Best Linseed Oil Putty for Sash Windows: 2025 Expert Review
DR Joinery
Expert Joiner & Restoration Specialist
Glazing a sash window isn't just about slapping some filler in cracks. In historic properties, specifically the Victorian and Georgian terraces we see so often, the putty is the first line of defence against weather. If it cracks or lifts, water gets behind the glass, and before you know it, you're looking at expensive rot repairs.
Many DIYers make the mistake of using modern silicone or acrylic sealants on timber sashes. This is a disaster for longevity. Timber moves with the seasons—expanding in winter damp, shrinking in summer. Traditional linseed oil putty moves with the wood, whereas modern sealants often debond or trap moisture.
In this review, I'm looking at three linseed oil putties I've used on site. We'll look at a budget-friendly pot for standard repairs, a high-quality bulk option for full renovations, and a handy size for those quick problem-solving patch jobs.
Live in York?
Have your sash windows seen better days?
Get a free quote from our local team.
Specs vs. The Real World
The Spec: "Drying Time Claims"
"Most tubs say 'Ready for painting in 7-21 days'."
In our damp local climate, I rarely paint over putty within two weeks. If you paint too early, the oil bleeds through and ruins your finish. I advise leaving it until a firm skin forms, which can take up to a month in a cold York winter.
The Spec: "Does Not Crack"
"Manufacturers claim flexibility prevents cracking."
Putty only stays crack-free if the timber rebate is properly primed (but not too glossy) and the putty is thoroughly kneaded before application. If you skip the prep, even the best putty will fail.
My Top 3 Recommendations
Three options to cover different needs and budgets
Everbuild 101 Multi-Purpose Linseed Oil Putty – Suitable for Single Pane Glass – Natural – 1kg
Everbuild
This is the standard 1kg tub you will find in most joiners' vans. At under a fiver, it represents excellent value for money and provides enough material to re-glaze a standard sash window comfortably. It mixes well and has a reliable consistency.
The Good
- Excellent price point for a 1kg tub
- Classic natural colour accepts paint well after curing
- Good adhesion to primed timber rebates
The Bad
- Takes a considerable time to skin over in cold weather
- Must be thoroughly kneaded to mix the separated oil
Installer Tip:
This putty contains a plasticiser for adhesion. Before you start, take a handful and knead it in your warm hands for at least two minutes. If it feels too oily, roll it on a piece of cardboard or newspaper for ten minutes to leech out the excess oil before applying.
Priced at £4.95 at the time of writing
Check Price on AmazonCut360 Linseed Oil Putty, 5kg, Single Glazing on Windows with Wooden and Metal Frames
Cut360
If you are tackling a full property renovation or restoring a large bay window, this 5kg tub is the professional's choice. Made with Bavarian mountain chalk, the texture is notably smoother and less gritty than cheaper alternatives, making it easier to get that perfect chamfered line.
The Good
- Superior smooth texture due to high-quality chalk
- Bulk size is economical for large projects
- Excellent thermal resistance (-30°C to +80°C)
The Bad
- Large tub can dry out if not sealed perfectly between uses
- Higher upfront cost if you only have one window to do
Installer Tip:
Because this is a large tub, you likely won't use it all in one go. To prevent the remaining putty from forming a hard crust, pour a small layer of linseed oil over the top of the putty in the tub before sealing the lid. This keeps it moist for months.
Priced at £23.32 at the time of writing
Check Price on AmazonEverbuild 101 Multi-Purpose Linseed Oil Putty – Suitable for Single Pane Glass – Natural – 500g
Everbuild
Whilst technically more expensive per kilo than the 1kg version, this 500g tub is the ideal problem-solver for the occasional repair. It is perfect if a football has gone through a single pane and you don't want a large tub of putty going hard in your shed for the next five years.
The Good
- Small size reduces waste for minor repairs
- Easy to mix the entire contents at once
- High quality plasticised formula resists cracking
The Bad
- More expensive per unit than the 1kg tub
- Not enough product for a full sash restoration
Installer Tip:
When replacing a single broken pane, ensure you thoroughly hack out the old, hard putty. Apply a coat of primer to the bare wood rebate and let it dry before applying this new putty; otherwise, the dry wood will suck the oil out of the putty, causing it to crumble prematurely.
Priced at £6.00 at the time of writing
Check Price on AmazonFrequently Asked Questions
How long does linseed oil putty take to dry?
Can I use decorators caulk or silicone instead of putty?
Why is my putty cracking after a few months?
Do I need to mix the putty before use?
Is it worth restoring old sash windows or should I replace them?
Need Professional Sash Window Restoration?
Our team at DR Joinery specialises in Sash Window Restoration across York.
Get a free quote for professional installation.
View Our Sash Window Restoration Service