My first casting

[Bobwieser]

Here are the imiges from photobucket I hope I do this right.


I followed Peterbergs 6' batch design with an extra 10" for easy loading of 20" logs. The walls are 1 1/4" thick, it is made of Kaocrete 250c dense castable. I made the mold of scrap wood and it is ready to be used again. I have a fue changes for the outside shape. It is strong and I plan to use it outside for testing without any backing except insulation. If it holds I,ll move it for inside heat. I hope to do a better job next time with mixing and vibrating with what I have learned but that will have to wait since I figure I might find aditional things to change. I have sketchup drawings of the parts I made the mold with if anyone wants them.
I clamped the 2 halves together w/o a gasket, rested a 5" duct on for a riser and started burning. It has a nice Ram Horn flame patern and little smoke.
Next comes the insulated riser. I have Kast-O-Lite 26LI for that. Its an insulated castable refractory. I plan a 6" ID and 12" OD for a 3" thick riser. I'm not sure if a 12" Sonotube will hold up so I'm thinking of using 2) 6' ducts connected for a 12" outer form. I would love to find an empty grease barrel, no luck yet. Not sure what I'll do for a door, I looking on Craigslist for a cheap wood stove but maybe I'll have to make something. Hope my pics and vid come through. Please tell me if you see issues whith my plans. Thanks, Bob.

[matt walker]

That looks fantastic from here Bob, you do nice work. There are some doors from masonry heater suppliers that will work, but they are pretty spendy. Another option for doors is ebay. Search "cast iron door" or "iron door" or "coal door" or variations of that theme. There were a ton of old industrial furnaces and even domestic heating set ups that had small cast iron doors, which are now in antique store type circulation. I've found some cool ones for <$50.

Try this:
http://www.ebay.com/sch/i.html?_trksid= ... &_from=R40

Your plan sounds great so far, but one caveat of that firebox design, make sure you have a good chimney and that you don't load the heater too much with too much bell area or too long of flue runs. The batch box is a finicky one to mate to the rest of the system in my experience, much more so than a J. I'm not trying to scare you, far from it, I love that design. Just be ready to work a bit to get it to do the same thing it's doing now once it's pushing heat through mass.

[Bobwieser]

Thanks for the kind words on my mold and the link for doors Mat the spendy part is not in my plan. Remember I was hoping to use granite muck for clay? I found a deal on refractory so thats what I used. I just keep going back and forth between J and batch feed for my indoor setup. I am leaning towards bells or just radient heat instead of a bench since I'd like it to be compact. I like that the J has a much smaller fire going but the batch should not have to be spoon fead as often. I want to see how intence and potentialy scary the fire is in a batch. I'm hoping that I made something that can be taken apart, moved inside and set up again. I figure if nothing else it will be nice to have heated out door seats. I have a builder box fire place with streight 8" metal chimny with lots of draft so if I hook up to that I'll be good. There are many flaws to my set up as it sits like leaks between the halves , small uninsulated riser, no door, secondary air is blocked with a brick and fiberglass insulation, I'm thinking those hurt with draft and smoke back. But no barrel or flu runs help with that. As I progress I'll have a bypass for starting cold and see how things work. Are the batch rockets more prone to smoke back than the J tubes ?
I'm hoping to cast a dence strong 2 piece 8" J some time soon. Likely I'll use foam for the mold since the optimised shape does not seem to allow saving the mold as the batch shape does. It's fun to play with this stuff.

[mannytheseacow]

That looks really nice Bob! I was hoping to see what that granite dust did but it looks like you found a great mix to work with instead. I'd be curious to see how you made the mold out of wood. I don't know too much about the batch boxes and there aren't any good videos for the batch box like Matt's for the J (not that I've looked very hard).

As for a door, I've got a door off an old stove laying around. If it works for you it's yours. Let me know if you'd be interested and I'll take some pictures and measurements.

[Bobwieser]

Yes Manny I'm interested in the door. My feed opening is about 9" wide and 13" high. I ripped the wood in shapes and screwed them together in a way that I could take it apart after molding. I used shortening and Pam as a mold release. The aftrenoon I did the mold was perfect, sort of warm and dry. I used cold water to slow the working time and then added too much water for the first mold and also had to scrape every bit of the 110 lbs to still come up a little short. The second mold was better I used 125 lbs and mixed for a lot longer with less water and it came out better. It's true that it's a knife edge for too much water with this stuff. I had a borrowed Harborfreight vibrator that I used but I had both molds on the same base on 2 tires so I had to vibrate for a long time to get the air bubbles out. That likely caused much of the agregate to settle. Just another lesson learned, cant buy experience can you? No pics or videos of the molding sorry I was too focused on the task at hand. I was like a kid at Christmas waiting to open it up. It was outside and there was 2 nights below freezing so I put 3 100 watt light bulbs under and some moving blankets over the molds.In spite of it all it's not bad but I know I can and will do better. Lets see if I can post the Sketchups I have. I can also take pics of the molds and post them on photobucket. My internet connection is by my cell phone so its slow so please be patient. I did upload "my first burn" if you want to see it. It's sideways and not of any quality but you can see no smoke from the riser and a good fire going. I'll include my drawings next post incase I mess up.

[Bobwieser]

Sorry I have not attached a Sketchup yet and I'm strugling with it now. Any sugestions? I'll try again tomorrow.

[mannytheseacow]

Well cool, if the door will work for you, PM your address and I'll send it to you. The frame measures 16.5" wide at the widest and 14.5" high. Where it rounds to the skinniest width is 14".

The actual door/opening measures 11 inches high by 10" wide at the widest and rounds to 8.5" wide at the top and bottom. I'd love to see it used for something besides rusting in my yard. I had some dreams of using it for the same thing someday but I'm getting married in a few weeks and already trying to downsize all my stuff not to mention combine two households. I'm definately building 2 more rockets this summer but probably not doing any more experimenting for a while.

[matt walker]

Congrats Manny! You sly fox! Bob, I don't think you can attach sketchup files. The best way to share sketchup ideas in my opinion is to export your work as an image and just post it here as a pic. That way we can all see what you have designed without having to use sketchup. We won't be able to spin it around and see it inside and out and stuff, but if someone wants the skp file itself you can send it to them using dropbox or wetransfer or something like that. Frankly, sketchup gives me fits, not due to any shortcoming of the program, I just get instantly frustrated with it, so I never see people's ideas when they post skp files. I much prefer an image.

Manny, if you or anyone else wants a video of casting a batch box the "wrong way", I'd be happy to make one. I prefer to make them in one piece just for convenience sake, and can whip up a mold and cast one in an hour or so. I have hesitated since the right way, as Bob has done, is really truly the right way. I just can't be bothered with that much detail when I'm on fire with an idea I want to try.

[Bobwieser]

Congrats Manny and thanks for the offer, I think the door will work for me. Yea Mat sketchup can be frustrating for sure. It's all new for me too, just as photobucket and other ways of shairing ideas. The many other things I'm learning on this journey. I havent figured out the "drop box or wet transfer" yet so here is photobucket of most of the innards for my mold. I can take some pics and upload those too.

[mannytheseacow]

This is really helpful, Bob. Your drawings give me a pretty clear idea of what you built and how. A couple of questions I'm still fuzzy on with the batch box design:
1. Typically I see these with the angles in the bottom of the firebox. I've got Peterburg's sizing calculator that tells length/width/depth for the firebox but how do these angles fit with that? Do you oversize the height to accommodate the angles? Then by how much?

2. The p-channel is the space at the back top of the firebox, right? In a realistic application with a well insulated chimney, wouldn't this space be covered? If not by the insulated riser wouldn't the barrel sit over it? Or is that where it's supposed to get the secondary air from, inside the barrel?

I'm sure these answers are somewhere on Donkey's site but I get so frustrated looking over there. There seems to just be too much other neat stuff distracting me on that site!