Putty and paint advice for sash windows

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markturner

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I know several threads exist on here and have looked at most. I have a specific query regarding the sashes I am currently making and installing. They were glazed using trad putty 2 weeks ago, stored in the house & workshop for painting. I am told by the glazer we can paint after 2 weeks, but the putty is still pretty soft and you have to be very careful not to deform it when brushing....its not dragging though.

I am under a fair bit of pressure from teh client to install the sashes ( frames already fitted and windows blocked off with OSB) but we wanted to hold off and paint the sashes on the bench before fitting as its easier to get a better job that way and we dont have to battle the weather.

If we do end up having to install the sashes with the putty ( we have painted the wood) unpainted, will this cause any issues to teh putty's drying process or give problems down the line? Thinking maybe fit the sashes and pop them out again when teh putty is drier....?

Using ( at clients insistence) Farrow and ball water based exterior paint.

Thanks
 
Linseed putty hardens with oxygen so increasing air flow around the putty might increase the hardening rate somewhat.
 
As said air flow will help, a fan blowing over them should speed things up.

Water based paint and linseed oil putty don't always play well together.........
 
I painted some trad putty almost immediately in the summer and it was too early so the paint cracked and flaked off, however a few months later a light sand and touchup on the putty and it all was good. Offer fair warning to the client that you can install sooner with the risk of some future touch-ups.
 
I know several threads exist on here and have looked at most. I have a specific query regarding the sashes I am currently making and installing. They were glazed using trad putty 2 weeks ago, stored in the house & workshop for painting. I am told by the glazer we can paint after 2 weeks, but the putty is still pretty soft and you have to be very careful not to deform it when brushing....its not dragging though.

I am under a fair bit of pressure from teh client to install the sashes ( frames already fitted and windows blocked off with OSB) but we wanted to hold off and paint the sashes on the bench before fitting as its easier to get a better job that way and we dont have to battle the weather.

If we do end up having to install the sashes with the putty ( we have painted the wood) unpainted, will this cause any issues to teh putty's drying process or give problems down the line? Thinking maybe fit the sashes and pop them out again when teh putty is drier....?

Using ( at clients insistence) Farrow and ball water based exterior paint.

Thanks
Only to add that I have used water based F&B exterior eggshell very successfully with trad putty, but yes, I did have the luxury of leaving the putty to cure. I resolved to not use trad putty on my future projects for this reason.

Cheers
 
Pull out the putty and replace with a hybrid polymer, paintable next day.

Did you dust the putty properly with whiting or plaster ? Sounds like the putty may have been too oily to begin with.
I suspect you might need a really good adhesion primer under the farrow and balls waterbased, I recommend Tikurilla Otex or maybe Zinsser.

I never use putty anymore, its only advantage is price.
 
Pull out the putty and replace with a hybrid polymer, paintable next day.

Did you dust the putty properly with whiting or plaster ? Sounds like the putty may have been too oily to begin with.
I suspect you might need a really good adhesion primer under the farrow and balls waterbased, I recommend Tikurilla Otex or maybe Zinsser.

I never use putty anymore, its only advantage is price.
Thanks , can I paint the F&B system over the Otex without issues? I did dust with whiting, yes
 
Hi, coming back to this because the putty is still as soft as when we had it done, despite 3 weeks of drying. We have started painting using the Tikurilla Otex water based primer. We tried both types, the oil based was too thick and difficult to apply on the soft putty without marking it.

Applied a first coat of the Farrow and ball topcoat and today on inspection, we see the result as in the enclosed picture. Any idea whats going on?

Need some advice as to how to proceed, the sashes MUST be installed, due to client pressure, I cant leave them without windows any longer.

If I do this, should I cover the putty with the Otec primer and leave outside to cure? Will this cause any issues to either the paint or putty later?
 

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I know several threads exist on here and have looked at most. I have a specific query regarding the sashes I am currently making and installing. They were glazed using trad putty 2 weeks ago, stored in the house & workshop for painting. I am told by the glazer we can paint after 2 weeks, but the putty is still pretty soft and you have to be very careful not to deform it when brushing....its not dragging though.

I am under a fair bit of pressure from teh client to install the sashes ( frames already fitted and windows blocked off with OSB) but we wanted to hold off and paint the sashes on the bench before fitting as its easier to get a better job that way and we dont have to battle the weather.

If we do end up having to install the sashes with the putty ( we have painted the wood) unpainted, will this cause any issues to teh putty's drying process or give problems down the line? Thinking maybe fit the sashes and pop them out again when teh putty is drier....?

Using ( at clients insistence) Farrow and ball water based exterior paint.

Thanks
Water based paint incompatible with putty. Must be oil paint.
This time of year putty outside isn't going to dry off enough to paint for some time. It only needs to be touch dry, not set hard. Best done in the workshop at least as far as primer and then finished in the spring.
 
Hi Jacob, OK...so if we have already tried some with the water based, how do we best deal with that? Hopefully not too late for the rest, but surprised no one has pointed this basic fact out before!

And will it be OK unpainted outside? I was worried primarily about water ingress between teh putty and glass.....
 
Hi Jacob, OK...so if we have already tried some with the water based, how do we best deal with that?
Dunno! Paint over it with oil paint I guess.
Hopefully not too late for the rest, but surprised no one has pointed this basic fact out before!
Perhaps more basic opinion than fact - but you can paint just touch-dry putty with linseed oil paint. I guess other oil paints ditto.
And will it be OK unpainted outside? I was worried primarily about water ingress between teh putty and glass.....
Seems to last 6 months or so pretty well. Might need a bit of making good if left too long. Hot sun dried it out a bit fast, if not already painted.
 
Well we have spent all day painstakingly washing off the fresh water based paint taking great care not to mark the putty under. Its taken all day. Not happy about leaving a base layer on the putty that might peel off taking the oil based with it, so hoping to re do using the Tikurilla oil based primer, then the F&B ***** over the top.
 
Sorry you’re having a bad time.

What brand of putty are you using? 3 weeks should be long enough to make a difference.

Oxygen hardens (cures) linseed putty. Heat (temporarily) softens it. If you are working in a highly heated space with little air flow, that might be exacerbating your problems. If you can work in a colder environment, the putty should be a little firmer.

For homeowner repairs, linseed putty often cures out in the elements on installed windows for weeks before painting without any problems.

Note that the oily nature of the putty and the fact that it softens with heat are useful properties to understand not just here, but also when applying it. If the linseed putty is too soft to apply easily, put it in the fridge before use. If the putty is a bit hard, heat it up in your hands. To keep the putty from sticking to your hands, moisten your hands with water. Just a little moisture will act as a barrier.
 
Also, although putty should be paintable after two or three weeks, it is true that it’s likely to be soft enough that it still needs some care. Jabbing the brush into it or poking it with fingers could leave a mark. Brushing with easy strokes should work fine at 2-3 weeks though.
 
I think F&B would say that you need to use their own primer/undercoat.

The product advice sheet for the F&B primer gives some guidance on painting over putty. https://www.farrow-ball.com/media/wysiwyg/Product-Advice-Sheets/Paint-primers/GBWPR.pdf
Basically - for best results use acrylic putty - for trad putty follow mfr guidelines for drying etc then paint over with the F&B system (I have done this successfully in the past.)

Depends what putty you have used and what guidance there is for that - just looking at Hodgsons for example, they say paint as soon as a skin has formed and within 7-21 days and within 28 days for topcoat (that I guess is for outside).

The main problem I have always found with trad putty is the time it takes to work it to a good consistency before applying it - the oil tends to separate and so it starts off as a gloopy mess which requires endless kneading to dissipate the oil.

Probably too many variables for anyone else to know what has gone wrong with your situation. Is it really too late to follow @Ollie78’s advice above?

Cheers
 
....

The main problem I have always found with trad putty is the time it takes to work it to a good consistency before applying it - the oil tends to separate and so it starts off as a gloopy mess which requires endless kneading to dissipate the oil.
......
Gloopy mess means old stock. Best to buy it in quantities just enough for the job, so that it's nice and fresh and not been long on the shelf. Then it's easy to handle but still benefits from a bit of kneading to take up the oiliness, makes it less sticky on the hands, and to warm it up. Knead it on a board, just working it about with a putty knife until you can handle it without getting oily hands.
I've never used anything else, not least because it's very cheap and very effective - can last 100s of years if maintained with a bit of paint.
If it's very old it's can be softened with a quick blast in the microwave.
 
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Sadly, yes, too late to start again, as per Ollys advice. Next batch I will look into using a different putty - I got the sashes glazed by a professional glazer this time, who did them much quicker and better than I could, he uses trad putty. He did use Hodgsons putty. And obviously us keeping them indoors has not helped. Going to try the oil based Otex primer now. Thanks for all the advice
 
As said air flow will help, a fan blowing over them should speed things up.

Water based paint and linseed oil putty don't always play well together.........

The traditional is linseed and oil paint.

The oil paint prevents the putty from going solid, and allows damaged panes to be easily replaced
 
Sadly, yes, too late to start again, as per Ollys advice. Next batch I will look into using a different putty - I got the sashes glazed by a professional glazer this time, who did them much quicker and better than I could, he uses trad putty. He did use Hodgsons putty. And obviously us keeping them indoors has not helped. Going to try the oil based Otex primer now. Thanks for all the advice
If you are going to use an oil based primer, I would possibly check with F&B before finishing. I used F&B exterior eggshell and primer on a steel table that I had first primed with some oil-based specialist primer - the top coat crackled and blistered. I think this would have been avoided with an intermediate water based primer - I use Zinsser 123.

Cheers
 
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