How To Use An Expanding Foam Gun

Contents:

• Key takeaways
• How to use an expanding foam gun
• Helpful tips for better results
• How to clean & maintain the gun
• Common mistakes to avoid
• FAQs

An expanding foam gun is a tool used to apply polyurethane foam neatly and with better control. They are commonly used for sealing gaps around doors and windows, to help prevent heat loss and reduce cold air from coming into your home. They are also great for tight, hard to reach spaces, such as cables and pipes.

The gun works by securing onto the foam can and allows you to apply it accurately using the trigger. The gun trigger allows you to adjust how much foam comes out of the gun which helps to apply foam accurately into gaps, joints and cavities with a cleaner finish.

Using a foam gun is a cost effective solution, compared to a disposable applicator as you can reuse it and it creates a neater result making it ideal for DIY projects and construction work.

In this guide we will explain how to use an expanding foam gun, helpful tips for better results, how to maintain the gun and common mistakes to avoid.

Preparation: Clean the area that you are working on and make sure it is dust free before use.

Application: Position the gun upside down and maintain a consistent pressure for a smooth and controlled flow.

Time: To get a clean and solid finish, let the foam completely cure before trimming. Some products can be trimmed after one hour, but it can take up to 24 hours to fully cure.

Maintenance: To avoid hardened foam from obstructing the nozzle, always clean the gun after use.

Before using your expanding foam gun make sure that you are wearing the appropriate clothing, such as gloves and eye protection (if suitable).

Step 1: Prepare and clean the surface – make sure that there is no dust or dirt to improve adhesion of the expanding foam.

Step 2: Shake the foam can thoroughly – to ensure that the two main components are mixed.

Step 3: Attach the can properly to the gun – to make sure that you prevent leaks and have a controlled application. 

Step 4: Hold the foam gun upside down – which will allow you to dispose the foam evenly and allow you to have better control. 

Step 5: Apply slowly and with care – this will avoid overfilling gaps and let the foam expand significantly. 

These are the things you should consider for better results:

Testing the foam flow – find a small area to test the expanding foam gun to make sure that the gun is working properly before starting the main job.

Assess the area – to see if you will need to adjust the flow depending on the size of the gap. 

Apply the foam slowly – to avoid overfilling and for better accuracy. 

Give the foam time to dry – after applying it before touching it or trimming it as this can deform it, make it sticky and it may prevent bonding. Read our guide on how long expanding foam takes you dry for further advice.

To give the professional expanding foam gun a longer lifespan you need to make sure that you clean the gun. After you finish the job and you still have foam left over you should leave the can in the gun and use a wipe to clean the nozzle. If you remove it and the can is half full, air will get into the gun which will cause the foam to harden inside. However, if the can is empty you should remove it from the gun, dispose of the can and clean the gun.

For deeper cleaning you should use an expanding foam gun cleaner or a solvent to remove any uncured residue. You should then store the expanding foam gun upright and in a room that is cool and dry to prevent any rust from getting to it. You should always check the gun before using it to see if there are any buildups to ensure smooth and precise application every time you use the gun.

Below are some common mistakes that you should avoid when using the expanding foam gun.

• Releasing too much foam – foam expands after application and this can lead to overfilling, mess and even damage or distortion to the surrounding area.

• Not securing the can properly to the gun – this can cause foam leakage and allow air to enter, which can affect the guns performance - resulting in poor flow.

• Dragging the tip – it is important to not do this as you are at risk of the gun leaking and if the tip is damaged the foam can harden inside of the gun and block it permanently.

• Not cleaning the gun – the foam can harden inside, and you are at risk of the gun clogging which can make it unusable.