After all the hard work is done restoring a wood window, there is one final step: painting your window sash. Painting a window is by far the most important part of the process because it protects all the work underneath. It keeps sun, rain, dirt, insects, air and anything else from harming your window.
Without paint, glazing putty is no good after only a couple months, the sun’s UV rays begin breaking down the wood fibers of the window immediately, water will cause corrosion of your glazing points.
Without paint, your window will fail quickly. But you already know that you have to paint your windows, right? Maybe so, but there is a very specific way that historic windows should be painted to both protect their parts AND ensure smooth operation.
Here are my 5 rules for how to paint a wood window sash.
1. Don’t Paint the Sides
The sides of the sash that slide up and down in the jambs should be left bare. No primer and no paint. This may sound odd, but it has been in practice for well over 200 years. These areas are not seen or readily exposed to the elements so there is no cosmetic reason to paint them, but there is a more practical reason NOT to paint them. By leaving these areas bare you allow both rails (horizontal parts of the sash frame) and both stiles (vertical parts of the sash frame) to expel moisture.
With these sections bare, the entire sash is able to dry out if it should happen to get wet. Bare wood breathes much, much better than primed and painted wood.
In addition, these parts of the sash slide against the window jamb and if they are coated with paint (especially latex paint) they will stick and be extremely difficult to open and close. Leave it bare.
2. Don’t Paint the Bottom or Top
For the same reasons as above the top of the upper sash and bottom of the lower sash should not be primed or painted either. These parts are not visible when the window is closed and therefore not exposed to the elements. Again, this will aid in the window’s ability to dry out. Not much else to say about this, so let’s move on.
3. Use Oil-based Primer
For the best performance use an exterior oil-based primer. I prefer Kilz Complete in my shop because it is hides very well, goes on easily and sands down nicely. The sash should be primed and lightly sanded with 220-grit paper to smooth out the surface before installing the glazing putty.
Use a brush and work the primer into the wood. Spraying on primer is fine, but be sure to work it in with a brush as you spray. Brushing ensures a better bond between the wood and primer than spraying alone.
4. Apply 2 Coats of Quality Paint
Whether you decide to go with oil-based paint or water-based doesn’t matter to me. The point is the get at least two coats of paint on the inside and outside. Don’t skimp on this paint either. Use a top-notch enamel paint. I prefer Sherwin-Williams Porch & Floor because it is an easy to work with water-based paint and since it is formulated for floors it gets very hard, very quickly.
The technique for painting your window sash is difficult to describe in a blog post, so I’ve put together a short video to show you how it should be done.
Check out the video below and don’t forget that you can get more videos like this by subscribing to our YouTube channel.
5. Finishing Up
Once the windows are painted let them sit aside and cure for at least a few days. This may sound pretty elementary and I’m sure you would never try to put windows with wet paint back in, right? It’s not about the windows being dry. It’s about the paint having time to cure.
Water-based and oil-based paints can take up to 30 days to fully cure. Until that time the paint is more prone to being damaged by scuffs, knicks, and water. Don’t try to wipe down new latex paint or clean it until that 30 days has passed. Otherwise, you run the risk of messing up your paint job.
Once the paint is cured, enjoy the finished product by opening those windows as much as you’d like. You deserve it!
If you have more questions about the rest of the process of restoring a wood window visit my resource page How To: Repair Old Windows
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I love old houses, working with my hands, and teaching others the excitment of doing it yourself! Everything is teachable if you only give it the chance.
Hi Scott,
I love all of the great information on your site! Also, your Old Windows Made Easy book has been awesome… I have seven windows that I am restoring and have recently decided to stain/oil the inside instead of painting. I cannot find any information about what I should do to the window jambs, though. Should I stain the entire window jamb and parting beads? Will this look funny from the outside? The outsides of the windows will be painted white. Should I also paint or just prime the part of the jamb that will show outside? I’ve also considered just oiling the jambs and only staining/oiling the sashes and trim inside. I would appreciate your input! fyi – I am using Heritage Natural Finishes Concentrated Finishing Oil over the stain.
Is it ok to paint the top of the inside (bottom)sash and the outside (top) Bottom since its exposed to weather?
Rick, painting the tips and bottoms isn’t he end of the world either way, but several tests have shown that leaving the top of the top sash and bottom of the bottom sash helps the windows moisture levels within the optimal range.
Hi Scott,
Thank you for great information. I’m in the process of restoring my double hung wood sash windows and have been reading your web site as a bible :).
I have a question about painting the window frame hope you can help. How do you advice the best way to paint window frame? Which parts should paint and what parts should I leave bare?
Catherine, there are a lot of regional differences in how the jamb was painted. Down here in Florida I usually paint all parts except for the parting bead which I leave with only an oil-based primer. That seems to help keep the sash from sticking.
Great article! Would you paint the parting bead In a double hung window?
I usually don’t paint he Parting bead since it can result in sticking sashes, but I think it’s personal opinion.
Scott,
How do you feel about Allback linseed oil paint? Their entire system strikes me as very compelling. Your thoughts…?
I have used their system a little bit and am doing some testing down here in Florida before making any final decisions about whether it should become part of our offerings.
I love this site, restoring windows has changed the way I think about a lot of stuff related to maintenance and how to do it sustainably. Two questions/comments:
-would like to see articles about how to set up a shop, things like work tables suited for stripping and de-glazing. I see you use an easel for the painting? I find these things to often be a make or break element of restoration projects
-I’m also eagerly waiting for advice on linseed paint! Have 26 double hung sashes that nee a new lease on life.
many thanks!
Larry, thanks for the ideas. I’ll try to put together some posts on shop setup and work techniques soon.
Referring to your item #3, using an oil based primer. I’ve spent the afternoon trying to find KILZ Complete here in Ventura, CA and it seems that hardware stores here and even Lowe’s and Home Depot don’t/can’t/won’t carry it. HD will ship it to me, but nothing in stores. All other KILZ products are readily available. I already have both KILZ Latex and KILZ Premium from other projects. Would either of these be sufficient, considering the difficulty I am having finding oil based primer? (All other reviews I have read of KILZ Complete haven’t been so favorable either) I really have no complaints using the water based Latex in the past…but this project, reconditioning 3 wooden windows on a south facing wall – harsh sun and elements and about 3 blocks from the beach, so occasionally salt air…I do plan on using the Sherwin-Williams as you recommended.
Patrick, California Paints makes a good exterior oil-based primer too which should be available near you. Any exterior grade oil-based primer will do the trick. For wood windows stay away from latex primers.
Scott,
Thanks for your quick reply. Sadly, California Paints is in Northern California, about 8 hours driving from here, and California has insane smog laws barring shipment of oil based primers. One of the Home Depots nearby has KILZ Complete in Quart cans (obviously not enough). They cannot order Gallons because KILZ Complete cannot be shipped to California. Bottom line is, the laws have made it really hard to get/use oil-based primers in California. I could have a friend who is going to visit soon maybe bring it from out of state, but that is not a guaranteed. It appears that except for ‘remaining stock’ all that is available in California IS latex based primer.
There are other local stores that still have Alkyd/Oil based primers, including Sherwin Williams, but of course, they are more expensive and I do not know their quality. KILZ ‘Original’ is still available, and is supposedly oil-based, but I do not know if it is comparable to KILZ ‘Complete’.
I am just embarking on refinishing the windows on my 1919 Craftsman. I find your site spectacular ad invaluable; so much great reading and easy to understand, though I have a fairly easy grasp of these things which helps. I fully understand what you wrote about not painting certain surfaces of the sashes and why. My question is what should I do with the jambs? Paint or stain/sealer/lacquer? Should I only coat the area of the jamb that would be most often exposed to the elements? I like the bronze weatherstripping as well, but I don’t want to leave the wood untreated but I want it to be done accurately and properly…the window I started this project on did not have much paint in that area so dismantling the windows was a snap. Now I just happened to glance up and see an answer you gave on Feb 17, 2014…but if there is anything more you can add it is much appreciated.
I recently restored one of my 2nd story windows and put high quality storm windows in. Oil based primer, 2 coats exterior paint outside, 2 costs interior paint inside overlapping glass 1/16″. I get condensation on the inside especially when blinds are closed. I have been faithfully wiping dry each morning. After only 1 month I am already seeing cracks in the paint on the inside bottom rail of the bottom sash. Ticks me off ’cause it was a lot of friggen work and I have more windows to do! Maybe I should replace the glass with dual pane. I don’t want to end up re-scraping and re-painting every two years!
Maybe I should use exterior paint on the inside too?
I would use exterior paint on both sides of the sash.
Dan, what part of the country do you live in? Do you notice condensation in other parts of the house? 1st story windows as well have condensation? A lot of this is house specific and it may take a professional inspection of the house to remedy the moisture issue.
Paint vs Stain/Varnish/Lacquer…is this just personal preference, or is it advised to paint double hung windows? my 1923 craftsman has all natural wood windows and doors, but the only PAINTED windows in the house are the double hung? I didn’t know if this was previous owners idea, or is there some reason for this?
On the interior, paint or varnish is just personal preference of the original owner. Might be fun to do a little digging and see if the double-hungs were originally varnished too.
i just want to clarify, you prime with oil primer, and it’s okay to paint over that with latex paint? I’ve always heard the oil primer would “reject” the acrylic latex, and not create a bond.
Courtney, latex over oil-primer is not only ok to do but it is considered an industry “best practice” for painting wood.
Scott,
I found your video about painting sashes very helpful. One question: the video covers the exterior (i.e. glazed) side. In particular, you emphasize (as other sources do) “lapping” a thin fillet of paint from the glazing onto the window glass, to provide a seal. Makes lots of sense for the exterior. How about the interior side? There’s no glazing, and certainly fewer issues of water pentration. Is it necessary or recommended to lap paint between the wood muntin and the glass. (I’m talking old-style single glaze sashes.) Or is it ok to scrape off any paint on the interior side of the glass back to the muntin?
Thanks!
Noble, yes you should still lap the paint onto the glass ever so slightly on the interior. There is a small bed of glazing putty there and to protect the sash from condensation in the winter the paint should go onto the glass about 1/16″ or so.
Well, I’ve just managed to get my 100-year old casement window open, but I can’t get it open enough to expose the horizontal piece on the top sash (the one just under the lock) in order to scrape, prime, and paint. It looks pretty bad–peeling and flaking,etc. What can I do? thanks!
I recently bought a craftsman house built in 1908 that has all the original windows. so I have lots of glazing to do. I want to restore this house to its original beauty and was curious about staining the interior of the sash instead of painting. I can not seem to find any information on painting the the outside but not the inside.
Josh, we do a lot of windows that are stained on the inside but painted on the exterior. If you are planning to fully restore the windows I recommend that instead of priming the glazing rabbets you either use shellac or Boiled Linseed Oil before glazing. That way you don’t get any primer runs onto the inside of the sash. Once it’s glazed you can prime the outside and stain and poly the inside. Also, use a spar urethane for the interior which will hold up to the UV and moisture better than regular polyurethane.
I am redoing the wood storm windows for my 1923 Craftsman bungalow. I stripped the paint, removed 90% of the glaze but decided to hand off for the rest of the removal and the reglaze. They didn’t prime before they reglazed with DAP33 compound. I am sick. The company is a reputable glass dealer in town. What do I do? I already have paid out dearly for them to do the work. Thank you.
Joan, though I don’t use DAP 33 I do know that the manufacturer requires wood sash to be primed with an oil-based primer prior to glazing. I would contact the company and have them redo the work correctly as per the manufacturer’s recommendations. They should have known how to properly apply the glazing putty if they took on the job.
Thanks Scott. I had called them before contacting you but was told they have always done it this way and have never had a problem. I also contacted their competition and was told the same thing. They don’t prime or linseed oil because of the dry time. It is a minor part of the business for both of them. They will not redo them. Lesson learned. Don’t assume that because they are the “professionals” that they are going by the book.
What are your thoughts on a push-out casement window? Should the sides, top, and bottom edges be painted or left bare? My originals were painted, but they were also damaged slightly by rot on the bottom corners.
We usually prime and paint all sides of casement windows since that was typically the practice for decades. I’m still doing some testing to determine what is best, but for now I haven’t had many issues with this technique.
Great turorial Scott. I am in the process of restoring a large bay window and have removed the center picture frame for reglazing. It is now stripped down to bare wood and I have a question about painting the interior-facing side. Should it be completely top coated prior to installing glass or will the putty that oozes out of the rabbited area interfere with the painted surface? I’d hate to wait 30 days for the interior side to dry before tackling the glass installation.
You’ll wanna seat the glass and wait a few days till the putty is skinned over to paint the interior. Lap the paint onto the glass about 1/16″ on the inside as well as the outside to keep the putty from failing prematurely.
Scott – great article – I am undertaking the task of redoing 1935 double hung windows & some perhaps 1960/70 wood ones on the top floor. I’m in a historic district but the house was vinyl sided before I bought it and the windows wrapped with vinyl/the old windows were left in except for a side porch window. I’ll have to paint these in place/not removing them but I am at a loss on a few things. It appears I should abandon my plan to use Zinsser 1-2-3 primer & instead use oil primer. Not cool. But I will do it if that is necessary/I am presently removing years of old glazing compound/botched paint jobs and repairing wood. There are storms on the windows as well that I have removed screen and glass wise but the alum frames aren’t coming off – in some cases, the siding overlaps them – sigh. My question is should I paint the windows (sashes) to match the horrid vinyl wrap around them or should I contrast slightly? Any help or thoughts appreciated. I wish I could afford to have this done but really don’t have the money at this time to have a pro do it & I can’t let the windows deteriorate any further. They seriously need reglazing and paint. Thank you!!
I think folks need to hear how critical prepping the wood for repainting is to the renewed life of the window. If the old, dry paint is not completely removed, the new paint will not stick well and fail soon. Stripping paint with chemicals or steam drives moisture into the wood. It takes extra days to neutralize and dry this wet wood. Infrared heat Speedheater works by softening the paint with low heat so the paint scrapes off easily. The bare wood is ready immediately for priming and painting.
How do you handle sash tracks that have been painted? Do you strip them to help with ease of raising/lowering? How about any other lubricants or waxes in the tracks? Thanks!
We scrape all the old paint from the jambs the prime with oil-based primer and repaint if requested. Usually I prefer to leave the jambs just primed so they don’t bind.
Best thing I ever did for my 1926 windows was to get storm windows. Also these old windows if kept rot-free are MUCH superior and more economical to repair that so-called double-glazed windows. Double-glazed windows are horrifically expensive and have a 100% failure rate.