Glazing and Linseed Paint at Home

North House leaves glazing for home. Seal the rebates, bed the glass in linseed oil putty pressed to about a millimeter, fix it with sprigs, face-putty at a bevel, and paint the putty with linseed oil paint lapping a millimeter or two onto the glass. Why sources disagree about shellac in the rebate, and how often to repaint.

3 min
6 steps
2 questions
Lesson 122 of 204

In this lesson

Prepare the rebate
Glaze
Paint
Care
Try it

What you need

Material	Qty	Where to get it
Linseed oil putty	About 400 g	Allbäck US store
Glazing sprigs (points)	4 per pane	Hardware or glazing supplier
Linseed oil paint	1/2 liter	Solvent-Free Paint (Earth+Flax), Rochester, NY
Shellac or linseed primer	A small can	Paint store
Whiting (chalk) and pumice optional	A little of each, for cleaning glass and stiffening putty	Solvent-Free Paint (Earth+Flax), Rochester, NY

Tools

Putty knife with a stiff blade
Small hammer or a point driver for the sprigs
Artist’s brushes for painting the putty line
Glass cutter, straightedge, and gloves, if cutting your own glass

Checkmarks are saved on this device.

The class sends the window home unglazed, with guidance for finishing it ¹. Norwegian windows set the glass in a putty rebate without wooden beads ², so glazing is putty work.

Prepare the rebate

The bare wood of the rebate needs sealing so it doesn’t suck the oil out of the putty. Sources disagree on what to use:

Riksantikvaren primes it with thinned linseed oil paint ³.
Allbäck’s instructions say to shellac the rebates first ⁴.
NPS Brief 9 says to prime wood before glazing compound goes on ⁵.

Thinned linseed paint is the most traditional and compatible with linseed putty; let it dry before glazing. Clean the glass with pumice and water ⁴.

Glaze

Knead the putty until it’s soft and smooth ⁴.
Press a thin bead of putty into the rebate all around.
Set the pane in and press it gently down until the bed putty is about 1 mm thick ³.
Fix it with glazing sprigs, small headless points, about two per side, pushed into the wood along the glass ³.
Press putty into the outside of the rebate and draw the putty knife along it at an angle, leaving a smooth bevel from the glass to the edge of the wood ⁵. Trim the excess bed putty from the inside.

How To: Glaze a Window In Place The glazing sequence, shown with American glazing compound; linseed putty is worked the same way. Credit: The Craftsman Blog · YouTube standard license · 7:15 · Source

Playback is optional. If the player is unavailable, open the video at its source.

Quick check

How thick should the bed of putty under the glass be after pressing?

Paint

Linseed putty can be painted right away with linseed oil paint, according to Allbäck ⁴; Riksantikvaren paints once the putty has dried a little ³. Brush the paint over the putty and a couple of millimeters onto the glass ³, sealing the joint against water. Don’t paint the hinge edge of the sash, or it will bind ³.

Traditional exterior colors for 19th-century Norwegian windows are dark, often brown or green ². Linseed paint goes on in thin coats.

Quick check

How far should the paint lap onto the glass?

Care

Oslo’s heritage office recommends repainting about every 5 years on south-facing walls and every 8 to 10 years elsewhere ². Wash, touch up any cracked putty, and add a fresh thin coat; linseed paint takes new coats well.

Try it

Glaze one pane, then wait a week before the other three. Watch how the putty skins and how the paint over it behaves, and adjust your bevel on the rest.

Lesson complete

Nice work.

1day streak

0/1today's goal

–correct

Up next · 4 min

The Norse Pram and What to Buy

Next lesson

Back to course Today

Sources for this lesson

1
Traditional Building: Norwegian Sash Windows. North House Folk School. verifiedNine days with a day off (May 4-12, 2027), instructor Thor-Aage Kaminka Heiberg (master joiner, head of NTNU's Norwegian traditional building crafts program); tuition $875, materials $180. Build a traditional Norwegian sash window in its casing with hand-tool joinery: first four days the sash from pre-milled stock, rails and stiles with a crossed vertical and horizontal bar, open mortises and tenons locked with pegs; next four days the casing from rough-sawn boards, planed straight and flat by hand, cut to size, a couple of strategies for the sash rabbet, dovetailed corners; all parts moulded with traditional sash profiles using planes the instructor provides. Students bring home a four-pane window; glazing is done at home. All tools provided; optional scrub, smoothing, jointer and block planes, saws, chisels, mallet, mortise gauge, plow and rabbet planes.
2
A. Korsaksel, M. Stige. Informasjonsark: Vinduer. Byantikvaren i Oslo. 2014. verifiedWooden-bar windows appear in Norway in the early 1700s; pre-war windows used sorted, slow-grown pine heartwood; glass set in a putty rebate without wooden beads; bars are true through-bars; repaint every 5 years on south walls, 8-10 elsewhere; linseed oil paint outside.
3
Vedlikehold av vinduer. Riksantikvaren (Norwegian Directorate for Cultural Heritage). verifiedPrime bare wood in the putty rebate with thinned linseed oil paint; bed the glass in putty, pressing until the bed putty is about 1 mm, fix with glazing sprigs, putty the outside, and once the putty has dried somewhat paint it with linseed oil paint, running a couple of millimeters onto the glass. Don't paint the hinge-side edge or the sash binds. Repair wood should be slow-grown, resinous pine (malmfuru). Hardware: corner irons and hinges, greased with petroleum jelly.
4
Allbäck Linseed Oil Putty. Allbäck US store. verifiedRaw purified linseed oil and chalk; knead before use; shellac the rebates first and clean glass with pumice; can be painted right away with linseed paint; 400 g $32.49 (2026).
5
John H. Myers. Preservation Brief 9: The Repair of Historic Wooden Windows. National Park Service, Technical Preservation Services. 1981. verifiedEvaluate each window: location, paint, frame and sill, sash (rails, stiles, muntins), glazing, hardware; moisture is the primary cause of decay, found at sills, sill-jamb joints, bottom rail corners, and muntin joints; test wood with an ice pick. Repair classes: I routine maintenance (paint removal, reglazing with a bed of putty, glazing points, beveled putty, sash cords, weatherstripping, paint lapped onto glass), II stabilization (dry, fungicide, boiled linseed oil, putty, or epoxy consolidation; slope patched surfaces), III splices and parts replacement. A staff member restored a 90-year-old two-over-two window in a few hours of work spread over several days of curing. Exterior storms are efficient and reversible. U-values: single-glazed wood 0.88-0.99, with storm 0.44-0.49, double-glazed metal without thermal break about 0.6. Pegged mortise-and-tenon sash come apart easily for repair. (1981 text: its heat-gun and paint-removal advice predates lead-safe rules.)