Black Putty in old windows

[milkman]

Hi all
Not strictly a building conservation forum here but perhaps someone can help.

Working on a load of window sashes at the moment, repairing them.

Were taking the glass out and quite a few, the older panes I think, are held in with very hard black coloured putty.

It's very resistant to softening with a heat gun and is a sod to get out.

Can anyone shed light on what this stuff is?
Be interested to find out.

Cheers
Marko

 

[AndyT]

Did the house also have stained glass windows?
To fit cut pieces into the lead strips ("cames") you use a black putty which is similar to ordinary putty (linseed oil and whiting) but with added carbon ("lamp black" ie soot).

So maybe some black putty was handy and was used just because it was available.

That said, the ordinary stuff can go very dark brown, and I've heard that London is a terrible sooty place! :wink:

 

[adidat]

i recently learnt the art of window puttying from the french master himself Jean Le Puttiaye, Its a pretty tedious job, the best method i found, is to use a steel rule and bend it on to the putty and drag towards you.

I had to clean out a door in situ with very thin glazing bars and lots of expensive glass to replace a broken pane, I found an old sharp chisel worked well (still a hard job)

adidat

 

[RogerS]

If you are feeling flush then one of these is a good investment.

There was a company hiring them out based in London

 

[milkman]

Lamp black? Sounds convincing its quite a mineral texture when it crumbles.

Yes we are using putty lamps and they do work., just not as well as on newer stuff.

Will try the steel ruler, not thought of that.

Thanks!
Mark

 

[adidat]

where abouts are you? im near bethnal green!

its a shXt job, really hard to get perfect, and even then everyone needs to be really careful around it as it still soft for 30 days!

try to warm it up with your hands seems to make a difference. Tradesmens wipes are really good for getting it off stuff and hands.

adidat

 

[hanser]

Haha that reminds me.....

I once did a deal with a subbie on a new build house that I bought - colonial style windows/small panes. For not a lot he measured/made up double glazed units for me to replace the single panes and then install/putty in the new units at my leisure. Now you can imagine biggish 4 bed with bandstand bay at the rear - there were glazing units all over the place. Never one to sit around I started on one casement with 8 panes at 1900 one evening and still hadn't got it right by 0200 in the morning! By the time I finished the house two months later I was proficient. Well just about. One of those never again jobs!

 

[rafezetter]

where abouts are you? im near bethnal green!

its a shXt job, really hard to get perfect, and even then everyone needs to be really careful around it as it still soft for 30 days!

try to warm it up with your hands seems to make a difference. Tradesmens wipes are really good for getting it off stuff and hands.

adidat

Here's my "gets it done without it being a nightmare" how to (just in case) :

err - yes it's compulsary to knead it in your hands for 10 mins or so first, until it goes bluetack soft, then feed and pinch off with your thumb. Be generous with it, get a good amount on the frame and do all sides 1 pane at a time.

Grab a putty knife, (been used to a long time and shaped that way for a reason) and wet it in warm soapy water.

Push the flat tip (as opposed to the curved bit) firmly into the corner at 45deg both down and to the side to create the corner mitre and the runoff angle and slide the blade DOWN away from the glass. Peel off the excess and keep it in your hand.

Wet the blade again and place the blade gently onto the now created corner mitre with the curved part of the knife facing down, and have the knife held at a 45deg angle away from you with your arm parallel to the front of the window (and again 45 deg down too) and slowly bring it towards you using the flat tip to cut the excess off the top part of the putty while pressing down to push and set the lower bit against the frame. DO this in ONE motion, DO NOT STOP. Peel off the excess putty and knead it into the rest you had before (doing this ensures the next lot will be nicely soft for the next pane)

When you reach the other edge of the frame the reason for the flat bevelled tip of the knife will become clear as you bring it to the corner then slice down at a 45 deg angle creating the other mitre.

wet the blade and repeat for the other sections.

I'm not a pro - in point of fact I've only done it once after this window frame renovation (also my first time) but here's the result I got with zero previous training or practice :

It ain't absolutley perfect (because he wouldn't let me!) but compared to most of the others around the area I looked at it was a significant improvement (looked like blind drunk chimps had done it.).

Once the shape is set you can with care smooth out any bumps and irregularities, but you have to do it in one clean stroke, it you touch just a small portion it will create ridges either side.

http://s982.photobucket.com/user/Ra.../Woodwindows5_zps9eef5b79.jpg.html?sort=3&o=3

I actually found it quite theraputic tbh. I'd do more if ppl wanted me to.

I should add that all that work was done in 1 day - until about 7 - 8pm - as that's all I had, more time would have given a better result.