Adhesive and Sealant Applications & Tools
Experts in the tools used for specific applications. The tool may cost you very little, but it accounts for over 50% of the success in the application.
Wednesday, October 12, 2011
Grouting and Pointing
Many bulk caulk guns can be used to dispense grout and mortar. 20 oz capacity guns seem to be the most popular for this application, but larger and smaller guns work equally well--just consider the weight. The barrels on these guns measure 14" x 2". A standard 1/2" ID metal nozzle allows for precise placement of mortar between the stone or brick and clean up with water is minimal.
The standard metal nozzle can be replaced with other metal nozzles as small as 1/8" or as large as 3/4". Alternatively, substitute a cone-shaped nozzle and trim the opening to any size up to 1 3/4". The tapered shape of the cone will result in less back pressure compared to a straight metal nozzle.
To load the gun, remove the front cap, pull the rod completely back and load the barrel by troweling in your mix. Some polymer modified products can be loaded by sucking them up into the barrel, the same way you do with caulk. The finer the aggregate in the mortar or grout, the easier it will be to dispense.
Tap the side of the barrel frequently during loading to remove voids. Wipe the barrel and cap threads clean before replacing the cap. You may need to modify your mix slightly for dispensing by gun; a wetter mix flows better, but too wet and you can get separation of the water and aggregate inside the barrel. The addition of a latex masonry additive (know in the trade as "milk") will also make dispensing easier and help keep the mix together. Some users have reported similar benefits from the addition of liquid dish soap to the mix. Clean the gun after use with water. Periodically disassemble the leather pistons to clean and re-oil the pistons (use standard motor oil or mineral oil) and barrel to maintain a tight seal. If you are doing a large quantity of pointing and the leather pistons require frequent maintenance consider replacing the front one with a nitrile or neoprene rubber piston.
The standard metal nozzle can be replaced with other metal nozzles as small as 1/8" or as large as 3/4". Alternatively, substitute a cone-shaped nozzle and trim the opening to any size up to 1 3/4". The tapered shape of the cone will result in less back pressure compared to a straight metal nozzle.
To load the gun, remove the front cap, pull the rod completely back and load the barrel by troweling in your mix. Some polymer modified products can be loaded by sucking them up into the barrel, the same way you do with caulk. The finer the aggregate in the mortar or grout, the easier it will be to dispense.
Tap the side of the barrel frequently during loading to remove voids. Wipe the barrel and cap threads clean before replacing the cap. You may need to modify your mix slightly for dispensing by gun; a wetter mix flows better, but too wet and you can get separation of the water and aggregate inside the barrel. The addition of a latex masonry additive (know in the trade as "milk") will also make dispensing easier and help keep the mix together. Some users have reported similar benefits from the addition of liquid dish soap to the mix. Clean the gun after use with water. Periodically disassemble the leather pistons to clean and re-oil the pistons (use standard motor oil or mineral oil) and barrel to maintain a tight seal. If you are doing a large quantity of pointing and the leather pistons require frequent maintenance consider replacing the front one with a nitrile or neoprene rubber piston.
Labels: bulk guns, grouting, pointing
