Defogging Windows


Old 12-01-16, 10:53 AM
Thread Starter
Join Date: May 2009
Location: USA
Posts: 207
Received 0 Votes on 0 Posts
Defogging Windows

The 14 large, double-hung windows on my first floor date back to 1995 (8 years before my ownership). Every one of those windows is fogged to a certain degree, with some having white "etching" or mildew/mold between the panes. Given that I plan to sell this house in 2-3 years, I realize the need to remedy this situation, but would obviously like to avoid the replacement cost.

I've read a little on the process of defogging through drilling a hole in the glass, injecting a cleaning, allowing to vent, and installed a check valve in the hole. Does anyone have experience with this process, positive or negative? Would a "handy" person be able to DIY such a fix? I have yet to search YouTube, but that will likely be my next stop later this evening.

Sponsored Links
Old 12-01-16, 10:58 AM
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 19,308
Received 47 Votes on 44 Posts
Doesn't work. These IGUs need to be replaced. FWIW, we replace about a dozen every year in our rental units, not a horrible DIY job.
Old 12-01-16, 03:14 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 23,129
Received 194 Votes on 180 Posts
It can work but it has to be done at the first sign of moisture... wait too long and the residue inside becomes permanently stained.

IMO most of those guys are snake oil salesmen. Replacing the glass is the only real solution.
Old 12-02-16, 05:12 AM
johnam's Avatar
Join Date: Jan 2000
Location: USA
Posts: 1,956
Received 3 Votes on 3 Posts
If you can't DIY, the cost could be high. Get a price on replacing the insulating glass units and the price of installing new windows. If you're selling in a few years, new windows is what a lot of buyers look for.
Old 12-02-16, 05:29 AM
Join Date: Oct 2008
Location: New England
Posts: 10,406
Received 23 Votes on 21 Posts
Well, 21 years isn't young, but IGU's are expected to last longer than that, especially when you say all (or most) have failed. You might contact the mfg to see if they are still under a lifetime warranty.

As a side note, here on the forum we deal with both sides of home ownership, those selling soon and those who just bought what they hoped would be their dream home. Unfortunately all too many of the new home buyers soon discover how many short cuts were taken to hide problems past the sale date. My recommendation agrees with the above, replace those units and document the work so you can justify a few extra dollars at sale time.
Old 12-02-16, 06:57 AM
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 19,308
Received 47 Votes on 44 Posts
With this many to replace, it might be worth trying to go straight to the manufacturer - we replace enough that we found one who would work with us so we get the IGUs at the same price as the glass store, so we save quite a lot of cash.

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: