fire damaging themopane windowseals
fretboor
| Posted in Energy, Heating & Insulation on
I hope to reclaim a whole bunch of wood windows from a cottage that was damaged by fire. Any body knows the effect of high to extreme high heat on the seals of thermopane units? The frames are dirty but other than that in very good shape.
Replies
the glass has beed tempered, morethan likely not uniformly..
risky business...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
Sorry, i do'nt follow glass is a regular not tempered unit what is the risky bussines part?
I think he's saying that the heat from the fire tempered the glass, but not evenly.
I won't be laughing at the lies when I'm gone,
And I can't question how or when or why when I'm gone;
I can't live proud enough to die when I'm gone,
So I guess I'll have to do it while I'm here. (Phil Ochs)
the heat from the fire tempered the glass, but not evenly.
subject to being fragile... and if they get sun exposure... subject to self destruction..
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
"Some days it's just not worth chewing through the restraints"
I think he's JOKING that the heat tempered the glass albeit 'not evenly' making such a concept very unpredictable. But I don't think you heat temper glass at such low temperatures and heat tempering would be done under some unique conditions (like controlling how it cools down as well).
wasn't kidding....
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
"Some days it's just not worth chewing through the restraints"
great for a greenhouse, no problemo..
reuse for a paying customer - youch
windows in my own house - youch
windows for a shed - good deal if free!
You did not say what the wood was like - any carbonization?? If the wood did not carbonize at all, I'd use them as soon as I'd use any thermopane.
Hmm ... maybe talk w/ a glazier. I'm guessing the temp inside near the windows didn't get too hot ... maybe 200 deg? Maybe somewhat more? If there was simply a fire in the house that resulted in significant smoke damage ... the primary damage, I'm assuming, as a large fire would have likely created significant window damage. Smoke damage could easily have occured in well under 150 degF temps. High and "extreme high" heat would not likely have allowed the glass to survive and would have shown more damage to the wood frames than "dirty". Just because there was a fire and smoke in the house doesn't mean high heat. While I/we have no idea of the extent of the FIRE damage (vs. smoke damage), I'm guessing dirty frames is mostly smoke damage.
Probably good to go. Worst case ... you find later that you have to buy replacement glass panes if they are found to be failed insulated units. Then you can buy the glass you really want (e.g. low-e, tinted, etc.). After thinking about it ... I don't really see the problem. If the frames are good, they are the major expense of the window.
draw some of yur own conclusions..
http://www.ehow.com/how_4796078_temper-glass.html
Amazon.com: The Behavior of Glass and Other Materials Exposed to ...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
Well your first link answers your own theory ... heating glass to 600 degrees will no doubt burn the wood frame holding it (combustion temp aprox 500 degF). I suspect it would curl the paint for sure and it may visibly damage e.g. a vinyl frame.
I'm surprised you found a like to 'do it yourself' glass tempering. Even the suggestion that the average person could do this using a kiln process surprises me. I'd think while the kiln/heating process is probably a piece of cake, the cooling process may be less so. Though I don't know about that. I'd think laying the glass on e.g. a concrete slab would end up w/ SIGNIFICANTLY different cooling rates on one side than the air exposed side ... can't imagine that being 'OK'.
I can't imagine the butyl (I think that is the sealant commonly used in hermitically sealed glazing) would easily be comromised at 600 degF I would think.
left the windows in a burned house...
they didn't take kindly to stresses and direct sunlight..
ended up replacing them...
once was enough...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
"Some days it's just not worth chewing through the restraints"
If the windows have a dark material in the spacer than its probably butyl. This melts at a low temperature, I've seen some that was melted by the sun. Contrary to popular beleif most windows are not vacuum sealed ,there is a desicant inside the spacer that absorbs the moisture inside the window after it is sealed with the butyl or other sealant. I wouldn't expect this seal to survive a fire.
Tom
It may depend on the material used for the spacers. Some of the non-metallic spacer systems tend to be very sensitve to higher temperatures, potentially resulting in debonding between the spacer and the glass. Other spacer systems (typically metallic) are better at withstanding temperature extremes and may not show any long term problems at all.
I would agree with Clewless that if the windows aren't broken then they may not have been subjected to really extreme temperatures during the fire. Glass can withstand very high temperatures as long as the heating is even - tempered glass for example is heated to over 1200 degrees during the tempering process without breaking, for example - but glass is also very sensitive to uneven heating, such as you would find in a fire. We have all likely seen examples of glass that has failed due to thermal stress even if not everyone would recognize it as such.
Glass is a lousy insulator, but it is also a very poor thermal conductor. It is quite possible for glass to fail in a window due to thermal stress simply because of an obstruction (telephone pole for example) throwing a shadow over a window that is otherwise in full sun. Undamaged and unflawed annealed window glass can break when internal stress levels exceed 2000 psi, and since one degree of temperature difference within a single lite is equivalent 50psi, a 40 degree difference between full sun and shadow (which is very possible) may result in glass failure.
All of which makes the concept of glass potentially "tempering" during a fire a very interesting idea and one that I have never heard addressed before reading this thread.
The eHow link describing how to "temper" glass is wrong. The directions that they give will not result in tempered glass. In order to properly temper glass, the core temperature has to exceed 900 degrees F, which could not happen in the eHow directions.
In order to temper glass, the exterior surface has to be very rapidly cooled. The time of heating, the soak time, and the cooling are all very controlled - to the point where there are different formulas or recipes for glass of different thicknesses - even a millimeter difference in glass thickness may require a different recipe. Even how the glass is loaded into the tempering furnace is carefully controlled in order to ensure proper tempering.
So can a fire temper the glass in windows? No, not in the classic sense of tempered glass. But could heat from a fire result in glass with residual thermal stress? Honestly, I don't know, but I suspect that it could in the right circumstances.
Again, a really interesting idea and I am going to follow up next week.
The danger is that the seals have been compromised. And, in the case of high efficiency windows, that the internal coatings have been damaged.
Clean a representative portion of a few windows and see if you can see any discoloration indicative of damaged coatings, etc. And also look around the edges for any obvious melting/damage to the seals between the panes. If you find neither then they may be worth a risk, but you may find the seals are damaged and they fog after 6-12 months.