Start of a clay build (Derby)

[Byronius Maximus]

Okay, so after quite a while of not posting, I thought I'd give an update.

I've had the oven running 4 times now and am absolutely thrilled with the results...people aren't lying when they say that pizzas from your own wood fired oven are the best you'll ever have, and I now have a long list of people wanting me to make them pizza! I haven't ventured past pizza yet, apart from a failed (i.e. burnt) bread experiment. Very keen to try a full on roast in it.

So, since the previous post (over 2 months ago!), I have completed the internal clay layer (obviously), then added a layer of vermicrete and a final layer of clay/straw/sawdust. I gave a couple of weeks for each layer to dry and it seems to have done the trick as the oven is holding heat well, though the outer layer is struggling to dry fully in the winter weather.

I haven't built a roof as I'd rather not, for aesthetic reasons, but I don't want to leave it as it is - one person said it looked like a hairy b***ock! So my currrent plan is to render it in the spring once I have fired it a load more times and can be sure that all the moisture has been driven out of the dome. K-rend seems to be the way to go. Until that point, it just has a tarp over the top. Following that, I think I will either go with a simple white paint or may even tile over the top, though I expect that may be too much effort!

In the more immediate future, I'm going to make an insulated door as I'm currently just using the plywood arch form, and a plug for the chimney to correct my cock up on chimney location (see below)

Being the first time I did this, I knew I wouldn't get everything right:

• I think I made the internal height of the dome too large, so the oven takes a lot of fuel to get heated up...for some reason I followed advice to build it taller than the radius of the floor (so it's slightly egg shaped rather than hemispherical).
• I went and put the chimney on the dome side of the door (it is still at 63% of the height of the dome though), which obviously means air can escape when I want to block it off. Current plan is to make a plug for the chimney using some of my leftover vermiculute and some other bits and bobs. Longer term, I may look at whether I can reloate the chimney to where it should be!

Thanks everyone for the advice on this thread and others, you prove that internet forums can be very helpful and friendly places when they want to be!

Some pics below:

[chas]

Jan 4, 2017 21:23:43 GMT Byronius Maximus said:

• I went and put the chimney on the dome side of the door (it is still at 63% of the height of the dome though), which obviously means air can escape when I want to block it off. Current plan is to make a plug for the chimney using some of my leftover vermiculute and some other bits and bobs. Longer term, I may look at whether I can reloate the chimney to where it should be!

Chimney position looks ok to me... a small galvanised plant pot holder over the top will act as a useful cap for a while - may have to be regarded as sacrificial as the heat is intense. A clay one may do the job, dunno if it would take heat better or worse.
Good news! K-Rend is self-coloured, no painting needed.

Chas

[Byronius Maximus]

Yep, I've been using a bucket over the top of the chimney so far but something insulated will do the job better for when I want to hold the heat in as much as possible.
Good news on the K-rend being coloured, though I actually quite enjoy painting...

[tebano]

Hi there

We are building an oven and we have done a box very similar to yours with railway sleepers. We are now in the process of sourcing the clay, I note you had some bags, can you please let me know where you got them from?
How much did you use? we are building a 76cm diameter oven.

Thanks!

Sept 29, 2016 20:21:52 GMT Byronius Maximus said:

Hi,

After many months/years of procrastination, I have finally started an ove build and thought I'd start to post it on here. Only minor progress so far, but I quite like how it's looking.

I bought a load of sleepers for the base:




And after a bit of hacking away at my decking, I've built it up into something that I think will look pretty good in the garden:




If it completely fails, I could probably turn it into a hot tub! I had worked out the dimensions beforehand, but I was still surprised by how big it looked when built up (1350x1350).
Winding back a bit, after cutting away the decking, I discovered that the earth below was actually very solid so was able to just use a few old paving slabs as a foundation, not needing to dig down at all...I was initially stressing about getting this completely level but came to the realisation that this doesn't actually matter too much:



With that in place and a load of angle brackets and jointing plates used to keep it all secure, I've been filling the thing up with rubble. Foruitously, someone down the road has been doing a load of work on their house and had a skip outside with just what was needed. So this is how far I've got and am now debating exactly how to do the next step.



If I have my calculations correct, the inner diameter of my over will be 910mm, based on three layers of 70mm thickness each. Should be easily large enough!

I need to fill it with a little more rubble and my plan to get the plinth/base complete is as follows:

1. a layer of sand on top of the rubble (probably a tarp beneath it so I don't just lose sand down the cracks!)
2. A layer of wine bottles on top of the sand, for insulation. I have had my friends drinking all the wine they can for this.
3. more sand on top of the bottles to create a level surface for my fire bricks to go on top.

So, to those with much more experience than me, does this sound a reasonable plan? One concern is the whether weight of the fire bricks (and perhaps, the dome) might cause unwanted compression in the sand/bottle layers, thereby upsetting the whole thing. Any better suggestions? I am trying to avoid the use of concrete etc as this suits my limited skill better (perhaps I will get more ambitious if I build another one!).

Looking to get around to this part of it this weekend, though I do not have the fire bricks yet as I am struggling to find suppliers in smaller quantities locally (Derby, and I only need 40 ish) - any suggestions?