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Post by Vortex on Feb 2, 2023 5:33:52 GMT -8
I tested that type of welding on 2 welds but the V wasn't grinded enough but it did work pretty well already! Will definitely do that for the door. In your case you already have the strength of your refractory board, my firebox bottom will be weak at every seam between firebricks I'm thinking the following layout, the layer of bricks, vermiculite board and then firebricks. So the vermiculite will get a bit stressed since it's not 1 board of refractory material on top of that. Since I don't have any experience with vermiculite board and the strength it has, I was thinking to place some metal frame underneath the vermiculite for more structural strength. (not sure if this would be overkill..) It's difficult for me to picture what you're describing. The Calcium Silicate board I used is weaker than vermiculite or ceramic fibre board, it's like blackboard chalk. The back and sides of my firebox are supported on the bricks underneath, but the V shaped floor is actually just sat on top of the CS board and the steel plate under that. |
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jonasp
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Post by jonasp on Feb 12, 2023 22:49:24 GMT -8
I'm not the best at explaining let me try again. First I have 2 layers of bricks then I welded a metal frame to put on top of the bricks followed by vermiculite board and then bottom of the firebox out of firebricks. Some more progress shots.  benches already tested by the dogs   |
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Post by Dan (Upstate NY, USA) on Feb 13, 2023 4:33:18 GMT -8
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Post by Vortex on Feb 13, 2023 11:44:20 GMT -8
I'm not the best at explaining let me try again. First I have 2 layers of bricks then I welded a metal frame to put on top of the bricks followed by vermiculite board and then bottom of the firebox out of firebricks. I'd redesign that so you don't need those firebricks under the V-shaped floor and make the ash-box deeper, with it that shallow you'll need to empty it almost every day to stop the ash pile from blocking up the bottom air supply. The brick across the middle will also stop the air flow and you'll get a big pile of unburnt embers in the middle that you will have to rake over the holes. A length of angle steel either end of the V-shaped floor sitting on top of the ash box side walls would do it. |
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jonasp
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Post by jonasp on Feb 13, 2023 23:07:54 GMT -8
I'm not the best at explaining let me try again. First I have 2 layers of bricks then I welded a metal frame to put on top of the bricks followed by vermiculite board and then bottom of the firebox out of firebricks. I'd redesign that so you don't need those firebricks under the V-shaped floor and make the ash-box deeper, with it that shallow you'll need to empty it almost every day to stop the ash pile from blocking up the bottom air supply. The brick across the middle will also stop the air flow and you'll get a big pile of unburnt embers in the middle that you will have to rake over the holes. A length of angle steel either end of the V-shaped floor sitting on top of the ash box side walls would do it. hmm a little bit hard to redesign that part it's quite stuck now.. you mean the additional air supply coming from the ashbox to burn the embers at the end of a fire? Wouldn't the angled steel deteriorate after a while? Thanks for your input I'll think about it before building further on the firebox |
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jonasp
Junior Member
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Post by jonasp on Feb 13, 2023 23:08:22 GMT -8
it's a new technology, cheap and fast |
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Post by Vortex on Feb 14, 2023 1:27:37 GMT -8
I'd redesign that so you don't need those firebricks under the V-shaped floor and make the ash-box deeper, with it that shallow you'll need to empty it almost every day to stop the ash pile from blocking up the bottom air supply. The brick across the middle will also stop the air flow and you'll get a big pile of unburnt embers in the middle that you will have to rake over the holes. A length of angle steel either end of the V-shaped floor sitting on top of the ash box side walls would do it. hmm a little bit hard to redesign that part it's quite stuck now.. you mean the additional air supply coming from the ashbox to burn the embers at the end of a fire? Wouldn't the angled steel deteriorate after a while? Thanks for your input I'll think about it before building further on the firebox That's the two things I would change on the bottom end of mine if I was building it now. The rear 3" of my V-shaped floor has support bricks under it, so I have a small 3" x 1/2" wedge of firebrick sat in the back of the ash-trap which holds the sides of the V-floor apart. Because of that I have to rake the embers forward every day or they dont burn up at the back there. You can see it in this picture: www.vftshop.com/images/others/Stove/V-floor.jpgThe other thing I would do different is make the ash-box deeper (presently 4" /100mm), as every few days I have to pull out the ash-box and move the pile of ash away from under the ash-trap, otherwise it starts to block the bottom air. Up to you if you do it or not but wanted to let you know now so you have the choice. |
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jonasp
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Post by jonasp on Feb 14, 2023 1:37:02 GMT -8
hmm a little bit hard to redesign that part it's quite stuck now.. you mean the additional air supply coming from the ashbox to burn the embers at the end of a fire? Wouldn't the angled steel deteriorate after a while? Thanks for your input I'll think about it before building further on the firebox That's the two things I would change on the bottom end of mine if I was building it now. The rear 3" of my V-shaped floor has support bricks under it, so I have a small 3" x 1/2" wedge of firebrick sat in the back of the ash-trap which holds the sides of the V-floor apart. Because of that I have to rake the embers forward every day or they dont burn up at the back there. You can see it in this picture: www.vftshop.com/images/others/Stove/V-floor.jpgThe other thing I would do different is make the ash-box deeper (presently 4" /100mm), as every few days I have to pull out the ash-box and move the pile of ash away from under the ash-trap, otherwise it starts to block the bottom air. Up to you if you do it or not but wanted to let you know now so you have the choice. I very much appreciate your input! I'll think about it and hopefully I'm able to find a solution. |
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jonasp
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Post by jonasp on Feb 15, 2023 1:01:10 GMT -8
I'm thinking about keeping the bottom as it is. The only place where a lot of embers can build up would be at the front I think. I've taken another picture to see the openings from top view. The ashtray frame i'll lower and extend it to be almost double height (10cm)  Is the angled metal frame in your picture for supporting the V shape or also as a stumble block for the primary air to flow over the bottom? |
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Post by Vortex on Feb 15, 2023 2:19:04 GMT -8
The V shaped floor on mine is supported at the front and back on the top of the ash-box walls below. The front only has a 2" overhang, and there's always a little air leaking in from the primary air so embers at the front aren't an issue there. It's the rear where there is a 3" overhang of the brick underneath and no other source of air, so hopefully yours will be OK. It's easier to push embers back than pull them forward anyway. The piece of steel at the front is the threshold. That picture was from when I was experimenting with it at different heights, but it's the best shot I have that shows the little 3" slope in the back end of my V floor where the support bricks are underneath.
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jonasp
Junior Member
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Post by jonasp on Feb 15, 2023 23:25:01 GMT -8
The V shaped floor on mine is supported at the front and back on the top of the ash-box walls below. The front only has a 2" overhang, and there's always a little air leaking in from the primary air so embers at the front aren't an issue there. It's the rear where there is a 3" overhang of the brick underneath and no other source of air, so hopefully yours will be OK. It's easier to push embers back than pull them forward anyway. The piece of steel at the front is the threshold. That picture was from when I was experimenting with it at different heights, but it's the best shot I have that shows the little 3" slope in the back end of my V floor where the support bricks are underneath. have you considered making a small sloped firebrick to fill the backspace so the embers would roll forward? |
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Post by Vortex on Feb 16, 2023 1:52:49 GMT -8
Yes that's what's been there since I made it, but it doesn't help the air get to the embers in the back corner above it, so I have to rake them forward every day - not a big problem just one of those little niggles that I would do different next time.
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jonasp
Junior Member
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Post by jonasp on Feb 16, 2023 1:57:23 GMT -8
Yes that's what's been there since I made it, but it doesn't help the air get to the embers in the back corner above it, so I have to rake them forward every day - not a big problem just one of those little niggles that I would do different next time. ah i could've guessed you already thought about that hehe |
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jonasp
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Post by jonasp on Feb 19, 2023 1:37:27 GMT -8
I'm building the afterburner today but i have a question regarding forcing the gas stream around the white oven. The exit of the top chamber would be to the right side. (9.7cm height x 24,7 wide) The gas stream would go up over the white oven, down until it reaches the bottom of the oven then it'll enter the full bell. My question is regarding the insulated bottom i would create after the exit is that necessary? I think the small bench will be much harder to warm up since the gap between firebox and wall to go to the small bench is only 10cm. I hope i made myself understandable hehe, hopefully the picture will help (i lowered the bell wall so you can see it)  |
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Post by Vortex on Feb 19, 2023 3:02:05 GMT -8
Probably a good idea to insulate the bottom there after the exit. If you use CF blanket you could always remove it through the cleanout If necessary.
Is there a reason your afterburner top chamber exit is a bit less than 1 csa?
(97 x 247 = 23959 90 x 90 x 3.142 = 25450 23959 / 25450 = 0.94% csa)
Having it long and thin and that far forward tends to make it pull more on one side of the vortex. A squarer exit near the back works better, that's why I have that recessed area in the rear of the top chamber so I can make the exit farther back equalling the pull and maintaining the important surface area to volume ratio of the top chamber.
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