Is silicone an adhesive? Question

[JustMe]

So I'm building a canister filter I mentioned a while back, and I'm running into problems with leaks. I'm trying to glue plastic (like the plastic used in Tupperware), and vinyl tubing. There's a hole I drilled into the plastic, and I need to make an airtight, waterproof seal for the hole.

Would silicone actually form a strong bond between the tube and the plastic? Or would it just form a weak waterproof seal? I need the bond to hold.

I see a lot of people who do DIY projects using silicone, and apparently it works perfectly, but it seems...messy. The seal always seems like there's an excess of silicone splattered all over the tubing. I'm just worried if the silicone would actually GLUE the two pieces together.

If there's a better way to make a strong, waterproof seal (couplings, hot glue, other materials, etc.), please let me know. Thanks much.

 

[leeishom]

Silicon or caulk is a sealant more than a adhesive.
That's why it's easy to remove.
I would use a proper adhesive and then use caulk to seal
and protect the adhesive.

 

[JustMe]

What would be a proper adhesive?

 

[ryanr]

Now this is an area I have a fair bit of experience in

The adhesive properties vary depending on the material you're trying to bond. e.g. PVC glue is great for balsa wood, but doesn't work on plastics.

Silicone, by nature, forms a nice flexible gasket when it goes off.

My approach would be to have the tube slightly larger than the hole, so that it compresses slightly and the elastic properties expand out to create a seal. Then apply silicone to the two sides of the 'seal' to make it water tight.

Many model building [ships/planes etc] hobby shops sell model glue that kind of 'melts' the two plastic surfaces to be bonded so that they then kind of mould together, and then the glue goes off.
[edit:] This is a similar to process to the way metals are welded together. The glue helps to weld the plastic together and then locks it in place when the glue settles/goes off.

Products such as Araldite and other 2 part epoxy resins are great for plastics. Some contact adhesives may also work. I imagine that most hardware/Walmarts would probably stock a wide range of adhesives. I'd just read the labels looking for ones designed for plastic/vinyl.

HTH.