It's a stiff-but-flexible rubber. NOT hard plastic. It NEEDS to have some flexibility to work - it makes a perfect contact with the surfaces you are siliconing.
You can see how the outside edges taper? This provides the right amount of flexibility to make perfect contact with imperfect surfaces, and ensures the tool seals tightly along these surfaces as it's pulled along, giving the sili bead a sharp edge and leaving no residue on the surfaces. This wouldn't work without some flexibility.
A wee tip: if you are, say, doing a long run like a bath-to-splashback seal, and mess up halfway along (or find you didn't apply enough sili so there's dips or gaps there), don't panic. Just carry on tooling that run, fill in any gaps with a little more sili, place the tool back before you get to the 'messed up bits, hold it LIGHTLY in place, NOT pressing down firmly, and start pulling it along again - you will likely find that it's not actually touching the nice bead you've just formed with it. Now, as you approach the newly-filled-messed-up bits, start to press the tool a little more firmly against both surfaces (eg the bath and tiles) until the tooling edge makes gentle contact with the pre-formed sili bead as you are still moving the tool, and it should 'land' without making a ripple and then go on to smooth out the bits you messed up the first time!
Ie, you can control how much contact you make by pressing the tool gently or more firmly against the surfaces.
Answered by: DevsAd
Date published: 2021-10-28
