# Removing putty from old windows & glass replacement



## Coon

I am attempting to remove 90 year old putty that is very hard to remove. Any ideas? I have even thought about breaking all of the glass that I have not already broken and replacing. Could this be more energy efficient if I got a thicker glass. Any suggestions are appreciated.


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## wrangler

Unfortunately, there is not a realy easy way to remove glazing putty that has hardened after so many years. A sharp chisel and a painter's tool (often refered to as a 5 in 1) work well, but it is still tedious. Also be sure to wear gloves and eye protection as the glass will break if you get your tool inbetween the glass and the frame. Also watch for little metal triangles (called 'points') that were placed around the frame to hold the glass into place while the glazier glazed the window. These will need to come out as well. And yes, you can replace with thicker glass, though many people prefer the beauty of old glass with its flaws. 1/8" glass wont offer significantly better insulation against cold/heat but will offer better breakage protection. 
Brett


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## sirwired

Glass of any reasonable thickness is an awful insulator. You would really need to go double-pane to make any difference.

SirWired


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## chrisn

Never tried it but when I researched the same subject years ago this came up. I just used sharp chisels,heavy duty razer knife,etc


http://www.tools-plus.com/prazi-pr-9000.html


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## mark942

**** said:


> I am attempting to remove 90 year old putty that is very hard to remove. Any ideas? I have even thought about breaking all of the glass that I have not already broken and replacing. Could this be more energy efficient if I got a thicker glass. Any suggestions are appreciated.



Do not break all Your Glass!!!!!!!! 
Use a heat gun, I bought mine just for the reason your talking about. Works like a champ. Replacing older glass with new glass is a bummer IMO. They do not match. Older glass will have (for lack of a better term) a wrinkle to it. New glass will be a little bit different, flatter. You might try and find a piece of older glass in a older window, cut it to fit. That is what I did. But the heat gun will work great for you. http://www.hectorshardware.biz/shop/product.asp?dept_id=181401&sku=339921&

Good Luck :thumbsup:


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## chrisn

The only time I tried a heat gun ,I broke all the panes.Must be some trick to it that I could not figure out because I have heard that from others also.:thumbsup:


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## mark942

I can not make comment about others. All I can say is that a heat gun has worked for me for many years now. I have had no problems with removal of putty from windows. :thumbsup:


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## bjbatlanta

I bought one of the Prazi "putty chasers" some years back. It works fairly well, just be careful. It will chew up the wood if you slip with it or get off track. If I recall, it requires a fairly high rpm drill also. More than the average cordless.....


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## Nestor_Kelebay

chrisn said:


> The only time I tried a heat gun ,I broke all the panes.Must be some trick to it that I could not figure out because I have heard that from others also.:thumbsup:


Chrisn:

The problem is that if you heat only one area of the glass, then that area wants to expand, and that cracks the cool glass that doesn't want to expand. That's the reason they set sealed units on setting blocks in the middle of the opening and then use window tape around the perimeter of the window (between the glass and the wood moldings). The soft window tape and caulk above it allows for a bit of expansion and contraction of the glass from summer heat to winter frost. When you use a heat gun, you're exposing only one small area of the glass to 250+ degree temperatures, and the resulting thermal expansion cracks the cool glass, and that crack then propogates into the hot glass too.

If you're removing putty from windows with lots of small panes in them, have a piece of 1/8 inch thick steel cut that will fit over the glass. You can then move the steel a bit one way or the other to better cover the area you're working on. The metal will protect the glass from the heat of the heat gun, and will conduct heat laterally over a larger area so that heat dissipates quickly as well. Also, the metal will be at a more uniform temperature, and hence so will the entire surface of the pane of glass, and that prevents thermal cracking.

But, it seems to me kinda dumb to be REPLACING glazing putty. Putty was used many decades ago before there were quality caulks. If I were doing this work, I would remove the old putty and replace it with a quality caulk that would last many times longer than putty.

The caulk I would choose is Kop-R-Lastic, made by the U.S.E. Hickson Company in Canada. Kop-R-Lastic is a synthetic rubber caulk which has a cohesive strength even higher than it's adhesive strength. That means it sticks to itself even better than it sticks to other materials. So, when you want to remove Kop-R-Lastic, you just get one end of the caulk started and it pulls off the window like a rubber rope.

http://www.usehickson.com/Koprlastic/ThermoplasticConstructionSealant/KopRLastic_Guide.shtml

The U.S.E. Hickson company makes Kop-R-Lastic under licence from the Koppers Company of Australia, who in turn are a subsidiary of the Koppers Company who have their head office in the USA. U.S.E. Hickson of Canada was bought out by the Henry Company of Canada, but they are still making Kop-R-Lastic under the U.S.E Hickson name.

http://www.usehickson.com/

U.S.E. Hickson also has their own brand of caulk and sealants called "Stone Mason", and the only difference between Stone Mason Gutter and Siding Sealant and Kop-R-Lastic is that Kop-R-Lastic comes in 9 different colours, where Stone Mason Gutter and Siding Sealant only comes in white and clear. So, if you see "Stone Mason Gutter & Siding Sealant in the eavestrough aisle of Home Depot, it's exactly the same stuff as Kop-R-Lastic, only in a different tube.

I understand that Henry is a big name in the USA. I don't know if the Henry Company is planning to sell Kop-R-Lastic in the USA or not, or to sell the same stuff under a different name like U.S.E. Hickson was doing with their Stone Mason Gutter & Siding Sealant.

But, THAT is truly an excellent caulk to use for windows because it sticks and stands up as well as any other caulk, but it makes removal a breeze.


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## chrisn

If you're removing putty from windows with lots of small panes in them, have a piece of 1/8 inch thick steel cut that will fit over the glass.


Thanks,I will keep that in mind.


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## bofusmosby

Well, I'm going through the same process as **** is. I am restoring an old house, and completely restoring each and every window sash as I get to it. I am using glazing compound on mine. I understand that the caulk may last longer, but the original glazing compound lasted over 80 years, so I am confident that the glazing compound I am using will last longer than I will last.:laughing: Most of my sashes have major (old) termite damage, so I am disassembling each sash to do the restoration. I have found it easier to remove the nails holding each sash together, thus taking the sash apart, making it easy to remove the glass without breaking it. It takes quite a bit of time for each one, but the finished product makes it well worth it.

Bofus


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## Nestor_Kelebay

Well, if you're intent on using putty, then at least use it the best way you can:

Glazing putty is nothing more than a mixture of clay and linseed oil. Linseed oil is a "drying oil", which means it reacts with the oxygen molecules in the air to transform from a liquid into a solid.

So, before applying your putty, paint your wood sashes with raw linseed oil, allow plenty of time for it to soak in, and wipe off any excess oil from the surface of the wood that would prevent the putty from sticking well to the wood. Then, when you apply glazing putty to the wood, the linseed oil in the putty will crosslink with the linseed oil already in the wood to bond the putty firmly to the wood.

After you get your windows glazed, use an exterior oil based primer on them. The alkyd resins in the primer react with oxygen exactly the same way as linseed oil, and you will get some of that same kind of bonding between the alkyd resins in the oil based primer and the linseed oil in the glazing putty. (Ideally, it would be best to use a boiled linseed oil based primer, if you can still find it for sale anywhere.)

Anyhow, I don't have windows like you have, so I've never done this myself, but I understand why doing it this way would result in the putty sticking better to the wood, and the primer sticking better to the putty, and hopefully, that will result in a longer lasting job.


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## bofusmosby

Nester

The first couple of windows I did, I did it with the linseed oil as described. However, I have found that for me, oil-based primer used before the glazing worked better. The primer adheres to the wood great, and so far, the glazing compound sticks and holds very well to the primer. One of the problems I had by using the linseed oil was, even after 3-4 weeks after application, when painted, the primer and paint had a tendancy to "bubble up" on the glazing compound. The can of glazing compound said to waite a week or two, so I gave it more than twice that amount of drying time, and it still lifted. I had to remove the primer and paint off the glazing compound, and waite over a month before re-applying primer and paint. I am having to do about 30 of these windows (a long and slow process), so I guess that time will tell. I am sure to make notations in my journal about the methods that are used for each window, so if and when there is a failure, I'll know what not to do.


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## Skuce

Bumping an old thread to clarify some mis-information.

First off.

There is no product in existence today that can replace Traditional Glazing Putty.
The material is designed to be a flexible bond between 2 very dissimilar material for many many many years.
Now you may say that Caulking does just that....sure....maybe for 10 years if you're lucky. Then it has to be replaced after it fails horribly.

Now I know of a building in the Eastern seaboard that has the ORIGINAL putty still intact since the 1640's.
The key is that putty needs new oil added to it ever 5-7 years to keep it flexible. If that is done...there is no reason that putty won't last 1000 years.
It is a fact that the Nixon family (yes...THAT Nixon) home has records of the window glazing putty being re-oiled every 5 years for the last 300 years. It is still in near-new condition. And that's afters centuries of rain and winters being thrown at it.

I don't know of a SINGLE Caulk-type product that can boast a track record even close to that.

Now Real glazing putty is a mixture of high calcite Lime and Boiled Linseed oil (higher grade the better). It is NOT Clay.
The higher the Calcite content...the better. ie: less than 5% Magnesium content.
How it Dries and Cures are 2 very different things.
First off...the Oil is a drying oil. It Oxidizes and dries in the mix after about a week of environmental exposure.
Next is the Cure process. This happens when the Lime is exposed to the Carbon Dioxide in the air. The Lime reverts back into it's original Calcium Carbonate (Limestone) form in about a Year time, if it's painted with a Latex. If it is sealed with an Oil based paint. Full cure time is stretched to about 30 years.

Now you want the Putty to remain flexible to continually compensate for the 2 dissimilar materials expanding at different rates. So the longer it takes to fully cure...the better.
Hence why the 5-7 year schedule of re-applying linseed oil is such a good idea. It keeps the putty flexible for centuries.
Just paint on a layer of linseed oil right over the painted glazing surface. It will soak right in and do it's job.

Note: a little bit of a note about the wonder-material of Lime is that it's Self-Healing. If any Micro-cracks form in the lime, they heal themselves closed again. Because that micro-crack is then exposed to the air. The lime absorbs carbon-dioxide and carbonates faster and grows tiny calcium carbonate crystals to fill the crack. 
There aren't any Caulk products on the market that Self-Heal.

Now. You ask how to REMOVE old putty that has finally failed after a 100 years of no-maintenance (which is why most people get rid of their heritage windows).

Simple: A little mixture of House-hold Chlorine Bleach and Raw Linseed oil.
Put it on the window glazing putty (with the window flat on a table) and let it soak in for about a day.
The Raw Linseed oil will start to work away at the oil-dried out Boiled Linseed oil and start to re-emulsify it.
The Chlorine bleach will start to attack the lime and break it down.
Then take your Roller-Chisel ....

http://www.swedepaint.ca/i/tools/rollerchisel3lg.jpg
http://www.swedepaint.ca/i/tools/rollerchisel3Blg.jpg
http://www.swedepaint.ca/i/tools/rollerchisel3Clg.jpg

... to ride on the flags of the muntin bars to cut out the old putty.
(I am not affiliated with Swede Paint...it's just the only place I know that sells the chisel)
Heating the old putty is a dangerous way of just reactivating the old linseed oil. Most people will have greater than a 30% loss rate of the glass.
Heat-Guns in general should be banned. They output far too much heat for any practical use. They destroy glass and cause the off-gassing of white lead ALL THE TIME. They are also a great way to burn your house down.
Think of this for a moment. 1000*F hot air being blown into a crack around a window architrave and igniting a pile of ant chewed saw-dust. Wood spontaneously combusts at around _575_*F.
It's something stupid like 20% of all house fires in the USA are caused by heat-guns.
If I remember right. White Lead based paint turns into lead vapour around 375*F and will kill you.

Heat-Guns are BAD.

Ok. Back onto something happier. lol

Now when you put in new Glazing points (those triangle metal things holding in the glass)
Make sure you get some that are Zinc plated. The Zinc reacts with the lime and self etches the glaze points into the putty for a great bond.
Easiest way to tell if they are not marked on the package....is to look at the colour. Zinc has a slight Blue tint to it. Once you start seeing that Blue tint...you'll never miss it again.
Just like how Stainless Steel has a slight Yellow/Honey tint to it. Once you start seeing it...you Can't-Not-See-It. haha.

Regarding DAP-33. It is not an appropriate product to be using. It takes Forever to dry to a point that is good to paint. It does not have super-longterm flexibility. There are no known chemicals/solutions that will remove it. It is also about the same hardness as Portland Cement once it does cure. It is a Nightmare to try and remove it once it has dried. Plus Good Luck getting it all out without breaking the glass. It's just too hard. It is also not self healing.
The only thing that it is a good for is application ease. It goes on almost the same as Traditional Putty. BUT beyond that it fails in almost all other respects.

Regarding Caulks. They are long term flexible (5-10 years..20 if you are Super Lucky). Application is not easy and clean-up is annoying at best. They also look like crap in a any pre-1700 to 1920 era window. That sharp-cut chamfered edge is what makes the exterior character of a heritage window just pop with class IMO.

IMO nothing can replace Lime/Linseed Putty. To me it's an absolute wonder-material that has been around for the better part of 1000 years. That's the kind of track record that I'm going to trust. Not some New Fangled Product in a tube that has had "5 years of simulated use" put to it. I'll pass on that.


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## chrisn

Wow,good info!:thumbsup:

Where would one get the traditional putty?


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## Skuce

Up here in Canada there is actually only one company that makes it. It's usually under the name "LPL Mastic Putty" and comes in a 1lb plastic baggy.
I don't know what companies in the USA make it/carry it.

I do know that Viking Sales in the USA carries the Swedish made stuff...










http://www.solventfreepaint.com/window_glazing.htm

...it's really high end stuff. Closer to Restoration/Heritage quality. But it is really excellent to use.

The every-day Putty comes in a little plastic pouch. You can usually see the yellow linseed oil separating in the pouch. Just like the way peanut butter separates. It's not as awesome as the Swedish stuff, but it is easier to get a hold of.










I also recommend the Silent Paint Remover from Viking sales. I bought mine from the Canadian distributor....but it's the same thing.
These paint strippers make Heat Guns look like a base model Honda Civic compared to a Lamborghini. I've never used one that makes stripping paint so easy.

http://www.silentpaintremover.com/










(again...I'm not affiliated with any company...I'm just showing what I have used over the years and what works consistently)


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## chrisn

Thanks for the info


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## Skuce

No problem!


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## youngblood50

Firmly agree with man oof many hats. All my 100 yr. old double-hung windows have been reglazed after removing the glass, I have the old bubbled glass which distorts everything if looked if you lookthrough it at an angle. I used a small propane torch to soften the glazing compound, worked really well for me. My Dad swore by Boiled Linseed. After removing the glass I thoroughly cleaned and sanded the rail that the glass sat on then liberally coated the rail with oil. I did this until the wood wouldn't absorb any more. I could be wrong but I figured the oil will help the frame repell moisture and as the compound begins to dry it can wick out the oil that's in the wood, just let it dry thoroughly, I usually read directions with one eye closed unless it's something that could possibly injure or kill me or totally infuritate my wife. Good Luck


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## a_petal

I am in the process of restoring a 100 year old storm window..thank you for the tip of softning the putty with linseed oil. This stuff has endless uses, and is enviro friendly to boot. I got my linseed putty from http://www.swedepaint.ca. once I get the glass out I'm using the silent paint remover to get the paint off. I used the silent paint remover on my front porch. Ive tried all paint removers legal and otherwise, and NOTHING removes old paint the way this box does. I do not work for swede paint either, I just love thier products so much, I can't help but tell everyone I can. It costs way more than the big box store..but at least I'm not poisoning myself with alkyd, and painting every 5 years. Get a can of their paint or any other product and see for yourself!


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## norkota

*To Skuce*

Skuce, Deeply appreciated your sharing of obvious wisdom and knowledge on glazing windows.


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## Matthewt1970

Replacing glass, putty, blood, sweat, tears, trip to ER for 10+ stitches, time, primers, paint, new tools, sandpaper

VS.

Replacement windows which typicly take an hour to install and in most states will get you a tax rebate.


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## bofusmosby

Matthewt1970 said:


> Replacing glass, putty, blood, sweat, tears, trip to ER for 10+ stitches, time, primers, paint, new tools, sandpaper
> 
> VS.
> 
> Replacement windows which typicly take an hour to install and in most states will get you a tax rebate.


The truth to be told, those old windows will last another 100 years if taken care of, while the new ones will need replacing in 20 years!


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## 95025

Matthewt1970 said:


> Replacing glass, putty, blood, sweat, tears, trip to ER for 10+ stitches, time, primers, paint, new tools, sandpaper
> 
> VS.
> 
> Replacement windows which typicly take an hour to install and in most states will get you a tax rebate.


Or more likely...

$100

VS.

$5000


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## epson

I’ve used heat gun, Goo Gone and Easy Off oven cleaner to remove old hard window putty.


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## Skuce

I figure I should add to this page a bit since I have changed a few things in my company since that first post.

I exclusively use Allback Linseed Oil Paints now. None of the other paints I have used in the last 3 years have held up. The fail-highlight was Ben Moore Aura that I tested in 2009 failed in 6 months! I don't want any of the work coming out of my shop to fail. I put too much work into it.
I am also NOT affiliated with Allback at all. I just really have had great results with their products over almost everything else that I have tried over the years.

Now regarding some of the Allback paints getting mildew. It's a 2 part situation. There is nothing in the paint itself for mildew to feed off of....but the food in the substrate surface gets mixed into the paint as you brush it on contaminating the paint. Then it will mildew.

Solution 1: Add up-to but no more than 10% Zinc Oxide (also from Allback) to the paint in the can. The zinc oxide makes the paint toxic to moulds and microbes so the mildew doesn't grow. They ship it separately from Allback because of the strict zinc regulations in Europe.

Solution 2: "Linseed Soap Extra". It's a Linseed soap that has Boron Salts and Ethanol in them. Wash down your existing mildewy paint with this stuff. The alcohol and the boron kills the mildew off. Plus the boron stays in the paint afterwards to kill off further growth. Usually 2 applications 6-12 months apart does the trick.


Now regarding Putty.

I only use Allback putty for doing requested Museum work currently. The rest of the time I use Sarco Multi Glaze (Type M). It skins over for painting in 3-5 days in the shop. The Allback takes about 24 days to skin over for painting with a Latex/acrylic. Oil can be painted on in 1 day "if" you order the USA formula of Allback Putty and not the European formula. The Euro formula is too "loose" in my opinion.


I also just got a job with a customer because my window restorations came in 400$ PER WINDOW cheaper than the Window Replacement guys. And my work will last 40-100 years easily, where the replacements usually start falling apart in 4-12 years.
Which is better for your money?


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## Skuce

Oh. For removing Impossibly hard putty. The kind that steam, heat or chemicals won't soften. Then you'll need a "hacking knife". C.R. Laurence carries them. Using a hammer against the knife to peel the putty away from the WOOD...not glass. It works! Just the first use of it is scary until you get the hang of it.


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## 1tomacz

*putty*

there is an outfit called NUPUTTY,formerly of desplaines illinois,this stuff
holds up 30-50 years,tru valu hardware stores often have it
when applying it,see that the rabbet is smooth,a bit of a rounded edge,if the glass is freshly cut,use fine grit sand paper to round off the sharp edges,use
the glass cutter to chip,then round & fine sand each glass corner,glass that gets this done will take some pretty hard slams by kids (or party animal adults) without breaking.rabbet is bedded with as small bead(!/16 in thick when pressed into sash seat),use cold chisel to tap in glazing points,use chisel only for this purpose ,angling the beveled edge flat along glass surface, sinking the point into
the primed wood,making a snug,secure seat for the glass.
roll & kneed a putty roll , thumb press onto the joint, use a 3/4 bent knife
(embee brand,one inch for double strength glass) to slowly smooth,press the putty into the joint,make an inset angle at corners,making a track for water run off..
points should be invisible,the knife should leave a very smooth putty surface,it
should dry for a year before painting


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## bella_b

To Skuce - Thank you for you post, both intelligent and informative. At last I've an answer to a nagging question. Thank you


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## MEE123

Good post. I've got to decide whether to try this myself or pay a local window restoration company to do it.


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## mattiej777

There is a new attachment for oscillating tools called the Putty Chomper. It is Fantastic!! Try puttychomper.com


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## mattiej777

There is a new attachment for oscillating tools, it's fantastic! try http://www.puttychomper.com


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## Davejss

There is a tool specifically made to heat up old window putty. It looks like a soldering iron, with a 90 degree point on the end. It works great.
I have restored countless old colonial windows in the Concord, Mass. area using our window iron. Some of that putty was approaching one hundred years old, or older, and was hard as a rock. Take your time, let the heat do the work, and remove the softened putty with a stiff putty knife.


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## traghel

Bumping this old thread because I am working on a very similar project.

I took one sash out of a 1920s (?) frame and tried to remove the putty mechanically, mostly using a chisel. I did get all of the glass out, though I broke a few in the process.

But an encrustation of old putty 1/16"-1/8" thick remains, so after reading this posting I thought I would try the raw-linseed-oil-and-bleach method. I mixed up a 50:50 blend and brushed it on the putty. I would say it has softened a tiny bit in the past 48 hours, but not enough to make it any easier to get off.

Can anyone with experience with this method make any suggestions? Reapply? Different blend? Give up and try something else?

Should say I assume that this is linseed oil putty, but I don't know for sure. The building was built in the 1980s, but the windows were salvaged from earlier construction. Whatever it is, the putty is rock hard.

Many thanks,
traghel


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## ToolSeeker

Have you tried heating it to soften it?


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## traghel

On a second experiment with a heavier coating of the linseed oil and bleach mixture, it did more-or-less liquify the putty. But it took a lot of oil-and-bleach to liquify a small amount of putty, so I'm not sure whether that will be practical in the long run.

I have not tried heat yet, no. The consensus seems to be that the infrared devices work better than heat guns for removing paint, but what about putty?

Also, how much of the putty do I really need to remove? Clearly I need to get the mating surface between the glass and the mullion clean (i.e., where the inside face of the pane actually touches the wood). But do I need to get it all off the outside edge of the mullion, which will actually take the new putty (i.e., the surface perpendicular to the pane)?

Thanks again,
traghel


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## cobus naude

*removing putty and still remove the pane*

I had the task to remove old putty and the replace it with silicon

The problem was that old butty is very hard, so te problem was to remove the putty and the window pane without breaking the pane

I used Q20 a product used to losen ruster bolts

by spraying the putty with this, inside and outside the putty lets go from the woord, there is stil a bit of elbow grease required, the method did make things a lot easier


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## Nestor_Kelebay

*Please don't wreck your putty.*

Window glazing putty is nothing more than linseed oil mixed with clay. It was used at a time before there were high performance caulks.

If you have to repaint some old colonial windows, then:

1. Remove the old putty from around each window

2. Put glazing points in to hold each glass pane in place.

3. Now, CAULK around each pane with KOP-R-LASTIC caulk.

Kop-R-Lastic is marketed in the USA by the Henry Company, so whomever sells Henry construction products in your area should carry Kop-R-Lastic in at least clear and white.










Kop-R-Lastic has the major advantage is that over the course of 3 or 4 years it cures to a cohesive strength that's even greater than it's adhesive strength. That is, after several years, it'll stick to itself better than it sticks to other common construction materials. So, if you ever want to remove the Kop-R-Lastic, you just get one end started, and it pulls off cleanly like a rubber rope. And that saves a great deal of time when it comes to refinishing multi-panel windows.

Here is a picture of me pulling clear Kop-R-Lastic caulk off Suite 3's dining room window:










I'm pulling hard and the caulk is coming cleanly off the white vinyl it's stuck to. If you could enlarge this picture, you could see it better.

But, using Kop-R-Lastic caulk will make refinishing colonial windows a breeze, and you no longer have to deal with putty at all.

Kop-R-Lastic tools easily with a soapy finger and it's paintable.


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## shaftmaster

I've done a lot of research and the information on the Historic HomeWorks web-site about restoring old windows is very thorough and helpful. Here's the link to using steam to remove paint and putty from window sashes:

http://historichomeworks.com/forum/viewtopic.php?t=1587

Anyway, I'd be hesitant about using chemicals (chlorine bleach, etc.) to remove old putty since it's hard to say whether these chemicals could remain in the wood and cause the new paint or putty to have problems later.


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## Andiy

Must be nice to have those job-specific tools - we didn't have them back in my old glazier days; we had to get the tip of the flame on a standard propane torch nice and fine, and have a steady hand. I couldn't guess at how many windows I re-glazed that way, torch in one hand and chisel in the other, but the precision of that torch (and the user) applied the heat specifically enough to remove the putty without damaging the frame... or the glass, if we were just replacing the putty.

I'm not sure I'd advise anyone to do it that way though. We were paid experts.


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## Nestor_Kelebay

People should realize that putty is nothing more than clay mixed with linseed oil.

I expect that paint stripper would soften up putty just as it softens up dried linseed oil based paints. The active ingredient in paint strippers is methylene chloride, and methylene chloride evaporates completely without leaving a residue. If there's anything remaining behind after paint stripper evaporates, it's the gelling agent that they gelled the methylene chloride with. That should wipe up easily with a paper towel dampened with mineral spirits.

And ditto for heat. Heat should soften old putty so that it can be scraped off more easily just as it softens old linseed oil based paints.


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## JourneymanBrian

Ammonia also fully evaporates and you can mix it with wallpaper paste for consistency.

Anything with basic pH should do it, but as Nestor mentioned, if you use something leaving a residue you'll have to clean the surface thoroughly after.


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## shaftmaster

Nestor_Kelebay said:


> People should realize that putty is nothing more than clay mixed with linseed oil.


Glazing putty is lime mixed with linseed oil, not clay.


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## halliwellc

chrisn said:


> The only time I tried a heat gun ,I broke all the panes.Must be some trick to it that I could not figure out because I have heard that from others also.:thumbsup:


Must shield glass with sheet metal if using heat gun. Heat gun not recommended; infrared heat is preferred because wavelength passes through glass harmlessly.


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## halliwellc

mattiej777 said:


> There is a new attachment for oscillating tools, it's fantastic! try http://www.puttychomper.com


Wood sash windows don't react well to being chomped. It looks like the company got chomped now too.


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## Nestor_Kelebay

shaftmaster said:


> Glazing putty is lime mixed with linseed oil, not clay.


Yes, you are correct. Glazing putty is polyunsaturated soy bean oil mixed with chaulk (calcium carbonate), which is close enough to lime in my books to be called lime. It's actually limestone.

http://www.dap.com/docs/msds/00010401001_english.pdf

The soy bean oil behaves just like linseed oil in that it dries when exposed to oxygen in the air. The chaulk really doesn't do anything, so I expect you could mix almost anything with linseed oil or unsaturated soy bean oil to make a window glazing putty of some sort.

But, the point is that anything that will soften linseed oil based paint will soften dried up window putty too.


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