Repair Windows (not the OS)




Introduction: Repair Windows (not the OS)

About: Electrical Engineer

If you have those old wooden windows, which haven't been painted and refreshed for a loooong time and you don't want to or can't buy new ones (which is a big investment)...maybe it is time to get things into your own hands and get the most you can from the old windows you have.

This instructable is for those that haven't done this ever and are thinking about windows repair inside the house.

Step 1: Prepare for Repair

First, scrub that old paint where it started to fall off. You don't have to scrub all of the paint, leave the old paint if it is firmly attached to the wood. Also remove pieces of wood if it started to chip or if the wood is soft (destroyed by the moist).

On old windows you will probably find that old caulk (window sealant made of clay and linseed oil) somewhere it will have cracks and somewhere it will fall off from the window. Remove the caulk if it started to fall off, but you can keep it even if it has cracks as long as it holds nicely to the wood and the glass.

In the end of this step your windows will look even more ruined than at the beginnig - that's good.

Step 2: Stucco, Sand, Caulk and Tape

In this step you repair the damaged parts by applying stucco with a plastic or metal spatula. Try to make nice surface as you will have less work sanding it later. You can apply stucco also to the cracked caulk that you decided to keep.

The stucco drys about 2-3 hours, except on those places where you applied a lot...I usually let it dry for about 6h. After drying, sand the rough surfaces with fine granulation sandpaper (I used 250 granulation).

Put new caulk where it is missing. I use the same old type of caulk (linseed and clay) but probably there is some new type maybe if you don't want to wait to dry (i think it needs around 10 days to harden and even a month to fully dry...but you can use the windows it doesn't matter if it's not dried). For applying caulk you can use spatula or your fingers (if you are a PRO like me).

Protect the glass before painting with tape and than clean everything. You can use wet cloth to wipe everything nicely especially dust and dirt, everything else will be covered by the paint.

Step 3: Painting

On the end you're ready to paint the windows. I used ordinary oil-based white paint, applied once, then waited 24h and applied one more coating of paint.

You can also paint the outside sill, the oil colors can also be used on metal surfaces.

I also painted the caulk although you shouldn't do that before it dries out, but i didn't want to wait 10days. The problem when painting fresh caulk is that the paint will take a long time to dry and it can sometimes form creases...but I painted it in really thin layer so i didn't had that problem. It doesn't matter if the paint on the caulk is still fresh, you can close the windows and they can get wet (the paint is oil based, also the caulk).

After all, if doesn't turn nice and you don't like it, repaint the caulk when it dries.

The end result is really impressing if you consider how the windows looked.



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    13 Discussions

    I think what you are calling "stucco" would be refered to as "Wood Filler" iIn the US and comes in several formats. You can also use BONDO (yes-the same as you use for your car!) just make sure with ANY filler you take ALL of the bad wet rotted wood OUT and carve or dremel or sand down to GOOD solid wood BEFORE you start with the fill job. Some you will need to do in thin layers to build it up to the proper level; if put on too thick it will not dry right and just fall out. Then you sand etc as in your 'ible.

    I think I had the SAME windows you have--and in about the same state of neglect; one bottom wood section where it held the glass in cracked and the glass pane fell OUT of the window---what a mess!

    IF you can't fix the windows or there are large gaps between the frames and the window casings--when it is BELOW freezing wet rags and push them inbetween the casings into the gaps---make sure this makes a seal--and let FREEZE. This makes a seal between the two parts and will help keep drafts out until you can fix or replace. Also those plastic window cover kits DO work but the less they need to BLOCK the better they will work to make a dead-air insulation area. There was a recent INSTRUCTABLES on how to use bubble wrap to cover windodef going to be using THAT 'ible!!!

    3 replies

    Thanks, your post covers something I didn’t. I just rewrite "stucco" from the box, probably they didn’t knew a better name also. I haven’t heard about freezing the windows, but wouldn’t that destroy the paint? I have seen the bubble wrap repair ’ible but I don’t like the idea not to be able to look through a window (that really takes away an important property of a "window" ;) )

    I don't think the freezing rag would hurt the paint--but if your window has that large a gap in it the paint is the least of your worries! This is for where there is a LARGE gap--say--over a few mm's or 1/8th of an inch or more--this doesn't sound like much but is enough to let a LOT of freezing air in. This would be between the top if the window PANE area and the CASING---

    You should also check the area on the EDGES of the window where the frame covers; often that area has NO insulation and is letting in a LOT of cold air. Prying--carefully!--the casing off and looking behind can give you an idea of what you need to do--put some foam insulation or the small rolls of fiber work there too.

    For the bubble wrap--I think that I would use this on a window where you are not looking out of it all the time---we have several that we coujld do this on because we are not realy using them in the winter. We also have WINDOW QUILTS on several--a large sliding door and the small basements ones--these are a form of bubble wrap bonded to fabric with Velcro on the edges to seal them to the wall or window frame. If you can't find this stuff you could make a "pillow case" for bubble wrap and use that.

    You're right there, a good insulation on the edges is a MUST. I'm waiting for cold days i.e. I'm lazy. But I remember we used to check for air draft with a candle or lighter, bring it close to the edge and the flame shows really nicely if there is a draft :D

    What is your recipe for clay and linseed oil putty? Ratios? Added ingredients? Mixing procedure? Source for clay? Type of clay? Type of linseed oil, raw or boiled?

    1 reply

    I bought it, in Serbia you can still buy 100% natural clay and linseed oil putty for some ridiculous price (something like 2$/Kg). Sorry but I really didn't pay any attention to read the mixture ratio.

    Very nice instructable, thank you!

    If your old windows are being replaced by your landlord (there is a nice song about landlords by the Dead Kennedys that pretty much sums up my opinon about this special kind of humans), you can still try to talk the Window-mongers into letting you keep the old Windows and build a nive greenhouse (nice collection here: ).

    does anyone know if it's possible to replace seals in 2 pane windows?

    1 reply

    I think it is possible, the sealant depends on the materials. If your windows are from aluminium or PVC you can use regular silicone sealant. The silicone is applied from a tube (like a big syringe) and then you smooth it with your finger. The smoothing is tricky, you should spit on your finger before touching the silicone, do it in one move and wipe your finger with paper towel every time you draw a line.

    Wow, such a dramatic difference!

    What computer did you use jk great project

    I am moving to a farm this weekend, and almost every window needs a repair.. So this was just perfect! Thanks :)

    Excellent job. Thank you for sharing this great project!