This post will cover removing old silicone sealant. We will then demonstrate how to apply new sealant. The techniques described here can be used anywhere but kitchens and bathrooms are the most common places where sealant is applied.
MATERIALS & TOOLS REQUIRED
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Materials
*optional
Tools
- Cartridge gun
- Stanley blade
- Silicone applicator*
*optional
STEP 1: REMOVING OLD SILICONE SEALANT
There are two methods to remove old sealant. The first is to use a sealant remover. and the second is to scrape off the silicone manually.
Using silicone sealant remover
Sealant remover usually comes in a tube. You have to squeeze it all over the old silicone and leave it to stand for some time. After this, you can scrape off old silicone. Using a product like this, you will need to check and follow the instructions on the back of the tube.
There are some downsides to using these products:
- Cost: they tend to be expensive and you need a lot
- It doesn’t remove silicone in full: you will still need to manually scrape off residual silicone
- It’s messy: removing the silicone together with this product is quite a messy job
The upside is that there is less scraping involved. This is good if the surface you’ve got sealant on is prone to scratches.
Scraping off the sealant manually
If you don’t want to use silicone remover, you can just go ahead and scrape off the sealant manually. For this, you will need a sharp thin blade – a Stanley knife is perfect. First, run the blade along the top of the silicone, cutting it off the surface it’s adhered to.
Next, do the same along the bottom of the silicone.
You should now be able to pull the silicone strip off.
There will be some residue left after the previous step. Here is where the scraping comes in. Use your blade and gently but quickly scrape it back and forth across the surface. This will slowly remove the remainder of the silicone. It also helps to use your finger and rub the silicone patches – this rubs the silicone into loose clumps that you can just brush off. Make sure that you continue this process until there are no stray loose bits of silicone left.
STEP 2: APPLY NEW SEALANT
There are a few decisions to make before applying new sealant. Firstly, you need to decide whether you will be using masking tape or not. Masking tape is usually applied to make sure the sealant doesn’t ‘overspread’ during the application process. It is a good idea to use masking tape if you haven’t had a lot of experience applying sealant.
You will also need to decide whether you will use the sealant applicator or your finger. The applicator can be purchased from any DIY store and usually comes in a pack of a few. Each applicator will be designed to give a different bead size. Whether you use your finger or an applicator is completely up to you. Try out both if you’re not sure and see which you prefer.
Once decided how to proceed, apply masking tape if using it. It should be applied above and below the sealant line, leaving just enough space for a tidy thin bead. Note: if you’re applying silicone to a bath, fill the bath with water first. This stops the silicone from peeling after it dries due to the weight of the bath being much more when it’s full.
Make sure you have plenty of kitchen roll sheets handy and load up the cartridge gun with the silicone. Cut the tip off with a Stanley blade. Make sure to only cut a small hole – the larger the hole the bigger the bead of silicone will be.
Go ahead and run a bead of silicone along the join. Tips for getting a tidy bead:
- Do not lift the gun mid-bead. Try to go from one end to the other in one continuous move.
- Try to move the cartridge gun along at a constant speed.
- Try to apply a continuous amount of pressure to the gun trigger. If you need to release the trigger and press it again because the flow slows down, you will need to try and adjust your moving speed to the increased flow of silicone from the gun.
Once you have applied a bead, use your finger or the applicator to wipe off excess silicone. If you’ve not used masking tape, you can use white spirit to wipe off any silicone that spread out too much.
If you’ve used masking tape, make sure to lift it off before the silicone dries.
THE RESULT
The result should be a tidy line of fresh silicone. It should be just big enough to cover the join and spread a level amount above and below the join.
