DIY Network

Old-Windows Restoration: Window Sash Repair From "Restoration Realities" episode DRTR-112

Restoration Realities "does windows" with some restoration work on double-hung windows that are original to this 1913 Detroit home.

In this episode, DIY's Restoration Realities travels to the historic Indian Village district of Detroit, Michigan, and the home Scooter and Kolleen Jones. The mission is some window repair in their 1913 craftsman-style cottage.

In this second segment, after some of the window sashes have already been removed, the techniques for repairing and repainting old window sashes are demonstrated.

For a summary of the steps and techniques used in the window-sash restoration, read on.

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Figure A

Window Sash Restoration

• The first step is to remove the damaged window sashes so they can be repaired. Our restoration specialist scores the paint joint between the wooden interior stop and the window jamb. After easing the interior stop away from the jamb, he uses a pry bar to pull it off completely. The goal is to remove it intact. Old houses were built of excellent long-lasting materials, so an objective Is to save as much as possible.

• Once two of the sashes are removed and placed on a suitable work surface, Kolleen and Bill get to work on restoring the sashes (figure A) so that they can later be reinstalled. The basic steps in the process are summarized below.
  

• Restoration of the removed window sashes requires removal of the old glazing. In our case, this was achieved using a deglazing tool (figure B), a specialized chisel with a pilot bearing on the back side. The bearing can be adjusted for cutting the precise depth required for removing the amount of glazing present.

• The tool is held at about a 45-degree angle to carefully remove the glazing bit by bit (figure C).

• Note: The infrared paint-removal system used to remove paint from our window sashes (see below) can also be used in this application to simplify removal of old window glazing. The infrared tool is used to heat up the glazing so that it softens, taking on a clay-like consistency. In this soft form, it can then simply be lifted out rather than having to chip or scrape it.

  Figure B

  Figure C

  
  

  	Figure D
  	Figure E

• Strip the old glazing and paint as required to remove the old glazing points -- small pieces of metal placed every six inches or so in the frame to hold the glass firmly to the sash. The points are covered by glazing compound. The sharp tip of a paint scraper can be used to carefully remove the points without damaging the glass.

• Remove the original glazing points and then carefully remove the glass from the sash. Clean and store it for reuse.

• With the glass removed, our restoration expert used a specialized tool known at the Speedheater 1000® Infrared Paint Remover from Eco-Strip® to help in the removal of paint from the windows. This system uses infrared heat, at relatively low temperatures, to soften and loosen the old paint (figure D) The process causes the paint to separate from the wood so that it can easily be removed using a paint scraper (figure E). Aside from making the job of stripping paint faster and easier, this system is designed to be safer and more environmentally friendly than traditional methods. There is less chance of generating harmful fumes (as when a heat-gun is used) or paint-dust (as can be the case with "dry-scraping" and sanding). This can be specially important when removeing old paint which may contain lead. (More information about this special tool is included under "Resources" below.)

• Clean and and the sash surface. (If you use an infrared paint-remover as described above, sanding to remove paint may not be necessary.)

• Scrape the glass channel completely clean.

• If necessary, apply polyester-resin wood filler to any rotted areas. Allow it to cure according to the manufacturer's instructions, then sand smooth.

• Prime the applicable faces of the sash with an oil based primer.
  

• With the old paint removed, and the wood cleaned up and repainted, it's time to prep the sash before the old glass can be put back in. A back bedding of window-glazing that will sit on the inside of the window gives an extra seal for the glass. Apply a bead of the glazing to the inside of the frame (figure F) on all four sides. The excess will be cleaned away once the glass is installed.

• With the glazing applied, carefully set the glass back into the sash (figure G). Set the glass into place carefully and press into the back-bedded window sash. Make sure that the glass is seated securely all around the perimeter.
  Tip: Use the blade of a putty knife, rather than the tips of your fingers, to help carefully lower the glass into the frame.

  Figure F

  Figure G

  
  

  Figure H

• Using boiled linseed oil, lightly brush the inside of the glass channel on the vertical surface only and allow it to penetrate (figure H). Linseed oil conditions the wood, making it more receptive to creating a bond for the glazing compound.

• Using a latex based window glazing compound, place a bead around the inside of the glass channel.

• Using glazing push points or glaziers points, set the glass into wood spacing them at approximately 8-10 inches apart around the whole perimeter.

• Using an oil based glazing compound, carefully roll out thin strips of glazing compound and press them into the glass channel around the perimeter of the glass.

• Carefully strike off the additional glazing compound around the perimeter using a putty knife or glazers knife at an angle.

• Clean the sash and prepare it for reinstallation.
  

If the sash is so worn and damaged that it needs to be disassembled and strengthened before reinstallation, here are some tips:

• Using a nail punch, carefully drive the nails in each corner of the sash out. Carefully disassemble the sash rails.
  
• Reassemble the rails and glue each of the corners with polyurethane glue and re-square the window as required.
  
• Using a ¼" drill bit, carefully drill holes into the corners. Using ¼ dowel, place it into the hole with a dab of glue and trim to fit.
  

Table saw
Compound miter saw
Thickness planer
Belt sander
Random-orbital sander
Speedheater® infrared paint-removal system
Extension cords
Pneumatic finish-nailer
Pneumatic brad-nailer
Air hoses
Air compressor
Heat gun
Chisels
Ladders
Putty knives
Glazing knives
Carbide scrapers
Bar clamps

Materials used in this episode:

Double-strength glass, cut to fit if required
1 gallon glazing compound
Glazer's push points
Boiled linseed oil
Latex window compound
1 gallon two-part polyester resin
Cotton/Polyester blend rope, 1/2" diameter
Oil-based primer
Sandpaper – 80, 120, 220-grits
Exterior latex caulk
Poplar or pine stock for new parting bead

Safety Alert: Always wear eye protection when working with power tools or pneumatic tools.

Note: This is a summary of steps included in the procedures shown in this episode of Restoration Realities. There may be variations in procedures for your particular restoration project based on the types of materials you select and the nature or extent of your particular project. Always follow proper safety precautions, and read and follow manufacturer's guidelines, diagrams and safety notices that come with materials or products that you select.

RESOURCES :

Renovating and Restyling Older Homes: The Professional's Guide to Maximum Value Remodeling
Author: Lawrence Dworin
Publisher: Craftsman Book Company
ISBN: 1572180293
Order this title from Amazon.com.

Selecting and Renovating an Old House: A Complete Guide
Author: United States Department of Agriculture
July 2000
Publisher: Dover Publications
ISBN: 0486409562
Order this title from Amazon.com.

Speedheater Infrared (IR) Paint Remover
from Eco-Strip, LLC
The Speedheater Infrared Paint Remover® is a specialized tool for stripping paint or varnish from painted surfaces -- such as exterior facades, windows, doors, wood detailing and other forms of carpentry -- in a safe and environmentally responsible manner. This advanced paint-removal system uses infrared heat to soften paint for faster, cleaner and safer paint removal. It is also helpful for aiding in removal of paint in tight or hard-to-access areas. When used properly, the Speedheater loosens the paint so that it requires little scraping and no sanding for removal. In addition, this system offers a number of specific user and safety benefits: It reduces the need for chemical strippers and other toxic materials. It helps to avoid situations that could produce dangerous lead-dust or lead-gas when removing lead-based paint from old surfaces. It operates at a lower, safer temperature than that of an ordinary heat gun. It saves time and requires less work than some other forms of stripping such as use of a power-sander or heat gun. For more details on this tool and related products, visit the company’s web site:
www.eco-strip.com