Adhesive and Sealant Applications & Tools

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. 

Labels: bulk guns, grouting, pointing

This is a quick video showing the insertion of backer rod, loading a bulk gun, and applying the sealant. Note:
1. The backer rod tool places the backer rod at a fixed depth and inserts the backer rod quickly. (This is a bit of an ideal joint, most joints are not a fixed width with nice edges, but this tool does improve the installation of backer rod.)
2. Putting a slight film of oil will help keep the material from sticking to the outside of the barrel.
3. Cordless provides a smooth continuous flow of material. (This applicator is running the tool a bit on the slow side, he could easily have doubled his speed. I guess that is the difference between an Engineer and someone who seals joints for a living.... the Engineer is too careful and slow.)

Labels: backer rods, bulk guns, joints, videos

We have discussed loading a Bulk Gun....now if the inside of the barrel was coated with Teflon® what would happen? Material won't stick to the barrel and it would remain cleaner and be easier to clean.... AND it would be reduce the friction between the piston and the barrel which
A. Makes it easier to load.
B. Makes it easier to dispense and also dispense a smooth long bead of sealant. Think about it, the hand is a pump so every time you go to grab a new grip with the trigger you create a divot and glob in your bead. Well with the smooth rod and barrels with Teflon® industrial coating it is easier to reduce the divot.

At the World of Concrete last year we had an outside booth where Albion and a number of material manufacturers (Sika, Tremco, Pecora, and BASF) did live demonstrations with Teflon® coated Bulk Guns. My Engineering team who assisted and worked that booth had to clean the guns every night. Their response after dispensing ALL day was..... boy, does Teflon® coated ID barrels make a big difference!

Maybe we will see you this year at the World of Concrete. If so, make sure you visit our outside booth and see how easy it is to dispense material using a bulk gun.

Labels: barrels, bulk guns, Teflon, World of Concrete