Silicone release agent?

[GMM]

At work, they've been draught-proofing the old windows. It seem that this has involved squirting a big bead of silicone along each mating surface, then closing the window until it goes off. Good (if temporary-feeling) idea for some locations as it moulds to the right shape. Once cured, the silicone stays on the one face.

They didn't do my area, so no chance to find out how it was done, but they must have used some release agent on the 'uncoated' face for this to work.

Any idea what they might have used as a release agent?

[Dave Liquorice]

I've heard that cling film is good but not tried it.

[Baz]

Washing Up Liquid.

[stuart noble]

Yes, or vaseline

[polygonum]

involved squirting a big

goes off. Good (if

Once cured, the silicone stays

must have used some release

When I saw something like this done, they put tape down one surface (e.g. insulating tape), squirted silicone down the other face, and closed for a few hours. Opened the windows, removed the tape.

The windows were metal casements, and I think they put tape on the frame itself and silicone onto the opening window. It did not work very well simply because the frames were dirty and paint somewhat flaking before they started - and that was not properly addressed.

[The Medway Handyman]

involved squirting a big

goes off. Good (if

Once cured, the silicone stays

must have used some release

Sounds daft, but silicone is used as a mould release agent.

I can never work out how come silicone sealant is so sticky when silicone spray is so slippery?

[Old Git]

Works a treat. My father refused to buy new windows, saying, "They will outlast me" Turned out he was right on that score. I had to stay in his house for nearly a year and got pissed off with watching the curtains billow out at 90deg and freezing to death.

Waited for a reasonably mild day and started early morning. Wrapped the edges of the opening windows with cling film, put a bead of silicone around the frames, closed the windows to almost shut and left them like that for the rest of the day. When the silicone was about set, off with the cling film and they worked a treat.

[GMM]

This sounds like a cue for an experiment(!) Sure I have an open tube of silicone in the garage (I normally do) so I'll see who well either works ....

[GMM]

has involved squirting a big

goes off. Good (if

Once cured, the silicone stays

must have used some release

Very true Dave: The spray must be mostly slippery at first because it's in a solvent: Maybe they used the spray (or just the solvent) as the release agent..A third arm to the experiment there .....

[GMM]

I've found cling film pretty useful when using wood filler on an edge too: Cover a piece of timber/board/whatever in cling film, clamp to an edge, stuff the filler into the gap, then peel off, leaving a straight finish.

[The Natural Philosopher]

involved squirting a big

goes off. Good (if

Once cured, the silicone stays

must have used some release

Oddly enough, 'silicone spray lubricant'..

[The Natural Philosopher]

That is well worth knowing.

[The Natural Philosopher]

silicone is a term used for may different things

All it really means is 'an organic compound containing silicon atoms'

[charles]

Is that "organic" as in "no chemicals have been used in growing this" ?

[The Natural Philosopher]

No. that's 'organic as in also containing carbon atoms and hydrogen ones'

[charles]

you mean the proper scientific definition.

[Dave Liquorice]

Think I'd much rather use a excess of physical barrier (aka cling film) rather than spray stuff that might be a bit patchy. It wouldn't take much not to release to have the window siliconed shut and working out where that was to slice it through with a blade could be a right begger...

[GMM]

I think I'm with you Dave, although there's always a case for empirical evaluation(!) so I'll try to have a go at some of the suggestions here and see what works best. Clearly it would be a lot simpler to just seal things shut, but that might not be too useful for a door, for example (!)

In principle, it could be a useful way to draught proof an irregular gap that's not suitable for a weather strip, though I suspect it would need a bit of ongoing maintenance. I was thinking mostly about temporary measures in some draughty places (I have plenty) pending doing a proper job.

[newshound]

It's all down to chemistry. The air cure stuff as used in sealant cartridges and which smells of vinegar sticks to almost everything when it sets. The two-pack stuff (RTV, short for room temperature vulcanisation) doesn't stick to anything, hence is used for things like dental moulding. Silicone oils are not particularly good lubricants for metals (compared to mineral oils) but are very good on most plastics.

[Weatherlawyer]

valuation(!) so I'll try to have a

would be a lot simpler to just

that's not suitable for a weather

was thinking mostly about

Scrape both mating surfaces. There is a primer for the side that is to get the silicon but I am not sure it is needed. (pretty sure it is expensive though.) Apply non stick washing up liquid grease or whatever. Run bead of clear silicon down rebate. Close window. If you have a choice of closures use the sightly open notch on the lever. Next day give the casement a judicial going over. If it is too fast, inset thin blade along joint.