Started my first build/ garage rocket.....will this work???

After lots of reading and pondering I have started working on a garage heater, It will have no mass as I will only be using it for fast heat while Im in the garage during the cold months.

I have 30 hard half bricks, just ordered 25' of 1"x24" ceramic insulation, and found my radiator barrel (old bbq smoker)
I got my mig welder converted from flux to gas and its doing ok with the smoker barrels.

The core design I came up with leaves me with a 4.5" x 6.5" burn chamber/riser.... The only brick that will need cut is the one on the end and it needs 2" trimmed off.... this 2" piece will fit the gap in the saddle area of the J.

I originally only planned to use the large bbq tube section but need a way to take it apart so now plan on building the core in the bottom smaller section and having the larger barrel section removable with a ceramic fiber gasket inbetween the two and use lock latches to hold things tight.
My concern with using both tube sections in my design is I will have to get more bricks and will have a pretty tall riser. Both tubes stacked ontop of one another is 52" and after I add steel casters the whole unit will be 56-58" tall.
Any concerns or flaws with this height using a 4.5" x 6.5" core/riser?

I plan to weld up a steel box that will be 1" wider/taller than the core, this box will be lined with ceramic insulation and the metal box/core will attach to the bottom chamber with brackets or slide in/out of welded in channels.
I plan on wrapping the riser with ceramic insulation and keeping it in place with a vent pipe or chicken wire.

I havent figured out how I will keep the bricks of the riser secured, would fire mortar or a steel bracket setup work better?

Exhaust will be either 6" or 8" and go straight up out the roof about 12' total exhaust height.

Any suggesstions or concerns with my setup?
Appreciate the feedback...thanks!

How about just a couple simplified questions....

Will the core in a thin gage welded steel box with insulation around the core be ok?

And how rigid would the riser be if I just used a refractory mortor or cement? Would it hold together good enough for handling?

Thanks guys

not sure I can help, but I feel your pain in not getting a response!

What would I do in your situation? Try it, outdoors if needed (ie depending on what is happening with exhaust gasses)

As far as I know, the height of the riser is not 'super important', possibly better to be longer than needed than shorter. Too long I guess would be when it no longer contributes to complete combustion yet robs heat from the exhaust. I would not be nitpicking that aspect until I found evidence to do so.

An experiment does not require the presence right now of the complete insulation, as whatever happens the heat needs to be into the bricks before insulation helps. So, for a finite amount of time at least, the performance will be the same insulated and uninsulated. How long that is I have no idea, but you can certainly test things like draw etc etc right now with a test burn.

Is it meant to be portable? I am trying to understand why the rigidity of the riser is important to you. If it is not being moved then gravity should do it's job. (I can't see the pics as I type so cannot refer back)

Anyways, as I said I personally would just fire it up using what you have and see if you need those extra bricks. Plus it is fun, even if a bust in some way. Most importantly it starts to give you the data you are trying to gain 'in written words', which is never as good as hands on experience.

good luck, hope others more knowledgeable chime in

EDIT having posted I could see the pics again. If your riser stacks as well as the bricks you have stacked, then I would think it perfectly fine rigidity wise if once built it does not move. Especially for experimenting purposes, very thin clay slip is perfectly adequate, no need just yet for refractory mortar or cement.

start burning!

Well, I really don't understand where you are heading. What is the slit on the partition between the "barrel" and the smoker? for example.

One thing I can tell you, if you think about relying on rocket smoke for smoking anything, you will be disappointed.

A little drawing of what you have in mind would be nice.

Lol.... I guess I should of explained the openings in the tube sections.
Thats where the doors were and havnt welded them on yet just incase I needed to change dimensions or anything. There are other slots and holes in the two sections ive already welded in. Not wanting to smoke anything lol....these tube sections are just salvaged from an old smoker and used for the core and radiator

I havent fabricated the steel box for the core yet but it will be in the bottom section and the top larger section will attach to the top with latches and a ceramic fiber gasket.

I guess ill just test my core before cementing. Ill try to add pics and a sketch tonight.

Thanks for the replies!

.........

Hopefully these pics explain it better.

There was a guy on youtube and on here named zerofossil fuel. He made a workshop heater out of a small air compressor tank...it had no mass. Im doing the same thing but on a larger scale. And instead of fiberglass insulation im using ceramic insulation.

In the pics I just have the floor of the core in place. It will end up with sheetmetal welded, encaplulating the core with insulation sandwiched between it and the brick core.

The bottom section with have the core cemented and insulated.... top section will have a removeable riser that will be either held together with cement or a steel frame and insulated.

I want a semi permanent unit that could easily be broken down and moved inside the house if needed for a shtf situation.

Heres the bottom section after I used a cutoff wheel to remove the material and left a 1" lip for gasket. Still need to do the same on the top sections bottom.

Pic of weld using cheap $280 campbell 100a mig welder. This welder sucked using flux and finally after having it for 5 years I sprung for some gas and a regulator and wow! Its like a whole different machine now.

Last pic is with the cores bottom plate installed. Still need to build the cores box before welding it in.

The 3 above pics in previous post are a mockup of my core in the bottom barrel.

Going off memory I think my core is 4.5" x 6.5" ..... should I go with a 6" or 8" exhaust?

Dan, one question, what will you use for a heat riser?

Two or three points. Are you sure you will have enough of a barrel gap? Once the insulation is fitted?

Are you sure the plenum or transition from "barrel" to exhaust will have enough surface? You have never heard of ring projection, do you? Any sense of what boundary layer does in elbows?

Are you sure you have enough exctraction surface?

Regarding your exhaust pipe, you can use 6 inches, since your system could be considered a 5.40.

Mind you, i warn you again, the plenum or transition from barrel to flue should be bigger, at least 150% CSA.

And zerofossilfuel is giving me trouble. The guy has good ideas. But, rocketwise, he has given us nothing but trouble here. I mean to the mods. Every now and then, a guy comes here, saying:

"i've seen such and such from zero, and it's soo cool" and then, starts the battle to explain that metal cores don't hold. That shallow and wide burn tunnels don't work well, nor angled feeds etc. May be not all his fault. But he's part of the problem. If these "rocketeers" could explain in their videos, what is CSA, ring projection, plenums, extraction surface, barrel gap, top gap, direct heat, and stored heat. Boundary layers. Turbulence in elbows. Friction, stack effect etc. That would be sooooooo wonderfull!

The heat riser will be made of the same firebrick and wrapped with 1" ceramic insulation and will be 2-3" below the top plate . I planned on welding a 8" or 10" sheetmetal box for the exhaust port at the bottom back of the bottom barrel then running a 6" pipe straight out the ceiling for exhaust. Should this exhaust port box be larger? There will be no steel in my riser or core just using it to frame in the firebrick and insulation.

Do you think the area between the riser and barrel is not large enough? Should I downsize my core/riser for a bigger gap?

8 inch sheetmetal box, with no protrusion sticking out in the barrel should be fine.

Well, Brick heat riser, with 1 inch insulation should do the trick. And have the proper gap. Tho, by my gut feeling, i think 1 inch insulation is not enough. But i have never worked with cerablanket or superwool.

I got that there won't be any steel in the flame pathways. To save you labour. I think holding the J at the bottom is good. But you could use chickenwire to hold the insulation on the riser. JMO.

And, i used to have a 5 incher, with 2 35kg gas bottles as barrel and bell. This was not enough heat exctraction. This was 2.4m² or about 26sqft of exposed barrel surface. That's why i was thinking that if your barrel gap was too small, you could increase the size of the barrel.

But appart that. All sounds good.

Thanks for the replies!
Ya I was thinking of maybe adding heatsink fins to the barrel to help disperse some more heat and maybe a fan behind the barrel blowing torwards center of garage.

What would be good to use to shield the walls in th3 corner of the garage where this will be going? I was thinking cement board or whatever its called. Its used for bathrooms where tiles will be used.
Is there a more preferable material?

Prety much anything could be used, as long as you leave a convection air gap behind the protection material.

Building code calls for a sheet steel shield, spaced 1" from the wall on metal spacers. The tile backer should work fine, though, as long as you do give it that 1" space so heat can be swept away by air circulation behind the shield.

Ok thanks guys

I want a semi permanent unit that could easily be broken down and moved inside the house if needed for a shtf situation.

I like the way you think Dan. Good job. are you going to put it on wheels. I put wheels on my Rocket Mag Stove. check my links, youll see what im talking about. Totally a SHTF heater for sure.

Dan Cunningham wrote:Thanks for the replies!
Ya I was thinking of maybe adding heatsink fins to the barrel to help disperse some more heat and maybe a fan behind the barrel blowing torwards center of garage.

What would be good to use to shield the walls in th3 corner of the garage where this will be going? I was thinking cement board or whatever its called. Its used for bathrooms where tiles will be used.
Is there a more preferable material?

Dan, by the way, on the fins. I'm not sure they would work. I don't know if the limitation is the speed at which the metal can absorb heat, or if it's the speed at which it can release heat to the surounding air. If the later, fins would work. If the former, only increasing the colecting surface would.

I did end up welding 5 metal castors to the bottom but not much more progress due to the unusually early hot weather weve had and the ol ladys truck needing new brake lines.

Got some more bricks for the riser and some refractory cement.

Just need to buy some sheet to finish the core box and then Ive got everything up untill I build the exhaust.