Our garden is the perfect BBQ spot, a national obsession but when the sun goes down behind our house a 5 o'clock it get's cold straight away thanks to the always prevailing winds here.
I wanted to have a fireplace in the garden that would allow our guests to stay comfortable,
so I made a Chimenea, the Mexican wood burner, not from clay or adobe but from concrete!
I was told imported Mexican chimeneas were popular here for some time a couple of years ago but the clay is not really resistant to this climate. Water would seep into the cracks, the bottom would fall out at best and at worst they would explode. (Not a pleasant thought.)
I would buy a proper one but they are not available cheaply here and besides, where is the fun in that?
Large amounts of clay were not easy to find cheaply and while searching the web I read about ferrocement: plastering ordinary Portland cement on a mesh of chicken wire. With this interesting technique one can create all kinds of forms that are very strong, cheap to make and relative to its size reasonably light. Because is is very labour intensive it is not widely used but during both world wars the shortage of steel they constructed ship's hulls out of the stuff, the largest being the SS Selma that weight 7500 tons. (!)
This inspired me to try create my own chimenea from chicken wire and cement.
For the design I was inspired by this Instructable by Tim Anderson of his chimenea made from an old propane tank . I wanted it to resemble a Maori tiki face,
complete with paua shells for eyes. The pupils are formed by holes in the shells and the concrete wall so they will flicker with the light of the fire, just like Tim's chimenea.
I wanted to have a fireplace in the garden that would allow our guests to stay comfortable,
so I made a Chimenea, the Mexican wood burner, not from clay or adobe but from concrete!
I was told imported Mexican chimeneas were popular here for some time a couple of years ago but the clay is not really resistant to this climate. Water would seep into the cracks, the bottom would fall out at best and at worst they would explode. (Not a pleasant thought.)
I would buy a proper one but they are not available cheaply here and besides, where is the fun in that?
Large amounts of clay were not easy to find cheaply and while searching the web I read about ferrocement: plastering ordinary Portland cement on a mesh of chicken wire. With this interesting technique one can create all kinds of forms that are very strong, cheap to make and relative to its size reasonably light. Because is is very labour intensive it is not widely used but during both world wars the shortage of steel they constructed ship's hulls out of the stuff, the largest being the SS Selma that weight 7500 tons. (!)
This inspired me to try create my own chimenea from chicken wire and cement.
For the design I was inspired by this Instructable by Tim Anderson of his chimenea made from an old propane tank . I wanted it to resemble a Maori tiki face,
complete with paua shells for eyes. The pupils are formed by holes in the shells and the concrete wall so they will flicker with the light of the fire, just like Tim's chimenea.
Remove these ads by
Signing UpStep 1: Get the components
I always try to work as cheaply as possible, (re)-using second hand parts where possible. It's more fun, lets you be more creative and doesn't hurt so much if the project come out less then successful.
My favourite is The Wellington City Landfill's Second Treasure Shop, a wonderful source of materials and inspiration.
Price list (new & used in $NZ)
from the Landfill's Second Treasure Shop
1 bar stool $3
1 meter black stove pipe $5
1 black cast-iron pan lid $1
1m x 20cm black stove pipe $3
from Mitre10
15m 2.1mm steel wire $2.99
10m x 90cm galvanized chicken wire mesh $44
(Alternatively, use Expanded metal, might be cheaper)
60kg ready mix cement mortar $36
1kg iron oxide cement coloring $11.50
from the $2 Shop
1 Pink Skippy ball (or 'space hopper') $2
2 black wigs $4
tools needed
rubber gloves
pliers
duct tape
tie wraps
cardboard
cling foil
big and small buckets
from Muritai beach
2 small Paua shells for the eyes
15 or so Paua shell fragments for decoration
My favourite is The Wellington City Landfill's Second Treasure Shop, a wonderful source of materials and inspiration.
Price list (new & used in $NZ)
from the Landfill's Second Treasure Shop
1 bar stool $3
1 meter black stove pipe $5
1 black cast-iron pan lid $1
1m x 20cm black stove pipe $3
from Mitre10
15m 2.1mm steel wire $2.99
10m x 90cm galvanized chicken wire mesh $44
(Alternatively, use Expanded metal, might be cheaper)
60kg ready mix cement mortar $36
1kg iron oxide cement coloring $11.50
from the $2 Shop
1 Pink Skippy ball (or 'space hopper') $2
2 black wigs $4
tools needed
rubber gloves
pliers
duct tape
tie wraps
cardboard
cling foil
big and small buckets
from Muritai beach
2 small Paua shells for the eyes
15 or so Paua shell fragments for decoration
Visit Our Store »
Go Pro Today »
Do you have any hints or additions to add to the instructable to improve on what I found out?
cheers,
Matt
you might want to read up on these links:
plus the forum at fornobravo is always a good place to ask questions.
http://www.fornobravo.com/pompeii_oven/high_heat_mortar.html
http://www.traditionaloven.com/articles/101/what-is-fire-clay-and-where-to-get-it
http://www.traditionaloven.com/tutorials/concrete.html
But I think that's because my mix was very rough the begin with (let's of large grit in the sand)
I will post a full project including failed design once mine is complete. I will say that a larger design like mine places a ton of weight on the wire structure, 160lbs of cement on two layers doesn't make much sense now that I think about it.
AL
I used a refractory cement mixture for mine to avoid it breaking down. My ratio was 3 sand, 2 plastic cement (I was told this was stickier), 1 fire clay. I forgot to buy lime and when I called back to the shop was told it was not necessary. What is the purpose of lime anyway?
Completed 3 days ago. Can't wait to give it a try!
My experience is that the chimney could be wider or, that their should be more roof-spanning-space between the top of the opening and the bottom of the chimney.
I'm working on a wood fired pizza oven at the moment and that design is very clear that the height of the opening (or bottom of the chimney) should be set at 63% of the height of the dome. So there is quite a bit of theory about this.
Not sure about the lime. In clay ovens it is used to make a waterproof outer layer. Not sure what it does in cement.
Good luck!
I'm wondering if the walls will become hot and radiate the heat or if the fire clay (refractory cement mixture) will prevent this effect.
As it is, with my chiminea standing 4 feet 7 inches (140 cm) and cement even making up the chimney, it must weigh somewhere around 165 lbs (75 kg). How much did yours end up weighing?
Veel geluk met uw pizza oven!
If you make another use "white Cement" it is used around pools and must have alumina in it it resists fire better. If you have a guiotine for paper you can chop fibergalss insulation to 1/4-1/2 inch threads and mix in the mix to add strength.
if you fill the bottom with sand and line the bottom with splits ( thin ner bricks then standard bricks, you can fire it for hours then after the booze works its magic AND the 3 hour fire finishes up, you can bake a few small pizza's or pita and nan. Then drink more beer, and restoke the fire. If itis wide enough and the pie small (for 1-2 people only) you get some coals going brush to sides and back and slide the pie right in front of it. An edgeless cookie sheet will work as a peel. put the pie right on the bricks. For low use ovens (or this) plain vanilla red clay bricks work fine.
I enjoyed this a lot and may yet build a brick oven soon. Forno Bravo is great and is not cheap, err rather inexpensive or affordable.
a health warning,do not use galvanized metal with direct , near direct contact with fire. It can release zinc fumes that can destroy lung tissue.
using this technique in old issues of Mother Earth News a person built a small out building like your Chimenea
thanks again for the intructable , this was fun and a trip down memory lane for me.
Inside was cool too, trump l'oi pics with mirrors set next them in the walls. On a good night heavy party types would get wacked out and walk into the mirrors or doors (percieved) only to bounce off, Easy way to assume a drinker was cut off for the evening.
see ya
So, perhaps during the summer months a version 2.0.
I'm impressed for the use of wigs...
Years ago I maked a "bell roof chimney" for my BBQ, and I used expanded metal ("metal desplegado" in Spanish) covered with Plasticor, a precast masonry mix.
What is "expanded metal" and why would you use it in this case? I tried googleing it but could not find a quick answer.
Go to http://www.mechanicalmetals.com/expandedmetal.html to see what the stuff looks like and the sizes out there.
For something like this fire place, you have the choice of either welding it into shape, or wiring it together before you cover it with your selected cement. Be aware that this stuff being steel it will RUST as heat aids oxidation, even in the concrete. I suggest once you have the form shaped, spray it with a rust proof BBQ high temp paint to seal the steel, and then cement over this (It will adhere just fine.)
It can be made of distinct metals: iron, steel, aluminum, brass, etc.
This material can be expensive, but with a bit of forethought, you can use only what you need and save money. By the way, with good planning and some rough measurements, most shops can cut this stuff to your sizes easily and cheaply and you save yourself a lot of work.
Thanks for the tip.
L