How To Open a Cartridge

How do you open a cartridge of Liquid Nails for a caulking gun?

Check the Liquid Nails Landscape specification

Selleys' product page and its dated technical sheet disagree on Landscape's chemistry, colour, paintability and pack size. Landscape figures below from the November 2020 technical sheet describe that document, not a confirmed specification for every current cartridge. Confirm the matching instructions before painting, choosing a colour, or relying on cure and loading times. See the source comparison and dated documents.

There are two cuts, and people usually only realise that after making a mess of the first one.

Cut one: the cartridge tip. On top of the cartridge there is a threaded section, and sitting above it a small cone-shaped tip. That cone is what you cut off. As long as you do not cut into the main threaded part, you will be fine — the thread is what the nozzle screws onto, and once it is gone the nozzle has nothing to hold it.

Cut two: the nozzle. Once the tip is off, screw on the supplied nozzle and trim it back to a suitable size to let the adhesive extrude easily. A reasonable opening is 3–5 mm in diameter. If the nozzle is not cut back far enough, you need excessive pressure to force the adhesive through a very small hole, which is hard work, hard to control, and hard on the gun.

What to cut with — and what not to

Use a sharp knife: a Stanley knife or a similar retracting-blade knife. Scissors are not suitable — they crush the cone rather than cutting it, and you end up tearing the top of the cartridge. And definitely do not use a hammer and nail.

Cut the nozzle at an angle where the product calls for it. Selleys' instructions for Auto Fix Instant Gasket, for instance, specify cutting the nozzle at 45°. An angled cut lets you hold the gun at a comfortable angle to the work while the opening still sits flat against the joint.

Sizing the opening for the job

The nozzle opening controls the bead, so match it to what you are doing rather than cutting the same size every time. Selleys' own published directions give useful reference points:

The rule that saves you is simple: start smaller than you think. You can always cut more off the nozzle, but you cannot put it back, and an oversized bead on a fine joint wastes product and makes a mess to tool.

Choosing a caulking gun

Not all guns are equal, and the difference shows up on thick products. Selleys' guidance for Roof & Gutter Silicone is to use a good-quality gun, and specifically a high-thrust-ratio caulking gun for high-viscosity products. If you find yourself squeezing hard on a 300 g cartridge of silicone and getting almost nothing out, the problem is more likely the gun than the nozzle.

How to run a good bead once it is open

  1. Make sure the surfaces are clean, dry and free of dust, oil and other contaminants before you start.
  2. Load the cartridge and take up the slack on the plunger before you get to the joint, so the first squeeze does not deliver a blob.
  3. Apply a continuous bead, keeping steady pressure and an even speed. Push the product into the joint rather than laying it on the surface.
  4. Tool sealants with a clean spatula dipped in soapy water before the skin forms. Skin times are short — Roof & Gutter Silicone skins in 5–10 minutes with a 5-minute tooling window.
  5. Release the gun's pressure at the end of the run, or the cartridge keeps extruding.

Whatever the product, take the time to read the pack directions before you use it. Application details, cure times and limitations vary between products in ways that are not obvious from the outside of the cartridge.

Storing a part-used cartridge

Once a cartridge is open, the clock is running. Selleys' storage guidance for its cartridge sealants is that opened packaging may skin and form a lump near the opening — discard any lumps or skin, then use the remaining product. Store unopened cartridges below 27 °C in a cool, dry place away from direct sunlight, and use within the shelf life on the pack; Roof & Gutter Silicone, for example, has an 18-month shelf life and is best used within 12 months of manufacture.

For the specifics of clearing a nozzle that has gone hard, see how to clean sealant left in the nozzle, and for keeping leftovers usable, how to store sealant.

Common questions about opening a cartridge

Where exactly do I cut?

Through the small cone-shaped section that sits on top of the threaded part. Do not cut any of the threaded part off.

What if I cut the thread off by mistake?

The nozzle can no longer be screwed on, so you lose control of the bead. There is no repair for this — it is why the advice is to cut carefully with a sharp blade rather than hack at it.

How big should the nozzle opening be?

3–5 mm in diameter is a reasonable general size. Match it to the joint, and start small.

Why is it so hard to squeeze out?

Usually one of three things: the nozzle is not cut back far enough, the cartridge tip has not actually been pierced, or the gun is not up to the viscosity of the product. Use a high-thrust-ratio gun for thick sealants.

Can I use scissors?

No. Scissors are not suitable, and you should definitely not use a hammer and nail.

Do I need to pierce a foil seal as well?

Some tubes and cartridges have an inner membrane. Follow the pack directions — the design varies between products, which is one more reason to read them before starting.

Is a sausage pack different?

Yes. Sausages are cut at the end and loaded into a sausage gun rather than screwed onto a nozzle — Selleys 650 FC comes in both a 300 mL cartridge and a 600 mL sausage, and its directions cover the sausage method.

How do I open a Selleys cartridge, such as Liquid Nails, for use in a caulking gun?

First, completely pierce the metal foil seal located inside the cartridge nipple so the product can flow when pressure is applied. Then cut the tip of the cartridge at a 45-degree angle (standard for most sealants and adhesives). Next, trim the nozzle to your desired bead size and screw it firmly onto the cartridge. Finally, insert the prepared cartridge into your caulking gun, making sure it is seated properly before beginning application.

What is the first step in preparing a cartridge before using a caulking gun?

The first step is to completely pierce the metal foil seal located inside the cartridge nipple, which allows the product to flow when pressure is applied by the caulking gun.

At what angle should I cut the tip of a Selleys cartridge?

For most sealants and adhesives, the tip of the cartridge should be cut at a 45-degree angle, which helps control the application. However, some products like Liquid Nails Heavy Duty may instead require a straight cut at a 5mm opening.

What nozzle opening sizes can I trim a cartridge to?

The nozzle can be trimmed to achieve different opening sizes ranging from 5mm to 20mm inner diameter, depending on your application requirements.

What should I do after trimming the cartridge nozzle to size?

Once trimmed to the correct size, screw the nozzle firmly onto the cartridge, then insert the prepared cartridge into your caulking gun, making sure it is seated properly before beginning application.

Does the cutting angle differ for all Selleys/Liquid Nails products?

No. While a 45-degree angle is standard for silicone-based sealants and most adhesives, some products like Liquid Nails Heavy Duty may use a straight cut at a 5mm opening instead.

What type of caulking gun is recommended for opening and using a cartridge?

A good-quality caulking gun is recommended for best results, especially for high-viscosity products where a high-thrust-ratio gun is beneficial.

Is there a time consideration after opening a cartridge?

Yes, once opened, cartridges should be used relatively quickly to prevent the product from skinning over.