Source for Small Woodstove Sight Glass

[nedsim]

I'd like to add a control for secondary combustion air to the door of my stove, but some visual feedback on the effect of the added air seems important. The stove is very similar in design to the old Jotul 602's with the big round vent and no glass, but welded steel rather than cast iron. So I'm looking for a piece of the appropriate glass, ideally about 2 inches in diameter, give or take, to put in the door above the existing vent. I'm hoping someone can point to a production stove that might have a replacement part available, or a source of custom cut glass at a reasonable price. I've found places that will cut pyroceram to order, but the prices seem exorbitant for such a small piece -- in the range of $100 each.

The stove is one I built about 40 years ago. I had a welding business making primarily stainless yacht hardware, but when things got slow I'd make a batch of stoves for sale. Don't remember how many I built, but they ranged in size from a 12" stick (which my daughter now has in the far end of her 1830's farmhouse) up to 3 monsters that went into boat shops that swallowed 48" sticks. The most popular were 24". The one we're using is 16", so very close to the Jotul with perhaps 30% more internal volume.

I should probably be looking for a more modern stove, but this one heats our house on 2-1/2 cord per year, so the ROI of a more efficient stove is not attractive. Not to mention, I'm attached to this one.

 

[WES999]

I did something similar to my old Fisher stove some time ago.
I think this is what I used https://www.mcmaster.com/84815K45/
4" X 4" .197 $20

 

[nedsim]

Thanks for the reply.

McMaster used to carry round discs of high temp glass (Vycor), but no more. Around 1971 a 2" dia x 1/4 disc was $9.72, by the early 90's the price was $40. Unfortunately a round piece will be much easier for me to work with, though I guess I should actually come up with a design before I insist on that.

I stopped into a stove shop today and the seemingly knowledgeable owner was not aware of any replacement glass that fit the bill. He did direct me to a local glass place that's made replacement glass not available from the OEM. I've not checked with them yet.

While looking for info on what it takes to cut Pyroceram (wondering how hard it'd be to make a square piece into an octagon) I came across another place where a custom cut 2" disc is $42. Guess it's time to come up with a real design.

How did the modification to your stove work out?

 

[sean donato]

Just gonna toss this out there, I'd be going with a square glass vs round/oval. It should be about half the cost. I'd also check with local glass shops. There's one in town that cut the glass for my old man's stove as we waited. I'd like to think most glass shops would/could do the same.

 

[nedsim]

Just gonna toss this out there, I'd be going with a square glass vs round/oval. It should be about half the cost. I'd also check with local glass shops. There's one in town that cut the glass for my old man's stove as we waited. I'd like to think most glass shops would/could do the same.

I also figured straight cuts would be cheaper, but it's not so, at least with the online places that auto-quote custom sizes. Which, along with the fact they'll cut notches and holes that would be difficult or impossible by conventional means, leads me to believe they're cutting with abrasive waterjet. I expect the local glass places that cut the old fashioned way will charge much more for curved cuts. I need to check with them before settling on a plan. Or buy a new stove, which opens up a whole new box of pros and cons.