Sealant gun buying guide

Manual sealant guns work using a basic rod mechanism. They don't require any power meaning you won't get caught out halfway through caulking the bath! The simplicity of this design means that these guns are very reliable. What's more, they are inexpensive and strong.

But there are downsides to these tools. In terms of application, a certain amount of dexterity is required if you want to lay an even bead. The amount of silicone that comes out and the consistency with which it is applied depends on the pressure you exert on the gun – if you don't apply even pressure, your silicone won't be even either! It can also be tricky to apply the correct amount of product.

When temperatures are low, the glue or silicone will harden slightly meaning you will have to push a bit harder. If you go for a low-end sealant gun and apply too much pressure, the frame will bend before your silicone comes out so don't try to scrimp on quality! If you are having trouble getting the silicone out, try warming up the product first rather than breaking your sealant gun and straining your wrist in the process!

Cordless caulking guns can be summed up in three words: accuracy, economy and comfort!

Even application

If you want a bead that's the same diameter all the way along, you will have to apply the silicone with even pressure. Too little pressure and you'll end up with a skinny line; too much and you'll end up with bulges of silicone. Electric sealant guns help to prevent these issues by releasing a continuous flow of product.

No product wastage

If you have a precise gluing task to carry out or just a small bead of silicone to apply, you'll only need a small amount of product. Cordless caulking guns usually allow you to adjust the flow rate of the gun meaning you can control the amount of glue or silicone that comes out. This means you won't end up applying too much or too little product!

Enhanced user comfort 

If you have a lot of caulking to do or you just have weak wrists, a cordless sealant gun is ideal! These guns can come with a number of features such as:

• trigger locking;
• a built-in poker to unblock cartridges;
• dripless application;
• battery indicator.

There are three different types of batteries.

Nickel cadmium (Ni-cd) batteries

Nickel cadmium batteries are the oldest batteries on the market. These batteries are heavy and usually take forever to charge.  They also have a memory effect which means that if the battery is not sufficiently discharged before you attempt to recharge, the battery will fix a lower point of charge as its maximum level the next time it's plugged in. Over time, the battery will struggle to hold a charge. Nickel cadmium batteries are generally used for low-end power tools and are gradually being replaced by lithium-ion batteries. It is recommended to allow Ni-cd batteries to discharge fully before recharging. You should also ensure that you don't leave them on the charger once they are fully charged. These batteries can withstand a high number of charge cycles.

Lithium-ion (Li-ion) batteries

These are the batteries to look for! They are lightweight, quick charging (an hour and a half on average) and do not have a memory effect. This means that the battery will give out all the power it can – or just about! – until the power runs out. However, you can get cut short if your tool doesn't have a battery indicator. Generally speaking, lithium batteries are used for most power tools as they offer the greatest user comfort.

Nickel metal hydride (Ni-MH) batteries

Nickel metal hydride Nickel metal hydride batteries are fairly heavy (heavier than a Ni-cd battery, for example) but don't have a memory effect. However, their cycle life is about three times lower than Ni-cd batteries.

Standard sealant guns are usually designed to hold cartridges of 320 ml. Depending on the model you choose, your caulking gun may be able to hold different types of cartridges. Here are the most popular cartridge sizes: 

• 310 ml;
• 380 ml;
• 400 ml;
• 540 ml;
• 600 ml.

The volume of the cartridge dictates the capacity of the gun. 

So be sure to check the volume of the cartridges you need to use before buying a sealant gun. As the frame size can vary from model to model, if you're not careful, you may end up with a gun that doesn't match your needs.

1. Your choice of sealant gun, as with any tool, depends on your own needs and expectations.
2. Electric sealant guns are more accurate and for this reason alone, are best if you have more demanding tasks to perform.
3. If, on the other hand, you only have some rough gluing to do, you're prepared to smooth out your silicone with your finger and you only go through a cartridge or two a week, a strong manual sealant gun will work fine. What's more, the gun will probably survive a fall off a roof!
4. Bear in mind that cordless sealant guns are power tools in themselves and need to be connected to a battery. These tools are also more fragile and will be a more tempting prospect to thieves on a building site!
5. Manual sealant guns also have a lot of advantages: they are less expensive, durable and you'll build some serious arm muscles using one on a regular basis!

One final tip: after use, allow a small amount of silicone to come out of the nozzle so you can simply pull off the dry silicone later rather than having to unblock the nozzle with a poker.