Let me start by apologizing for the quality of the images in this instructable, they were taken in my van as this was a true bush build, but I would never let something like that get in the way of making an instuctable.
I did this as I had a massive amount of Tec 7 to apply to a job (6 full cartridges in the end) and I wanted a powered way to pump them. Anyone who has ever dispensed even one full cartridge in one sitting will know the pain of that much pumping!
Step 1: Getting Started
You will need:
1 cordless drill (with additional handle)
1 Caulk Gun
1 or more tubes of caulk, glue, adhesive, etc
1 Length of 6mm threaded bar
Some nuts & bolts
Some basic hand tools
Step 2: Prep the Gun and the Handle
I didn't get the first image but this gun had the cup on the front of the push arm bolted on, I removed the nut and withdrew the arm. At this point springs flew everywhere!
I had to drill out a hole in the spare front handle for my drill, it was originally for the depth stop but in 4 years owning this drill I have never used the handle or depth stop. I inserted the old push rod I had just removed from the gun, this will be used as a guide and stabilizer arm.
I passed the 6mm threaded bar in through the hole in the back of the caulk gun (where the push rod used to protrude) and bolted on the cup that ultimately pushes the plunger in the back of the cartridge.
I ran an M6 nut down the rod from the back and retained it with part of the gun frame I bent. This later proved to be too little and I had to add a tek screw as an additional stop for the nut. This nut becomes the anchor point that the threaded bar will run in and out of.
Step 3: Fit the Handle & Guide
I fit the handle to the drill and locked in place as normal.
I clamped the threaded bar in the chuck and then use the end of the push rod to mark its position on the read of the handle on the caulk gun.
I then drilled the handle and passed the push rod through and fixed a nut.
The push rod can slide back and forth as the lead screw runs in and out and it being locked to both the drill and the caulk gun, stops the caulk gun spinning round when you run the drill.
Step 4: Built
This is the finished assembly. It is quite unwieldy when you insert a fresh cartridge as it is quite long, but as you run down, the distance between the drill and the gun shortens and everything becomes more stable.
The advantages are:
- You don't have to pump
- You can control the speed of the dispensation
- You get a constant, smooth bead
I made a video when I got home, sorry again about the quality, I had nobody to hold the camera.
The bead is a little shaky as I dropped the assembly while fitting a cartridge and bent the lead screw a little, it still runs but the bead is not as good.