Win a copy of 5 Acres & a Dream this week in the Homestead forum!
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education skip experiences global resources the cider press projects digital market permies.com private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Nicole Alderman
  • Anne Miller
  • Pearl Sutton
  • r ranson
  • Mike Haasl
  • James Freyr
stewards:
  • paul wheaton
  • Joylynn Hardesty
  • Burra Maluca
garden masters:
  • Steve Thorn
  • Greg Martin
gardeners:
  • Kate Downham
  • Jay Angler
  • thomas rubino

!!!!!!!!!! Glass top range teardown

 
gardener
Posts: 676
Location: Penticton, Canada
158
building solar woodworking rocket stoves wood heat greening the desert
  • Likes 3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I have been wanting to replace that old perlite/clay heat riser I've been using up until now which is getting me by, but it time for an upgrade. Looking through the classifieds, I found 2 free glass top ranges. Monday, I plan on picking them both up in hopes that they will provide me with enough ceramic fiber blanket to build a 5 minute riser and perhaps enough to replace some of the thicker rock wool around the combustion chamber too. I'll save the glass too in case one day I want to make a double shoebox rocket cooktop and/or cut it up and make a door or viewing window. We'll see how it goes!
 
Gerry Parent
gardener
Posts: 676
Location: Penticton, Canada
158
building solar woodworking rocket stoves wood heat greening the desert
  • Likes 4
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Turned out one was unavailable but I did get the other one. Its kind of a nice unit and am looking to see if it can be repaired before tearing it apart.
As the name says on the top glass its "Schott" which is the real deal for high heat ceramic glass. Hopefully the ceramic fibre is on the inside too.
Looked up the price of a new glass top.... $475 ! Yikes.
Electric-Range.JPG
[Thumbnail for Electric-Range.JPG]
Schott-glass-top.JPG
[Thumbnail for Schott-glass-top.JPG]
 
Gerry Parent
gardener
Posts: 676
Location: Penticton, Canada
158
building solar woodworking rocket stoves wood heat greening the desert
  • Likes 3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
The cook of the house did not want the range so I went ahead and started to tear it down. I haven't seen anywhere of this being documented so I thought I'd post a few pictures of what it looks like. Of course, all ranges are going to be slightly different but the general idea I think should be the same.

I removed as many screws as I could see until the top glass frame of the range was free to move up and down on its hinge (to change the elements if needed). With a utility knife, I cut all around the perimeter of the glass: Its some sort of silicone I think.
This did not free it entirely as on all four corners (from underneath) it is also secured with some kind of adhesive that needs to be cut also. It then popped right off.
The third photo shows what it looks like with lights shining through it: very opaque. The bottom of the glass has little dimples in it and is very brownish in colour which makes the visual look very dark and distorted.
To be continued.....
1.cut-silicone-seal-all-around-perimeter.JPG
[Thumbnail for 1.cut-silicone-seal-all-around-perimeter.JPG]
2.-cut-4-corners-held-with-double-sided-tape.JPG
[Thumbnail for 2.-cut-4-corners-held-with-double-sided-tape.JPG]
3.-Regular-light-bulbs-as-seen-through-top-glass-pane.JPG
[Thumbnail for 3.-Regular-light-bulbs-as-seen-through-top-glass-pane.JPG]
 
Gerry Parent
gardener
Posts: 676
Location: Penticton, Canada
158
building solar woodworking rocket stoves wood heat greening the desert
  • Likes 4
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
The teardown continues as the metal skin is removed. There was a combination of screws and tabs holding it together. Most cables were unplugged to access the back insulation. Not sure why there were different thicknesses of insulation - It wasn't that some were matted more that others.
The insulation was almost identical looking to the batt fiberglass insulation you use to insulate a house. Didn't experience any more itching or loose fibres to breathe in like the fiberglass stuff.
There were also what looked to be compressed vermiculite disks (with little fibres) under and around the heating elements. I didn't see any immediate use for them but could have potential if they were needed.
One really nice perk of the new riser is the diameter size reduction (to provide more room for gasses to flow more easily around the riser and down to the manifold) and the weight was considerably less. I could easily lift it with one hand! My perlite/clay riser I have to grunt with both hands to lift it.
The height difference between the two risers was only because I used a strip of sheet metal for the outer shell to hold the insulation that was 24" wide. No big deal as the heat riser for a batch box I'm told can be shorter. Besides, it is an experiment anyway!
On to the photos....
1.-Top-and-side-insulation-is-about-2-thick-.JPG
[Thumbnail for 1.-Top-and-side-insulation-is-about-2-thick-.JPG]
2.-Back-insualtion-is-about-2.5-thick.-Bottom-was-about-3-.JPG
[Thumbnail for 2.-Back-insualtion-is-about-2.5-thick.-Bottom-was-about-3-.JPG]
3.-Disks-around-top-burner-elements.-No-use-for-them-though.JPG
[Thumbnail for 3.-Disks-around-top-burner-elements.-No-use-for-them-though.JPG]
4.-Fiber-blanket-vs-perlite-and-clay-riser-comparison.JPG
[Thumbnail for 4.-Fiber-blanket-vs-perlite-and-clay-riser-comparison.JPG]
5.-Fiber-blanket-installed-and-ready-for-action.JPG
[Thumbnail for 5.-Fiber-blanket-installed-and-ready-for-action.JPG]
 
gardener
Posts: 2745
Location: latitude 47 N.W. montana zone 6A
487
cat pig rocket stoves
  • Likes 3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Sweet Deal Gerry !  
Your gona love that new riser!
Awaiting your post on how well it does!
5a916-dragon_of_flames_by_elegantartist21-d4pya6u.jpg
[Thumbnail for 5a916-dragon_of_flames_by_elegantartist21-d4pya6u.jpg]
 
gardener
Posts: 2645
Location: Cincinnati, Ohio,Price Hill 45205
213
forest garden trees urban
  • Likes 3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Thanks for doing this and sharing it as well.
I didn't realize that these units used ceramic fiber insulation,  so cool!
It seem like one item could provide insulation, a top for  your bell(the glass)  and an oven, complete with a working, well fit door.
 
Gerry Parent
gardener
Posts: 676
Location: Penticton, Canada
158
building solar woodworking rocket stoves wood heat greening the desert
  • Likes 4
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Well gents, its been an interesting experiment but just found a glitch in the matrix.... read on.  

This afternoon I fired up the beast and put a full load of wood in. Everything ran quite smooth without a hitch. A few hours later (with welding gloves on because I was impatient... I mean eager) I removed the barrel to inspect the heat riser. The outside skin was fairly clean and the top of the insulation was well intact. Then when I looked down the 'barrel' of the heat riser I was quite surprised. The 6" opening near the bottom had shrunk to about half that size and it looked like a marshmallow roasted over a fire. I took it off, laid it on its side and inspected the bottom. The pictures below say it all.

Long story short, I don't think this is ceramic fiber blanket, superwool or whatever else you would like to call it. It may be a high heat insulation suitable for oven temperatures but certainly not what will work for the extreme temperatures of a heat riser. Sigh!  😢

My original inspiration came from this thread: ceramic-fiber-build-discussion over at proboards mentioned by Matt Walker (the 6th post) then again on the last post on page 1.
I don't know if there was something I missed or perhaps every manufacturer uses a different insulation product, but whatever the deal, it wasn't meant to be this time around.
I think I will drop Matt an email and see if he could clarify things a bit.
All in all though, it was an experiment and this small setback certainly won't curb my rocket science explorations.

EDIT:  Well there's still the glass top to play with!
EDIT2: I just watched Matts video posted from the link above and in it he says at 28:50 that he's using the salvaged insulation from the range to cover the outside of the metal of the heat exchanger which of course would not be as hot as the inside of a heat riser. I could see it working there or perhaps even on the outside of a brick core as insulation.
1.-Heat-riser-after-first-burn.JPG
[Thumbnail for 1.-Heat-riser-after-first-burn.JPG]
2.-Looking-down-heat-riser-after-first-burn.JPG
[Thumbnail for 2.-Looking-down-heat-riser-after-first-burn.JPG]
3.-Bottom-of-heat-riser.JPG
[Thumbnail for 3.-Bottom-of-heat-riser.JPG]
 
thomas rubino
gardener
Posts: 2745
Location: latitude 47 N.W. montana zone 6A
487
cat pig rocket stoves
  • Likes 4
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Oh Man! Dang , hate it when that happens!
At least the old reliable riser was there to step up and keep getting the job done!
Might take longer than five minutes, but i'm sure you have a 5 minute riser in your future.
 
William Bronson
gardener
Posts: 2645
Location: Cincinnati, Ohio,Price Hill 45205
213
forest garden trees urban
  • Likes 4
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Great test Gerry !
Thanks for sharing this experience.
 
William Bronson
gardener
Posts: 2645
Location: Cincinnati, Ohio,Price Hill 45205
213
forest garden trees urban
  • Likes 3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Just now added to my to do list is a massive batch box with everything as transparent as possible.
I think we could do the burn chamber,  door,  and bell at a minimum.
I have a local metal recycled that might be the place to intercepting glass top ranges.


I imagine building this rocket glass heater it in the center of a large gathering place.
It wouldn't  be very efficient, being rather low mass, but it would compare favorably to a bonfire, offering lots of radiant heat and warm light  without the smoke.

In a steam room or sweat lodge, the glass could be a great surface to flick water at/throw herbs on.

Imagine an windowless insulated  grow house,  warmed and illuminated by a  rocket glass heater and biogas lanterns.

The lack of mass is kind of a limitation, so perhaps this would be the place to choose water as thermal mass.
Normal silicon caulk is rated for way higher than 212°,  so the techniques used by DIY aquarium builders should work to build a boiling vessel.
 
gardener
Posts: 1741
Location: Pacific Wet Coast
581
duck books chicken cooking food preservation ungarbage
  • Likes 5
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Gerry Parent wrote:

Long story short, I don't think this is ceramic fiber blanket, superwool or whatever else you would like to call it. It may be a high heat insulation suitable for oven temperatures but certainly not what will work for the extreme temperatures of a heat riser. Sigh!  

This is such a good reminder of just how hot parts of a rocket stove can get and how important it is to inspect things carefully, and design things so they *can* be inspected carefully, particularly when you're experimenting! I've been gradually collecting the things I'll need to do an outdoor one for learning on, but I'm totally cool with learning from other's mistakes! Thanks for the great pictures, Gerry.
 
Gerry Parent
gardener
Posts: 676
Location: Penticton, Canada
158
building solar woodworking rocket stoves wood heat greening the desert
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I heard back from Matt Walker. This is what he said in regards to the insulation:

"Hi Gerry,

 It looks like your stove manufacturer used a lower grade insulation. I'm not surprised that there are variations on the construction across different models, but it's the first I've heard of it.

You can find superwool online at Amazon for reasonable pricing. If you are unsure or not willing to experiment then that's likely a better source for you.

Warmly,

 Matt"



I then asked if it was OK to share his response and this is what he said:

"Hi Gerry,

 Sure, you are welcome to share my thoughts, thank you for asking. Thanks for your continued support as well, I greatly appreciate you and the gang over there and all the support over the years. Let me know if there's more I can do to help.

Warmly,

 Matt"


So the facts are:  1) Not all salvaged glass top ovens are the same so my findings may not reflect what you find

2. Matt is a super awesome guy!
 
pollinator
Posts: 239
21
  • Likes 5
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I wonder if that also applies to the actual glass, obviously all glass hob tops can withstand hight heat but perhaps some are better quality than others?
I have had one for a few months but not actually fitted it yet......
 
Gerry Parent
gardener
Posts: 676
Location: Penticton, Canada
158
building solar woodworking rocket stoves wood heat greening the desert
  • Likes 5
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

Fox James wrote:I wonder if that also applies to the actual glass, obviously all glass hob tops can withstand hight heat but perhaps some are better quality than others?
I have had one for a few months but not actually fitted it yet......


Don't know the answer to that one yet Fox. Perhaps this summer I'll make something with it and post my results.
I'm wondering about the door glass too. There are 2 layers and don't know if the inside one is more heat tolerant than the outside one, the same or both not good enough for the high heat of a RMH.
I think though I'd like to test cut the door glass with my wet tile saw to get some practice before hacking into the top piece. Its nice to have a free piece to do this with as I think I'd be a lot more nervous if I spent a lot of money and have it crack on me.
 
Fox James
pollinator
Posts: 239
21
  • Likes 4
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I have been through a few pieces of glass, I get free off cuts from a local stove company, some last longer than others .
The glass is directly above my heat riser, I have only had one piece that actually cracked but most go opaque after around 10 hours or so.
I was given a hob top that I will try out soon, it is almost new without any scratches or obvious wear, my stove can show temperatures over 600c so it will be a good test!
 
Gerry Parent
gardener
Posts: 676
Location: Penticton, Canada
158
building solar woodworking rocket stoves wood heat greening the desert
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Thanks for the tip on the off-cuts Fox. I think I read about the colour change over at Proboards. Should look that up again.
The glass top I salvaged from the range is so opaque that I don't know how much of the flame will be seen as in the DSR in allerton abbey: double-shoebox-rocket-cooktop or if it will get even more dark. Time will tell.

In the meantime, I just had an idea that since my batch box is still not cobbed in around the burn chamber, I could experiment with that door glass and make something that resembles Peters batch box thingy with the glass acting as the roof. I know it may not survive that kind of heat nor is it good to reduce the insulation and lower combustion temperatures but hey... lets see what happens!
Would I need to put a rope gasket down first then just loosely set the glass in place so that it has room to expand/contract without cracking? Any thoughts?
 
Posts: 24
3
  • Likes 3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hey Gerry,
Not a frequent poster here, but hopefully you can see past that. Please don’t cut that glass top! Often times tempered glass will shatter when being cut, but if it doesn’t using it in high heat could be seriously dangerous. The reason being: tempering glass adds a huge amount of surface stress all around the entire piece. This results in super strength properties compared to annealed glass, and the “safety feature” of catastrophically shattering into small bits (not shards) when broken. Cutting it unbalances that stress.

If you give it a try anyway, be prepared both while cutting or subjecting to heat for the piece to instantly shatter into 1/4” cubes.

Kind regards,
Mark
 
Fox James
pollinator
Posts: 239
21
  • Likes 3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi Mark, do you think that only applies to ceramic cooker tops because the normal ceramic hight temperature glass can be cut quite easily with a standard hand held glass cutter.
I have never tried cutting a cooker top but, I have cut plenty of ceramic glass.
 
Gerry Parent
gardener
Posts: 676
Location: Penticton, Canada
158
building solar woodworking rocket stoves wood heat greening the desert
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Thank you for the warning Mark. I am only going on what a few others have said from their experiences with cutting this kind of glass. I do plan on taking extra precaution just to be on the safe side though. Probably be a few more days before I have the opportunity to get to it though. Will be sure to keep you all updated on my success or failure.
 
gardener
Posts: 687
Location: +52° 1' 47.40", +4° 22' 57.80"
96
woodworking rocket stoves wood heat
  • Likes 5
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
The kind of glass that says "Schott" and "Ceran" in one of the upper corners is glass ceramic, certainly not tempered glass. I have cut one at Paul Wheaton's in 2017, in fact it is the one of the rocket cook top in Allerton Abbey. And I did some small clear pieces at home, also using a tile wet saw. Very important: support the glass with a piece of plywood or the like and cut it in two or three passes. I never tried to cut it with an ordinairy glass cutter, by the way.
 
Gerry Parent
gardener
Posts: 676
Location: Penticton, Canada
158
building solar woodworking rocket stoves wood heat greening the desert
  • Likes 3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Thank you for the tip and support Peter, both you and from the plywood  :)
 
Fox James
pollinator
Posts: 239
21
  • Likes 6
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I have watched a very experienced elderly gentleman cut replacement new glass to fit the individual windows in wood burning stoves.
He simply places the 300mm square panes of hight temperature glass over the selected replacement frame and cuts it free hand with a glass cutter.
I go to this fireplace company to collect whatever might be on interest to me from their rubbish skip, I usually get a few bits of glass left over from the 300mm panes, they have hundreds of the squares staked in the workshop.
I cut the piece in the picture with my cutter and even managed to round over the edges with a wet diamond stone.
CB699B62-23C5-424E-91DC-4702B2129C5B.jpeg
[Thumbnail for CB699B62-23C5-424E-91DC-4702B2129C5B.jpeg]
 
Mark Boucher
Posts: 24
3
  • Likes 6
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
My warning is based on knowledge of tempered glass in general and a single experience of an employee walking across a glass top range during a cabinet install. It shattered like tempered glass, but I have no info about how that particular glass was labeled.

Looks like “ceran” is not tempered, so...

Sorry for raising the warning unnecessarily!
 
Gerry Parent
gardener
Posts: 676
Location: Penticton, Canada
158
building solar woodworking rocket stoves wood heat greening the desert
  • Likes 3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Mark,  No worries mate! We are all here to learn and even to expand on what we think we know.
 
pollinator
Posts: 1146
Location: Virginia USDA 7a/b
256
hugelkultur forest garden hunting chicken food preservation bee
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Excellent thread everyone. This is super interesting. following but wanted everyone to know this isnt just an echo chamber.
 
It runs on an internal combustion engine. This ad does not:
Permaculture Technology Jamboree: June 29th-July 10th, 2020, Wheaton Labs
https://permies.com/wiki/permaculture-tech-2020
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!