Troy Fairclough

im from south central alaska, in south anchorage.

i love permies, and am learning and planning my own projects.

working on a RMH for my woman currently.

i absorb everything i learn here and spend more hours than she likes doing it!

Kevin Prata wrote:I'm curious about adding two additional barrels on top of the usual barrel design, to work as stored heat radiators, similar to a masonry stove like a Finnish or Swedish Kakelugn.

The idea here is to have the first inner barrel sitting 2 or 3 inches above the riser, then have another barrel over that one forcing the radiant heat downward, then another barrel two or three inches above that one, with a gap at the bottom, radiating heat up to the top again, and finally a flue exiting out the top rather than the bottom.

Will this improve the overall design, or diminish it? See image here.

it might work., one thing i would be super careful about is to make sure that all of your barrels are big enough.

if any of the areas past your burn tunnel are smaller in overall space than your burn tunnel you wont get draft and the rmh wont work.

as long as you are sure that all of your areas are equal to or larger overall area than your burn tunnel you should get draft no matter what you do as long as you dont go over the total recommended length of an efficient RMH.

i dont have all the answers, im still in the process of building my first, but you should check into what i said and see what you can learn.

jacob green wrote:
Someone really needs to figure out how to burn 6-8 foot fuel in the feed tubes to reduce the amount of refills during the day. I present several ideas in that thread. Maybe you will think of something to add.

thanks again.

maybe you could try using some formed chicken wire above the feed tub to harness longer sticks. however they would probably get caught in it and not lower into the feed tube. just my first thought.

Kevin Prata wrote:Hi Dale, et al

Good morning. Do you still have fire brick and or ceramic heat riser(s)? I am considering one or the other or both for my first rocket stove. I was going to build the core and riser both with refractory mortar mixed with vermiculite or perlite, but the fire brick might be simpler. I am working on a 6" system. Please me know!

from what ive read, your exhaust as you have in this diagram wont work, you need to have a larger bell shaped transference from the drum to the horizontal exhaust.

other than that looks good.

G Fischer wrote:Thanks for replies. Nice to meet you both.

My system starts all brick, like so many seen, and is 4.5" dia. I then
have a 6" steel riser, 11 3/4 tin insulating cover, with vermiculite/slip
insulation, a 40" high propane bell with removable top that is lipped
and sealed with fiberglass rope

(Yes, I smoke checked the top for leakage. Don't see minute leakage,
through the rope fibers at this seal, as a big deal on a down draft system this low on flow.)

Thanks for any future input!

Here are pics on my general combustion area:

you need to post the direct link for us to see pictures.

John Elliott wrote: "4. Is there an ideal ratio for the inner dimensions of the core/heat riser/exhaust? Are there any rules dimension-wise which are especially critical while there is room for experimentation elsewhere? In particular, is the diameter of the airflow path the SAME ALL THE WAY THOUGH the system? Or do you need the exhaust portion of the path to have larger diameter than the core/riser to create lower pressure on the back end, to let the gasses slow down and get burned rather than being rocketed out the chimney cap before getting burned"

your burn tunnel needs to be the tightest of all areas.

all areas past the burn tunnel need to be at least as large as the overall area of the burn tunnel if not bigger.

make sure that where you connect your exhaust to the burning unit that you do not cramp the space at that joinder.

if any areas are smaller in surface space than the burn tunnel the unit will not draft correctly from what i understand.

as far as having efficient burn that all comes down to the height of your heat riser.

my comments are what i have learned in my research, i am in the middle of constructing my first RMH so i dont have every correct answer, just trying to be as helpful as i can.

You should be able to purchase fireclay from lowes or home depot im pretty certain,

i called a sand and gravel yard and they had a better price and i like to support local when i can.


i am in alaska and i was quoted at 27 dollars for a 50 pound bag of fire clay.

i have also seen it said many times that using some furnace cement while pouring your core helps to harden it.

i have the plans for my core up in the other thread.

Kevin Prata wrote:Hi Matt -

What ratio of furnace cement are you using? Just curious. I was (am) planning on a vermiculite + refractory mix at a 4:1 ratio.

Regards

K.

i think he says 14 parts clay 14 parts perlite and 1 part fire cement.

seems like you should be able to do more for the sturdiness than just adding such a small amount of furnace cement.

now i am in hiatus again until i do more research. i really want this to be perfect and well built and the only way to allow that is to take your time and make sure each part is right

fired my 55 gallon drum last night and drank beer till 430 am. it was a lot of fun.

all the paint except for the very bottom burned off. ima take it to a wheel grinder maybe on monday

enjoy your weekends all

Matt Walker wrote:

Troy Fairclough wrote:
this is the mixture i am using

http://www.backyardmetalcasting.com/refractories.html

very similiar to the one posted in your video which i have also watched, but i think it will be harder and more durable.

Hi guys, that's my cast core video you linked to. Just a quick note, I've tried the backyard metal casting mix exactly as written there. It turns to powder after not very long as the heat breaks the bond in the portland. I'd strongly recommend leaving Portland out of any of the real hot areas.

what cement would you suggest?

also i have decided that the end of my outside box are just not wide enough and will be increasing my outside box size by 3/4 or 1 inch before pouring so it should measure 31.5 or so after i make the modification

i think three inches on each side and 4 on the bottom is enough size to lend strength and heat resistance.