|
Post by pinhead on Oct 20, 2014 10:06:48 GMT -8
The better-insulated (lighter) the heat riser, the better.
Metal (even stainless) absolutely, unequivocally, unquestionably will burn out when used in a heat riser. There is absolutely no getting around it. You may get a month out of it if you fire it a couple times a day.
Light/insulative firebrick is the way to go.
Or make a more exotic riser out of perlite/waterglass as discussed in a few threads on the forum.
I'm going to try the perlite/waterglass since I don't have access to any "local" insulative firebrick.
|
|
JJ
Junior Member
Posts: 56
|
Post by JJ on Oct 20, 2014 12:40:07 GMT -8
Stove pipe will burn out, so you gotta do the clay/perlite thing (or clay/vermiculite). There are some folks here that will very firmly insist that the lighter heat risers are THE WAY.. They have a VERY good point. Your heat retention should really be in the mass (bench, bell, etc.) and lighter heat risers make for faster starting stoves that burn clean earlier. I'm a little more old-school than that.. I'm of the opinion that if it works (well), it's good. No broken, no fix. My heat riser (on this one) is anything but light. It's 9x4x2.5 3000 degree rated fire brick insulated with a layer of clay/sand cob. I used hardware cloth to wrap it and keep it circular. I did a small test burn today - without the barrel (I like to do test runs as I go throughout the entire process...call me crazy or whatever) and it's about 32 degrees in the house currently. Yes - I'm cold blooded, grew up in South Dakota and a tight wad to boot so I don't wanna use my salamander's propane too early yet. The test burn I did, I just used tissue and it only took me 1 warm up with tissue before the second wad of tissue took off like a beauty (see video below in a few - it's uploading atm to youtube). The woman who raked me over the coals is 70'ish and was just hell bent on me using stove pipe instead of fire brick. She didn't say anything about cleaner or faster burn...but she did say that I just put a whole lot of extra work on myself using fire brick and "scolded" me lol. I didn't see anymore work out of it to be honest..I love building these and I generally just put put when I build them - I don't like to rush. I appreciate the info K. I guess I'm kinda like you - if it works it works and although I see a lot of "math" going on here - I have never used math...I just kinda go on my gut and ears - sometimes smell. Instinct ya know? Probably not orthodox to most rmhers...but ah well. Good info to know for future use. Thanks ^^
|
|
JJ
Junior Member
Posts: 56
|
Post by JJ on Oct 20, 2014 12:43:56 GMT -8
The better-insulated (lighter) the heat riser, the better. Metal (even stainless) absolutely, unequivocally, unquestionably will burn out when used in a heat riser. There is absolutely no getting around it. You may get a month out of it if you fire it a couple times a day. Light/insulative firebrick is the way to go. Or make a more exotic riser out of perlite/waterglass as discussed in a few threads on the forum. I'm going to try the perlite/waterglass since I don't have access to any "local" insulative firebrick. Waterglass. Never heard of it. Now you're getting my search fu all fired up. I'll have to look at some of the threads...I've been so out of the loop for a few years...I really need to kick myself in the arse and giddyup and get caught up. You'll have to definitely share pics and conclusions when you do this. What part of the world are you from? I have a keen sense of smell for fire brick Perhaps I could help you find some.
|
|
JJ
Junior Member
Posts: 56
|
Post by JJ on Oct 20, 2014 12:57:59 GMT -8
Here's the video:
|
|
|
Post by pinhead on Oct 20, 2014 13:02:35 GMT -8
Waterglass. Never heard of it. Now you're getting my search fu all fired up. I'll have to look at some of the threads...I've been so out of the loop for a few years...I really need to kick myself in the arse and giddyup and get caught up. You'll have to definitely share pics and conclusions when you do this. What part of the world are you from? I have a keen sense of smell for fire brick Perhaps I could help you find some. I'm in central KS. I have a lot of dense red fireplace brick, though I haven't been able to find any local insulating firebrick. I recently "discovered" waterglass (sodium silicate) by reading through this thread: Fireclay and Perlite, add Fire Barrier or Furnace Cement?If you'd like to make some waterglass, check out this webpage: Make Sodium Silicate. I'll be using "Mimi Litter" brand kitty litter, water, and Sodium Hydroxide.
|
|
JJ
Junior Member
Posts: 56
|
Post by JJ on Oct 20, 2014 13:10:04 GMT -8
I do have a question though - I've never insulated using that outer layer of cob - I've only ever used clay/verm/perl. I allowed the cob to be a little wetter than usual because I wanted to make sure the outside there was nice and smooth...but it seems to me that doing cob this way might crack and fall off into the bottom under the barrel? Has anyone ever toyed around with using different variations of cob mix to do this?
|
|
JJ
Junior Member
Posts: 56
|
Post by JJ on Oct 20, 2014 13:14:31 GMT -8
Waterglass. Never heard of it. Now you're getting my search fu all fired up. I'll have to look at some of the threads...I've been so out of the loop for a few years...I really need to kick myself in the arse and giddyup and get caught up. You'll have to definitely share pics and conclusions when you do this. What part of the world are you from? I have a keen sense of smell for fire brick Perhaps I could help you find some. I'm in central KS. I have a lot of dense red fireplace brick, though I haven't been able to find any local insulating firebrick. I recently "discovered" waterglass (sodium silicate) by reading through this thread: Fireclay and Perlite, add Fire Barrier or Furnace Cement?If you'd like to make some waterglass, check out this webpage: Make Sodium Silicate. I'll be using "Mimi Litter" brand kitty litter, water, and Sodium Hydroxide. I noticed your italicized word "local" fire brick. Understood. Did a quick search - found this: www.americantowns.com/ks/salina/yp/fire-brick-dealersDon't know if it will help or not - never know.
|
|
|
Post by mscantrell on Oct 21, 2014 4:03:18 GMT -8
Got some firebrick last night. Thanks a million, Jamie!
|
|
JJ
Junior Member
Posts: 56
|
Post by JJ on Oct 21, 2014 17:36:03 GMT -8
Got some firebrick last night. Thanks a million, Jamie! Was that you in the silver car? I drove by when it was just starting to get dark and saw someone over there in a grey car You bet! Anytime. And it's still there if you're wanting more. I made a few trips today. Will make more tomorrow. I got a ton so if you need more - just get at me and I'll direct you over to my place for some.
|
|
|
Post by mscantrell on Oct 22, 2014 6:47:05 GMT -8
Was that you in the silver car? I drove by when it was just starting to get dark and saw someone over there in a grey car You bet! Anytime. And it's still there if you're wanting more. I made a few trips today. Will make more tomorrow. I got a ton so if you need more - just get at me and I'll direct you over to my place for some. It sure was. I appreciate it! This should be all I need. I've got some 1" thick lightweight ones for insulating purposes, these ones for durability, and a CEB press for non-refractory bricks. Now to put them all together.
|
|
|
Post by wiscojames on Oct 22, 2014 8:10:15 GMT -8
Color me jealous of you lucky Michiganders. That might be a once in a lifetime find...
|
|
JJ
Junior Member
Posts: 56
|
Post by JJ on Oct 22, 2014 20:18:55 GMT -8
This is what my loads look like lol. I'm real glad you found it easily enough. Just an update: the pile is still there. I have to go to Virginia for a Malamute Weight Pull in Leesburg this weekend with my Giant Malamute Cato...so if you're not doing anything, go grab some. The guy said the pile will be gone by Monday - and who knows, you might need them for future projects.
|
|
JJ
Junior Member
Posts: 56
|
Post by JJ on Oct 23, 2014 8:37:42 GMT -8
So in the past, I've always struggled with getting the manifold on the back of the heat riser correct...proportion wise. I've, like I said - up until this point used only stove pipe for the rocket mass heaters I've built. This is my first fire brick heat riser. It's made of the high end insulating brick.
I've read a lot of stuff about the manifolds. I've seen a lot of different opinions. What has been thus far...the best dimensions for that manifold? I suspect Peter would be best giving me some math on this one....
Also, just for specs knowledge here:
My heat riser is 9 by 8.5 and is 43 inches tall. My burn chamber is 9 inches wide, 6 inches tall and is 7 inches from the feed to the beginning of the heat riser opening (16 inches from the feed to the back of the heat riser).
When I make the double bell thermal mass...how large am I going to have to make the passages going into the manifold, out the manifold and between the bells in order for the thing to work right? I have 8 inch stove pipe that I wanted to use after the bells that go out into the external chimney...but if that's too small, I can go with something bigger - or make the whole thing (except the chimney insert (which has to be 6 inches if I leave the brick wall as it already is constructed)) out of brick. Either way...what kind of dimensions am I looking at here?
|
|
|
Post by Donkey on Oct 23, 2014 12:51:35 GMT -8
8 inch pipes (or passages out of brick, cob, etc.) will be fine from bell to bell. If you are going with the half-bell bench thing, you can just cut them open to each other (at the bottom to make a double bell system or completely to make a single bell). The manifold is more difficult to describe. Peter already did a great job of it in the Helpful Hints thread. I can add to it all by saying that the manifold does NOT need to be carefully defined, it just needs to NOT fall below the minimums and become a pinch-point.
|
|
JJ
Junior Member
Posts: 56
|
Post by JJ on Oct 23, 2014 13:47:53 GMT -8
That sounds about right then. I was just afraid of choking it out - but wasn't there something I read somewhere about it being too big and it will choke it out as well....or maybe that was something about the air space under the burn chamber that you made too big...I'll have to go back and look.
|
|