Go Back  DoItYourself.com Community Forums > Interior Improvement Center > Doors, Skylights and Windows
Reload this Page >

Refinishing water damaged interior wood window sash

Refinishing water damaged interior wood window sash


Old 08-05-19, 05:45 PM
Thread Starter
Join Date: Apr 2008
Posts: 7
Received 0 Votes on 0 Posts
Refinishing water damaged interior wood window sash

Hi everyone! I recently bought a 40 yr old home with wood windows that are painted on the outside but have some sort of thin satin clear topcot on the interior side of the windows. Many of the windows are casement and the lower portion is gray and stained, possibly water damaged. The wood is overall in good condition (no rot) but discolored and somewhat stained. The upper part of the sash that isn't as exposed to the elements is still in great condition and the topcoat is intact.

What is the right way to seal and refinish these? I have no idea whether these are stained or just clear coated somehow and don't want to go on a fool's errand of trying to match stains, nor do i want to refinish the entire sash AND the interior casing to match just because the lower portion is damaged. At this point i'm fine with the lower portion staying gray if it has to be that way, but i would like to seal it and protect it from further damage. I'm concerned about sanding out the gray stained portion and subtly altering the shape of the sash and introducing drafts if the window doesn't fully "seal" when closed.

What's the best product to use here? The guy at Sherwin Williams recommended Minwax Polycrylic water-based coating, but i've heard this requires 3-4 coats for a fairly flimsy coating. That said, it is an interior portion of the window and shouldn't really be getting wet so maybe i don't need a hardcore oil-based exterior product? I'd prefer water-based for ease of cleanup but really just want some help on what is the easiest reasonable fix for these windows.

I'm also considering using a wood preservative like Woodlife Classic before putting on the topcoat -- maybe that would let me get away with using a water-based polyurethane? I'm going to be using the Woodlife on the exterior of the windows before the new paint goes on so i'll have it around.

Thank you for your help!

Name:  w1.jpg
Views: 35
Size:  91.8 KB

Name:  w2.jpg
Views: 34
Size:  135.3 KB

Name:  w3.jpg
Views: 37
Size:  102.2 KB

Last edited by PJmax; 08-05-19 at 07:54 PM. Reason: resized pictures
Sponsored Links
Old 08-05-19, 06:10 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 23,123
Received 194 Votes on 180 Posts
I would suggest you use an orbital sander (with 120 grit only) on the wide portions of the sash... and then do hand sanding on the portions that butt up to the glass. (again with 120 or 150 only, or with a sanding sponge which is good for contours). I would not recommend using your wood preservative on anything interior (it says its an exterior product) as it could possibly seal the wood preventing it from accepting interior oil stain. (from the looks of it you will need a light stain to give the wood some color.) Its an exterior product so when they say in the directions that it will accept paint and stain after 24 hours, its not the same kind of stain you use on interior wood- so those directions do NOT apply to interior work, and IMO it should not be used inside.

If you want to know how the wood will look when it has a coat of clear finish on it, just wet a paper towel with paint thinner and wet the wood. The wet look is what color it will be with a coat of clear polyurethane on it.

Personally I would not use a water based product. Oil based poly is very easy to use and very easy to clean up (with regular paint thinner- not the low voc stuff). Oil based products will usually last longer and stick better. Your interior is probably doing that because of moisture in the winter months (poor glass + cold temps + high humidity) So it's a safe bet it will happen again.
marksr voted this post useful.
Old 08-06-19, 02:48 AM
Marq1's Avatar
Join Date: Sep 2016
Location: USA MI
Posts: 4,334
Received 94 Votes on 85 Posts
My suggestion is to not use Minwax, its not a really good product. Check out the brand General Finish at a Woodcrafter shop, excellent products that will outlive Minwax.

Personally I have given up all oil based products years ago as the tech of water base has advanced and I have never been disappointed to date using GOOD products!
Old 08-06-19, 02:55 AM
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 46,066
Received 120 Votes on 107 Posts
Bare wood requires 2-3 coats of poly - it doesn't matter if it's water or oil based. Oil base is more durable although it shouldn't make much difference on windows. Oil base will deepen the colors in the wood/stain some and will amber with age. Water base doesn't affect the color any other than give it a sheen. I prefer the look of oil base poly.

Condensation is the main cause for the damage, the best way to prevent a reoccurence is to recoat the poly sooner.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes
Ask a Question
Question Title:
Your question will be posted in: