Tongue and Groove Door Seals.

[wkpoor]

Seems to me door seal is quite a frequented topic on this forum. Lately I've been paying more attention to different mfg doors when I visit stove shops. Very few do the tongue and groove system and fewer yet do it with radius-ed corners. A T&G system allows a good tight seal with a small 1/4" rope. And the groove shields the rope from the fire with the door open or closed. And the tongue can help stiffen the frame. All in all it seems to be the best door seal system. So why don't more mfgs use it?
BTW yes the Elm uses a T&G door seal and so far I've had no troubles with it or the door and I routinely fire my stove over 800deegres. And before you jump all over me for firing a stove that hot the Mfg says it is perfectly ok to do that. I wouldn't do that if it weren't in a basement setting though.

 

[Highbeam]

I'll tell you why they don't use it. When the hinges wear and the door sags, that tongue and groove doesn't align right and then you have problems closing the door as well as sealing it. So before a manufacturer can use T&G they need to figure out a good hinge system as well as an accurate assembly system.

Hearthstone uses a T&G design on their doors which work very well when everything is new.

 

[wkpoor]

Thats good and I had not thought of that. The Elm doesn't do anything special in that regard. When you close the door it self aligns to the groove.
Seems a simple field replaceable bushing would take care of the wear issue.

 

[jimbom]

T & G might be more common than you think. My Atlanta stove has a door gasket that is completely recessed in a groove. However, this stove has big hinge pins for the weight and size of the door. And the tongue is smaller than the grove, so perhaps this is not what you were discussing.

 

[wkpoor]

T & G might be more common than you think. My Atlanta stove has a door gasket that is completely recessed in a groove. However, this stove has big hinge pins for the weight and size of the door. And the tongue is smaller than the grove, so perhaps this is not what you were discussing.

Sounds like it is. Has it been a trouble free design?

 

[BrotherBart]

They are called "knife edge" door frames. PE uses them and if you will notice a lot of the cracks folks have had have been in the corners of the things. With knife edge they can't radius the door frame cutout.

And those things are brutal on door gaskets. Had'em before. Don't want'em again.

 

[jimbom]

T & G might be more common than you think. My Atlanta stove has a door gasket that is completely recessed in a groove. However, this stove has big hinge pins for the weight and size of the door. And the tongue is smaller than the grove, so perhaps this is not what you were discussing.

Sounds like it is. Has it been a trouble free design?

Yes. The stove is ~20+ years old and doesn't show much use. We bought it second hand. It is installed in our basement. I ran it for one month when it was first installed to make sure all parts of the stove and install were safe. Every fall and occasionally through the winter I run a load of wood to keep things ready to go. It burns very well. I could very easily see using it all the time except the thing is ugly as a toad and the wife has banned it from the civilized part of the house.

The size and close tolerances of the hinges, coupled with the size and weight of the door indicate this gasket system will last indefinitely.(Heavy hinges/light door.) There will be no alignment problems unless the steel stove box melts. The door is high quality cast iron with careful machining and tolerances. The gasket is in excellent condition.