Final layers and decoration of the bread oven (5)
This is part 5 of How to Build a Free-form Bread Oven. See here for (bread oven principles, plans and construction recipes (part 1), how to build the base of a bread-oven (part 2), how to build the oven floor (part 3), how to build the oven dome (part 4), make your own oven tools (part 6) or cooking in your bread oven (part 7).
To decorate your oven with tiles or other objects, mix a small, firm amount
of refractory mix. Apply some to the surface. Lay the tiles in it and build up a little mix around them to hold them in place, but only about halfway up the tile edge. (Click on top image right). The final waterproofing layer will be the grout that smooths off around them. Use a straight edge over the tiles to make sure they are level with each other.
On the back of my oven I have a map of my country. I took the plastic mesh of an onion bag, cut it and laid it open flat. I drew a map of my country on a piece of paper, laid the plastic mesh on top and then glued small stones to the mesh and paper in the form of the country. Once it was dry I tore away as much paper as I could. The map was then attached to the oven dome with a little refractory mix at the same time that I laid the tiles. The final waterproofing layer became the grout that held the stones in place.
The waterproofing layer
1 kg milkpowder
2 kg hydrated lime
0.25 kg cement
0.5 kg fine sand
handful salt earth or loam for colour (this will give a natural earthy colour). I added white and yellow-ochre oxides instead.
Mix with water to a firm consistency and grout around the tiles and any other decorative objects. Wipe any excess on the tiles off with a damp sponge. Continue over the whole of the dome and around the chimney base, smoothing it off as you go with your gloved hands (see right). Moisten the mixture a little if it is too firm to spread smoothly. Once finished, check the tiles again and wipe off any smears with a damp cloth.
It really looks as though your oven is completed ... but DON'T LIGHT THE FIRE STRAIGHT AWAY.
Concrete takes at least three weeks to cure. If you light a fire now, your dome will crack irreparably. Use this time to make the oven door and buy
or make some implements for cooking in your oven.
The bread oven door
The oven door is cut from a 70-mm slab of untreated timber (preferably heart wood for endurance). Make a plan of the door hole with a piece of cardboard. Draw this on the timber. This will represent the outer side of the door. Set the saw at an angle so the inner face of the door has a smaller radius than the outside face (see above right). This means the door will always fit somewhere within the door hole, whether it is wet (swollen) or dry. Because the door is made from thick timber and has a flat even base, it sits vertically on its own.
A handle can be made by hammering on a a piece of 50x50x120 mm timber. I found a lovely old hand-forged handle in a second-hand shop and attached it with copper electric cord saddles.
To make bread-oven cooking tools and cure your oven before cooking see part 6.