength ASTM C-109 20 minutes: 2160 psi
24 hours: 6330 psi
7 day: 7070 psi
28 day: 8630 psi