Glass* (IR?) coating

[Brian VT]

I read that the glass* is installed with the coating on the outside.
I can't find any markings on my glass*. How can I tell which side the coating is on ?

glass* = transparent ceramic, don’t use plain or tempered glass in a wood stove.

 

[Corey]

Hummm...I'd never heard of such a thing until now, but sure enough...searching a bit I found a harman manual which states:

Note: this glass has a special IR coating on one side. This coating must be to the outside of the stove. The coated side has a label on it. Do not remove the label before installing the glass. If label is missing, check for continuity.

So now the question is what do they mean by continuity? The first thing that comes to mind would be electrical continuity. IR coatings are usually some type of metal film so if you have any type of little multimeter, you could set that to measure resistance and put the probes fairly close together first on one side of the glass, then on the other. If you found one side has lower resistance, this is due to the metal film and would be the IR side. You might be able to amplify the effect by cutting some small pieces of aluminum foil, pressing them against the glass (for better contact with the coating) then putting the multimeter probes on them.

Beyond that - can you see any difference if you hold the glass up to a light and look at a very shallow angle across the surface? You may see one side has a bit of a tint that the other does not.

 

[Jerry_NJ]

Good thinking "cozy". Now I wonder if I was cheated when I bought a Quadrafire, or maybe not, I'll have to look to see if it has an IR coating, I don't know.
Then too, why would one want an IR coating?

 

[Hogwildz]

Damnit, now ya have me wondering.
The glass I got from onedayglass, didn't say anything bout a special side, no label, no nutting.
Seems to be working fine, so I ain't going to worry bout it.

 

[Brian VT]

IR coatings are usually some type of metal film so if you have any type of little multimeter...

Brilliant ! I have one of those meters and have never used it. I'll give it a shot.

 

[Brian VT]

It worked ! LOL !
There is a continuity setting on my meter, which is what I used.
And...I have the glass in correct. Thanks.

 

[Hogwildz]

Did you check both sides just for the hell of it?

 

[Brian VT]

Yup. One side showed nothing (open circuit) and the other brought up some numbers. I don't know what those numbers mean (resistance?) but it told me all I needed to know.

 

[Corey]

Well, there ya go...glad to hear it worked! You were probably looking at resistance in ohms. Plain glass or transparent ceramic stove glass* is an insulator - so you saw 'open circuit' or 'infinite' ohms resistance. On the IR side, it conducts slightly so you saw something less...maybe mega ohms, or kilo ohms of resistance, but it would still have some 'conductivity' versus the glass* which has none.

For the IR coating being on the outside, I think they are trying to protect it from the fire and cleaning products applied to the inside of the glass*, plus I can only guess they are trying to reflect more heat back into the stove - help out the secondary burn and help keep the glass* clean as well.

Hog- I doubt off-the-shelf replacement glass* would have the coating unless you specially ask for it or search for a supplier. Probably not required to have it, but the glass* might stay a little cleaner with it.

glass* = transparent ceramic, don't use plain or tempered glass in a wood stove.

 

[Prada]

We bought an extra glass for our Buck (just in case anything ever happens) and I have NEVER heard of any of this till now. I just read all this info to Hubby and he is rather shocked too. Thanks so much for this information.

 

[downeast]

Well, there ya go...glad to hear it worked! You were probably looking at resistance in ohms. Plain glass or transparent ceramic stove glass is an insulator - so you saw 'open circuit' or 'infinite' ohms resistance. On the IR side, it conducts slightly so you saw something less...maybe mega ohms, or kilo ohms of resistance, but it would still have some 'conductivity' versus the glass which has none.
For the IR coating being on the outside, I think they are trying to protect it from the fire and cleaning products applied to the inside of the glass, plus I can only guess they are trying to reflect more heat back into the stove - help out the secondary burn and help keep the glass clean as well.
Hog- I doubt off-the-shelf replacement glass would have the coating unless you specially ask for it or search for a supplier. Probably not required to have it, but the glass might stay a little cleaner with it.

Unless the replacement is clear ceramic ( re: space shuttle heat shield ), it should never be used in a wood stove. It is not GLASS.
Never use any kind of glass replacement for a stove.

 

[Corey]

Ya Ya - This topic comes up so much around here, I kind of took for granted that folks would know we were talking about the ceramic, but i'll edit the last post for clarity just in case.

 

[Brian VT]

Me too. You can't be too careful with so many lawyers out there ready to have their house repoed because they overbought. LOL !

 

[downeast]

Ya Ya - This topic comes up so much around here, I kind of took for granted that folks would know we were talking about the ceramic, but i'll edit the last post for clarity just in case.

Assumptions are just that. Since most here are of the self assumed ( "there you go again Mr Gorbachev" ) high tech and experienced status %-P , you have an obligation for clarity towards some that may not have the expert experience you assume for yourselves. Drop down mentally into the mind of someone who only recently bought a stove, has no idea about the process of wood or pellet burning, and asks serious questions that deal with safety and efficiency and process. When you say "glass" or "glass replacement" they may think that literally. Not bright move by the engineers and software gurus .

Now really, what are your backgrounds and experience heating with wood ? A year or so ? "Up from" the 60 degree F furnace to room temperature ? Entertainment fires on weekends ? Curious minds want to know. :roll:

 

[Corey]

Well, since the issue is resolved - I guess we're OK to hijack this thread...

Wood burning experience? Well...'casual' burning from ~ 1987 - 1990 when my folks bought a house with a fireplace. Took a few years off to go to school, then started burning for 90+% of my heat when I got my own place 1995 - 1998. Took another break when I rented a place with no wood heat from 1998 - 2001. Then started back on the 90+% heat plan when I bought my current house in 2001. The very first upgrade was a fireplace insert!

Am I qualified?

 

[firefighterjake]

Well, there ya go...glad to hear it worked! You were probably looking at resistance in ohms. Plain glass or transparent ceramic stove glass is an insulator - so you saw 'open circuit' or 'infinite' ohms resistance. On the IR side, it conducts slightly so you saw something less...maybe mega ohms, or kilo ohms of resistance, but it would still have some 'conductivity' versus the glass which has none.
For the IR coating being on the outside, I think they are trying to protect it from the fire and cleaning products applied to the inside of the glass, plus I can only guess they are trying to reflect more heat back into the stove - help out the secondary burn and help keep the glass clean as well.
Hog- I doubt off-the-shelf replacement glass would have the coating unless you specially ask for it or search for a supplier. Probably not required to have it, but the glass might stay a little cleaner with it.

Unless the replacement is clear ceramic ( re: space shuttle heat shield ), it should never be used in a wood stove. It is not GLASS.
Never use any kind of glass replacement for a stove.

Sure, now you tell me after having the local True Value Hardware Store cut me a piece of glass for my stove from that old storm window I had kicking around.


And yes . . . I am kidding.

 

[Corey]

Ahhh, Jake...funny you should mention cutting up an old storm window for glass. About this time last year, I was trying to be frugal and salvage a piece of glass from an old storm window for another project. I got everything lined up and ran the glass cutter across the pane, then I grabbed the edge of the glass and gave it a quick 'snap' down against the edge of the table (like I've seen the pro's do multiple time). At that second..."BOOM" the entire 3' x 4' piece of glass shattered into thousands of tiny bits. I instantly knew this was a pane of tempered glass!

Still not ceramic for stove duty, but I was surprised that the old window had tempered glass instead of the regular old glass.