Glazing Putty: Maintenance and Repairs
Post new topic   Reply to topic
Historic HomeWorks Forum Forum Index -> Windows & Doors  
View previous topic :: View next topic  
Author Message
johnleeke
Site Admin


Joined: 20 Aug 2004
Posts: 2914
Location: Portland, Maine, USA

PostPosted: Tue Oct 13, 2009 5:52 pm    Post subject: Glazing Putty: Maintenance and Repairs Reply with quote

Glazing Putty: Maintenance and Repairs

(Update: 7/2/16 revised tool list, added step 2.; 9/27/15 added tool list)

Traditional glazing putty has been carefully developed over the past four centuries to be easy to apply, keep a good seal between wood and glass for many years, and then fail gracefully. The way it fails is an important part of the glazing system. It fails so that it is easy to remove and replace with more putty.

People who are struggling (or spending a lot of work, time and money) to get the old putty out don't realize that it is often possible to leave it in place and do simple putty maintenance and spot repairs.

Condition to be Treated: Putty failure in tightly localized spots.

Description: Remove sections of loose putty, seal cracks in putty and paint. This treatment is suitable for sections of missing and cracked putty when the remaining putty is tightly adhered or is in good condition. If more than 25% of the putty on a sash is damaged, consider completely reglazing the entire sash. Save all putty in good condition if doing a conservation type of treatment. Movement of the sash and shrinkage of the putty over the long-term causes the putty to crack and fall out. Spot putty maintenance helps seal the glass to the wood helping to prevent movement of the wood due to moisture; it can extend the life of the putty for several or many years. Many spots on more that one window can be treated at the same time, achieving an efficiency of scale. Linseed oil materials may dry and cure slowly. For a faster production rate a penetrating drying oil can be used instead of boiled linseed oil. This may shorten the life of the repair somewhat, so use boiled linseed oil for best durability and longer life of the repair.

Typical Procedure:

1. Remove loose putty with a utility knife and pull-type scraper. Don't go crazy trying to get all the putty out, just take out what is loose. If it is well attached just leave it. Use a 1/2" wide brass brush and pull-type scraper to to clean up glass and wood surfaces in the glazing rabbet. The surfaces must be perfectly clean: bare bright wood, and sparkling glass. A razor blade may be needed on the glass.

2. Clean paint off of glass, and even up the edge of the putty where it meets the glass to form a more-or-less straight line. Use a razor blade in a holder for scraping and a drywall knife as a stop to protect the putty.

3. Mask off the neighboring glass and wood surfaces with 2" wide blue masking tape to the glass along the edge of the putty before starting. Also apply tape to the face of the stiles and rails if you will not be repainting them.

4. Brush a pre-treatment on any exposed bare wood in the glazing rabbet and let it dry. Pre-treatment can be the traditional boiled linseed oil mixed with turpentine or alcohol, or a contemporary penetrating oil-base primer product, such as Penetrol.

5. If the putty has cracks but is still well attached, brush some boiled linseed oil onto the line of putty and brush it back and forth so it soaks into the cracks. The oil will seep into the cracks, then brush again, more will seep in, come back in 10 minutes to apply a little more oil and brush, repeat three times.

6. If the putty bevel surface is rough and needs to be smoothed, sand it right in the wet oil. The oil will help control any lead-containing dust. But, DON'T SCRATCH THE GLASS WITH THE SANDPAPER. Use a thin metal slat from an old Venetian blind or strip of sheet metal to protect the glass. Do not do this step if you do not have strip of metal to protect the glass from scratches.

7. Mix a little boiled linseed oil into a bit of glazing putty so it forms a loose runny paste. Work the paste into the cracks with a tooth brush. Fill any cracks that remain open with straight putty, working it in with a putty knife. Finally, wipe off all remaining oil and putty with a rag, refill any cracks that are still open.

8. Clean up the repair area by removing the tape and cleaning off the surrounding wood and glass surfaces with a rag and a little turpentine. Safety: Do not leave oily rags laying around, they can spontaneously combust causing a building fire. Store oily rags under water in a metal container.

9. Pack and tool putty or glazing compound into the sections of missing putty, making the new putty flush and even with the neighboring old putty. Let the putty cure and skin over.

10. Prime and paint the putty with two top coats, lapping 1/16" onto glass and wood. Allow to dry between coats. Sand lightly between coats if surface feels rough. DO NOT SCRATCH THE GLASS WITH THE SANDPAPER, use a thin metal slat from an old Venetian blind or strip of sheet metal to protect the glass.

Materials:
- Blue masking tape, 2" wide
- Sandpaper, 100 grit
- Putty or glazing compound, oil-based
- Boiled linseed oil or oil-based pre-treatment, such as Penetrol
- Rags
- Primer, oil-based
- Turpentine
- Paint, top coat, oil-based or waterborne acrylic

Tools:
- Utility knife
- Pull-type scraper
- Brass bristle brush
- Razor blade in holder
- Joint Compound Knife, 6" to 10" wide (narrower than the shortest line of putty)
- Brush for oil pre-treatment, narrow
- Can with water for oily rags
- Tooth brush
- Putty knife
- Paint Kit


Quality of Results:

Best Work: Cracks are filled with linseed oil and putty. New putty is tooled smooth and neat. Paint coating presents a smooth surface and even luster. Paint and primer lap onto glass and wood. A slightly noticeable unevenness in the surface bevel of the putty is acceptable.

Inadequate Work: Remaining loose old putty or unfilled cracks. Paint does not lap onto to glass and wood. Repaired putty surfaces feel jagged or abrasive.



Tips from the Pros:
Remove any chunks of loose putty, but don't go crazy trying to get all the putty out. (If more than 15% to 20% is coming out I consider if it will be worth removing all the putty. It's usually a trade off between a limited budget now with a shorter life span of say 5 or 8 years, or spending quite a bit more now for complete deglazing and a much longer life span of 3 or 4 decades)

When using this method it can be difficult to clean putty and oil off the neighboring glass and wood surfaces, so apply 2" wide blue masking tape to the glass along the edge of the putty before starting. Also apply tape to the face of the stiles and rails if you will not be repainting it.

DON'T SCRATCH THE GLASS WITH THE SANDPAPER! If you do you'll be sorry, so DON'T. I use a thin metal slat from an old Venetian blind to protect the glass. If you can't get a Venetian slat then don't sand. (DON'T, if you do I'll just have to send you straight to your room with no dinner, then tomorrow and for the rest of your natural born days you will be looking through scratched glass and regretting it. (If you don't believe me, just ask your mommy.))

If you have to get this method done more quickly, use a penetrating drying oil such as Penetrol instead of boiled linseed oil. You can use the Penetrol on the bare wood instead of oil-based primer. This may shorten the life of the repair somewhat, so use boiled linseed oil for best work and more durable work.

_________________
John

by hammer and hand great works do stand
by pen and thought best words are wrought


Last edited by johnleeke on Sun Jul 03, 2016 3:05 pm; edited 5 times in total
Back to top
View user's profile Send private message Send e-mail Visit poster's website
muntinman



Joined: 09 Mar 2010
Posts: 16
Location: Floyd, Virgina

PostPosted: Mon May 03, 2010 5:06 am    Post subject: Reply with quote

What a fine and concise description. I tried to e-mail an architect friend instructions on this process and it was about three pages. The first time through was when I learned what can happen when your server connection expires;(

The one thing I would alter , for production purposes is the "place and pack" method. A homeowner doing a repair may not want to commit the time to learning how to "extrude and sweep" putty into the rabbet but a pro should be aware of it. One motion applies, packs and smoothes the putty. If we want to be affordable, we have to be productive, as long as the end product is adequately thought out and executed to meet the technical standards.

_________________
Phill

It's not good because it's old. It's old because it's good.
Back to top
View user's profile Send private message Send e-mail
johnleeke
Site Admin


Joined: 20 Aug 2004
Posts: 2914
Location: Portland, Maine, USA

PostPosted: Mon May 03, 2010 6:17 am    Post subject: Reply with quote

Point taken about the Place, Pack & Tool method. It is useful for training beginners to help them understand exactly how putty works. It was developed to serve the purpose of solving a few difficult putty problems for professional window specialists. Many pros condense putty placement into a technique with just one or two steps, which is fine. Technique is always up to the individual worker, as long as the result meets the standard. (Although I would insist that anyone still making putty snakes in a professional setting try another technique on at least ten windows. Well, even snakes can be OK; who would say having some fun making snakes is strictly forbidden? Not me. But, it can also be fun, after glazing a stack of sash, to lean over, stretch my back, glance at the clock and realize that I've shaved a full minute off my best sash glazing time record. Well...ALMOST fun.

It would be nice to see your full description of putty maintenance. Also, if you get the chance, could you show us the 'extrude and sweep' method of putty placement with photos or video?

_________________
John

by hammer and hand great works do stand
by pen and thought best words are wrought
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Luma



Joined: 03 Aug 2010
Posts: 4

PostPosted: Fri Aug 20, 2010 1:24 pm    Post subject: Re: Glazing Putty: Maintenance and Repairs Reply with quote

I am a first timer trying to restore my windows and am struggling with removing old putty. My windows are original to the house and have been neglected for the last 20+ yrs. Considering this, they are in decent shape. I considered replacements (pressured into it) but couldnt see throwing out perfectly good wood windows to fill my home with vinyl. Thank goodness I found your forum. It has inspired me and helped me get started on my restoration.

The windows have a great deal of loose putty which came off on its own. I have been able to remove more of it using a steam box (thanks to your forum). However there still remain whole strips of stubborn putty on a couple of sides of the individual muntins.
You stated;

Remove any chunks of loose putty, but don't go crazy trying to get all the putty out. (If more than 15% to 20% is coming out I consider if it will be worth removing all the putty.

Do you mean 15% - 20 % of putty on the whole window, or on the individual rabbet? I am working on 12/12 sashes in my home so there are many strips of putty to deal with. If I can avoid removing all the putty I will gladly take that route.
I will need some advice on how to remove the rest of the stubborn putty if it is necessary to remove it all.

Once I am able to move past the putty and all the paint is stripped and wood is nice and clean I am not sure of the next step. I appreciate your guidance with this.

btw Catherine Brooks (Speedheater) recommended your forum and I have learned a great deal from reading about how to restore old windows. I am grateful for the valuable information I have gained from your forum.
.[/quote]
Back to top
View user's profile Send private message
johnleeke
Site Admin


Joined: 20 Aug 2004
Posts: 2914
Location: Portland, Maine, USA

PostPosted: Fri Aug 20, 2010 8:50 pm    Post subject: Reply with quote

Quote:
Do you mean 15% - 20 % of putty on the whole window,


15-20% of the whole sash.

If the sash has been in the steam box you should probably try to remove all the putty (one way or another) and the glass, so you can start over, fresh.

Try using the infra-red heat lamp on those stubborn lines of putty, just be sure to protect the surrounding glass and wood (with strips of sheet metal) so you don't scorch and damage the bare wood next to the putty.

Try the method of coating the stubborn putty with raw linseed oil and letting it soak in for a day before applying the heat.

_________________
John

by hammer and hand great works do stand
by pen and thought best words are wrought
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Mark Nelson



Joined: 03 Sep 2010
Posts: 1
Location: Mount Horeb, WI

PostPosted: Fri Sep 03, 2010 9:14 am    Post subject: Putty removal Reply with quote

This information is great. Regarding the removal of old putty, I have worked with many different methods. Specifically regarding the use of chemicals, I have tried several. However, none seem to work quickly or work well enough for me to consider it a leading method. Might you have a recommendation?

Mark
Back to top
View user's profile Send private message
johnleeke
Site Admin


Joined: 20 Aug 2004
Posts: 2914
Location: Portland, Maine, USA

PostPosted: Fri Sep 03, 2010 1:39 pm    Post subject: Reply with quote

Mark, welcome to the Forum!

Here is the main discussion deglazing and removing putty:
http://historichomeworks.com/forum/viewtopic.php?t=1587

By the way, you might consider posting more details of your chemical putty removal experience, methods, materials, techniques, etc.

I do occasionally use chemical, but other methods usually work better.

_________________
John

by hammer and hand great works do stand
by pen and thought best words are wrought
Back to top
View user's profile Send private message Send e-mail Visit poster's website
johnleeke
Site Admin


Joined: 20 Aug 2004
Posts: 2914
Location: Portland, Maine, USA

PostPosted: Wed Oct 07, 2015 1:28 pm    Post subject: Reply with quote

Tool list for this method.

Tools:
- Utility knife
- Pull-type scraper
- Brass bristle brush
- Razor blade in holder
- Brush for oil pre-treatment, narrow
- Can with water for oily rags
- Tooth brush
- Putty knife
- Paint Kit

_________________
John

by hammer and hand great works do stand
by pen and thought best words are wrought
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Vander



Joined: 19 Feb 2016
Posts: 1

PostPosted: Wed Jul 20, 2016 3:37 am    Post subject: Reply with quote

johnleeke wrote:
Tool list for this method.

Tools:
- Utility knife
- Then click here to read a Wealthy Affiliate review.
- Pull-type scraper
- Brass bristle brush
- Razor blade in holder
- Brush for oil pre-treatment, narrow
- Can with water for oily rags
- Tooth brush
- Putty knife
- Paint Kit


Nice John, I think I've got all of those.

Thanks very much for posting this step by step tutorial. Must have taken a while.
Back to top
View user's profile Send private message
mw40784



Joined: 26 Sep 2016
Posts: 3
Location: Rugby

PostPosted: Wed Dec 28, 2016 1:27 am    Post subject: Reply with quote

Thanks John for share methods & procedure.
We can repair Minor defects such as dents, scratches and depressions with glazing putty. Also make effective insulation to prevent draughts from entering the property through gaps and from energy being wasted by heat escaping through the windows.
Back to top
View user's profile Send private message Visit poster's website
johnleeke
Site Admin


Joined: 20 Aug 2004
Posts: 2914
Location: Portland, Maine, USA

PostPosted: Wed Feb 15, 2017 10:44 am    Post subject: Reply with quote

Welcome to the Forum.
I'm planning a trip to the UK: London, Birmingham & Shropshire. Where are you located, maybe I can invite myself to stop by your shop for a visit.

_________________
John

by hammer and hand great works do stand
by pen and thought best words are wrought
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Display posts from previous:   
Historic HomeWorks Forum Forum Index -> Windows & Doors  
Post new topic   Reply to topic All times are GMT - 5 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum