Skeleton Gun also known as a caulking gun and mastic gun

What is Skeleton Gun

Skeleton Gun is a tool but dispenses different materials from a tube-like, adhesives, sealants and caulk.

Cartridges coming sizes from 310ml up to 900ml cartridges.

A Skeleton Gun often referred to as mastic, caulking guns or caulk guns and come in different shapes and sizes depending on the work what needs to be carried out.

For example, for internal sanitary work, a contractor may wish to use cartridges from 290ml-310ml with this size it is easier to get behind taps and awkward angles.

The contractor who mostly on external work like expansion joints in walls and floors etc. will be using larger packaged materials, either 380-400ml cartridges or foil pack Skeleton gun.

This gun is designed for use with foil packs 400-600ml, the foil packs are enclosed aluminium barrel can also be used for standard cartridges also known as a Sausage Gun

Thrust Ratio

Thrust ratio measures the force applied on the Plunger Arm with each trigger pull.

Just like there are many types of skeleton guns you also have different types of Thrust Ratio dependent on the type of material you wish to use.

In general the thicker the material the higher the ratio for example cartridges with products containing epoxies, polyurethanes and some hybrid polymers commanding the higher ratios guns, anywhere from 18:1 thrust ratio to 26:1 thrust ratio.

when using caulking material a typical skeleton guns run from a low of 3:1 thrust ratio up to 18:1 thrust ratio.

Professional Guns = Approximately 12:1 extrusion ratio
Skeleton Guns = Approximately 7:1 extrusion ratio
Barrel Guns = Approximately 18:1 extrusion ratio
Resin Guns/Dual Cartridge Guns = Approximately 16:1 – 26:1 extrusion ratio

Tools and Equipment

How to prepare cartridge or Foil Pack for skeleton gun

1. Make sure you have the right thrust ratio skeleton gun for the cartridge you going to be using.

2. Using a Trimming Knife or perfectly Cartridge Knife, cut the nozzle close to the top at 45°.

3. Trim the nozzle on both sides of the hole approximately 45° forming a 90° angle so the nozzle will fit into the corner squarely, you can refind the shape by rubbing the tip of the nozzle in the corner backwards and forwards

4. The top of the nozzle needs to be trimmed off leaving a smooth tip nozzle.

5. Cartridge Knife can be used to remove the top of the cartridge which is just above the screw thread, then screw the nozzle onto the cartridge.

If you are using a trimming knife to perform the above make sure that you are always cutting away from yourself and you have the correct PPE, like Cut Resistant Safety Gloves.

Using a Trimming Knife

Using a Cartridge Knife

Components of a Skeleton Gun

Skeleton gun opening rod is used to make holes in foil packs and also be used to clear the nozzle.

If the opening rod is larger than the opening on the nozzle, then use thinner wire like a paperclip opened up.

The trigger release lever has two functions one is to keep the plunger arm in place under tension for continuous flow of the material.

When pressing the trigger release lever it will stop the flow of sealant or caulking during the application, plus it releases the plunger arm enabling you to put it fully to the rear by the plunger arm hook.

It is a good idea to spray or oil the working parts to keep your skeleton gunning good working order

Loading a cartridge for skeleton gun

Prepare the skeleton gun by pressing on the trigger release lever and pulling back on the plunger arm hook so that the plunger is to the rear.

Insert cartridge inside the applicator frame then press on the trigger release lever and pushing the plunger arm so that the plunger fits inside the cartridge.

Place paper or newspaper onto the worktop then press the trigger until the material inside the cartridge starts coming out of the nozzle, make sure that you have no air bubbles otherwise you will not be able to caulk a continuous bead.

Components of a Foil Pack Skeleton Gun

The foil pack skeleton gun has got the same basic components as a skeleton gun the only difference is instead of an applicator frame it is got aluminium barrel with two end caps holding a foil pack, and you need a separate nozzle.

How to load Foil Pack Skeleton Gun

Cut the nozzle at 45° to the desired width, then trim the nozzle on both sides of the hole approximately 45° forming a 90° angle so the nozzle will fit into the corner squarely, you can refind the shape by rubbing the tip of the nozzle in the corner backwards and forwards.

Unscrew the Front Cap from the aluminium barrel, pressing on the trigger release lever and pulling back on the plunger arm so that the plunger is to the rear.

This Placed foil pack inside the aluminium barrel, squeeze the trigger until the foil pack is flush with the aluminium barrel.

Cutting the Foil Pack in one or two places with a utility knife, the pack will open up when you apply pressure to the plunging arm.

Place of the nozzle Inside the Front Cap then screw the Front Cap back on.

Pressing the Trigger until the material inside the cartridge starts coming out of the nozzle, make sure that you have no air bubbles otherwise you will not be able to caulk a continuous bead

Removing Cartridge from the Applicator Frame

To release the cartridge from the applicator frame simply hold the handle and with your thumb press down on the trigger release lever with your other hand pull on the hook on the plunger arm so the plunger is completely out of the cartridge tube.

Simply remove the cartridge from the applicator frame and dispose of contents and container in accordance with the manufacturer’s instructions.

Removing Foil Pack from the Aluminium Barrel

Unscrew the Front Cap from the aluminium barrel, then remove the foil pack and dispose of contents in accordance with the manufacturer’s instructions.

This is a good time to strip down the Foil pack Skeleton gun to its basic components and clean all parts with the recommended cleaning solution