Mastic vs Silicone?

[bradycg]

I have just had a window frame fitted to a garage. I have a few gaps around the outside of the existing wooden door frame, and around the inside of the window (in the wall brickwork, not directly related to the window installation.

I bought from my local DIY centre some Evo-Stik "Frame mastic". On the tube it does say "overpaintable", so I assumed that it would skin and cure. However after 72 hours it is still soft and wet/sticky to the touch, and comes off on skin/clothes.

I went onto the Bostik (parent company) website, and this particular Evo-Stik product is not even listed. I have sent an email asking about it.

So, NOW I am thinking about this.
- what is the difference between Mastic and Sealant (eg silicone based)
- should I expect "Mastic" to skin ?
- perhaps I could have used some form of "cement" or exterior polyfilla, but I wanted something I could "inject" with a gun, into deep voids.
Would a "caulk" have been better? Are any suitable for exterior use?
I wanted to improive the security as well as sealing gaps.

I suspect I might need to dig out the mastic and start again (as best I can).
Fortunately it is a garage and not a main room.

 

[noseall]

True 'mastic' as i understand it is an oil based formula that does take time to skin (particularly in cold weather) and is paintable. I would not be alarmed at the fact that it is still sticky.

Even after a decade and a half good mastic is still pliable beneath the skin.