Putty not skinning over.

[Doug71]

I have made a replacement sash for a customers sliding sash window which needs fitting Monday. I am meant to be fully painting the sash before it's fitted, I glazed it about 10 days ago but the putty is still too soft to paint. The sash has spent the last 3 days with a fan (not a fan heater, just a fan) pointed at it to hopefully speed things up but that doesn't seem to be having much effect. It's a typical 6 pane sash about 36" wide by 30" high, the glazing bars are very thin meaning the putty fillets are only small so I hoped it would have hardened off a bit by now.

Anyone got any tricks or tips that might help (don't say linseed oil paint, it has to be Dulux Weathershield).

Many thanks, Doug

 

[Trevanion]

I find that dusting the putty straight after glazing with powdered chalk makes a lot of difference in skinning over time, takes up some of the surface oils of the putty. A bit of heat would help but not too much as you could reverse what you're trying to achieve and the putty will just stay tacky.

I redid some putty on windows in April just before the scorcher summer and haven't got around to painting them yet. Even after 8 months, the putty has a very thin skin it and you could quite easily break it if you poked it too hard.

 

[woodcarver]

Make some beads out of wood =

 

[Trevanion]

Make some beads out of wood =

On some listed buildings they only allow putty and you can (rarely) get in trouble by not following guidelines. Plus I don’t think he fancies ripping all the putty back out.

 

[mrpercysnodgrass]

I had this problem several years ago. I got some Terebine driers and kneaded it into the putty (a messy job ) which speeded up the drying process a lot , that would of course require you to take the putty out and re-apply.
I have always found that cold temperatures make the putty go off quicker!

 

[Jacob]

Spray it with water mist and leave to dry. Speeds up hardening and also makes it easier to clean off smears from the glass.
Painting before fitting is a really bad idea. Not only having to get it dry enough to handle but also to avoid marking it in the fitting process - not least because you might have to make some little adjustments after it's gone in.
A coat of primer is enough. Much easier to paint after fitting when the putty has gone off and you can touch up any blemishes its picked up in the process.

 

[Doug71]

Thanks for the advice.

I would rather the sash be painted after but it's for a prominent listed building in my village and they want it back to normal asap, plus it's obviously not the time of year for external painting now.

I did fully fit the sash before glazing so hopefully it should go in without too much trouble.

I have moved the sash into my workshop where it's cooler to hopefully speed things up.

Thank you for the water tip Jacob, I will give it a try.

Doug

 

[John Brown]

I've twice used the nasty acrylic "putty" for this very reason. Obviously better to use real putty and wait, then paint in situ, but these particular windows are impossible to reach from outside without extensive scaffolding, so sometimes you have to cheat a bit.
I realise this is no help...