Finally decided on 32in castable dome

[Mullster]

Flue fitting, blanket fitting, vermicrete (again) and mounting the oven front

Felt like a real big day today. Started by creating 3 tabs in the flue to bend back enabling the mounting onto the cast. Whilst grinding the tabs took only a few minutes, the bending and adjusting took a long time. Two main reasons for this - the cast is not perfectly uniform so each tab is sat on a slightly different height of cast. Secondly the grinding and bending is hard to get identical for all 3. I really didn’t mind this process it just took a while. Lifting the flue, checking with the spirit level, lifting down and adjusting, again and again

After that I moved onto trimming my insulation layer of vermicrete under the oven - it was still protruding beyond the firebrick floor in a couple of places and I wanted a nice edge for the blanket to sit against.

I bought the 50mm blanket and it was pretty easy to work with. The Stanley knife cut through it well and I cut triangles out from the top edge so it would sit around the dome nicely. Used every last scrap so not sure what I’ll do for my door (seen a lot of people using the scraps for that).

I decided to use some chicken wire across the flue gallery which was where I had most of my off cuts wedged together so it helped to keep everything in place. I also put a section across the top of the dome which again helped to keep everything ‘attached’ to each other in terms of the flaps of blanket.

Next it was time to mount the oven front - feels like there should have been trumpets playing at that point! I used wire threaded through the hoops I’d embedded in the front to secure the front against the oven, obviously sat on a layer of mortar.

Lastly I made a start on the vermicrete layer over the blanket. More to do but hoping I can finish with a couple of short evening sessions early this week.

Massive thank you again to everyone I’ve learnt from on this forum - You’ve given Me the confidence to hopefully, hopefully, have almost built a good oven.

[mesoiam]

Looking great! Polished arch turned out nice.What are you thinking for drying? Gazebo? Temporary roof?

[Mullster]

Looking great! Polished arch turned out nice.What are you thinking for drying? Gazebo? Temporary roof?

For the last few weeks of the build I’ve got a very simple cover draped covering it. It’s nothing fancy just a plastic sheet hung over a rod. I think it may do me for the moment - but it’s ugly as hell. The aim is a glazed pergola....but that’s a fair sized project in itself - I probably need to think about a temporary structure. Any cool ideas?

[Mullster]

Third session of vermicrete layer - having to do an hour or so each night at the moment - almost there. I get a really frustrating feeling I’m going to run out of vermiculite though! Which would be 300l used on the stand and dome!

[david s]

It gets way easier the higher you go. you can also carve away stuff that's set or fill any low spots with more wet stuff.

[Mullster]

Almost fire time!

Finally finished the vermicrete layer having had to buy another 50l! So so satisfying to get to this stage!

My latest vermiculite purchase was a different grade - 1mm-12mm and was quite a bit finer than the first 300l. It was easier to use and balled up tighter. Certainly easier to mould into shape - especially around the chimney.

So now I’m going to leave it a couple of weeks before starting the 7 day curing fires.

For now I’ve made a temporary frame to keep the rain off. Got the wife fully bought into the covered pergola design so will be starting that soon!

Quick question about the dome render layer - does it need to be Plasterer’s sand or will the builders (that I have loads of) work?

[david s]

Can’t answer that one, because I don’t have local knowledge re your sand composition. Free is always best in my book, so if you have excess that’s what I’d be using. Apparently sands with a variety of grain size are preferable and those with a high clay content are prone to shrinkage cracks. I suggest you call a local plasterer and ask their advice re your sands suitability. I currently have around 60 litres of sand sitting in the tray of my vehicle because there was not quite enough room in my storage bin area. A (or some) local cat has been shitting in it and it’s most unpleasant making a mortar from it.

[Mullster]

Can’t answer that one, because I don’t have local knowledge re your sand composition. Free is always best in my book, so if you have excess that’s what I’d be using. Apparently sands with a variety of grain size are preferable and those with a high clay content are prone to shrinkage cracks. I suggest you call a local plasterer and ask their advice re your sands suitability. I currently have around 60 litres of sand sitting in the tray of my vehicle because there was not quite enough room in my storage bin area. A (or some) local cat has been shitting in it and it’s most unpleasant making a mortar from it.

That does sound pretty disgusting not the sort of mix I’d want for my render

[hughjamton]

Always use plastering sand, it’s the correct sand to use for rendering as it’s been thoroughly washed removing the clay in it which will cause render to crack. Building sand has a higher water demand and that means during the drying out process you are more likely to get cracking and shrinkage issues which has adverse effects either immediately or later on.
It will also have lots of salt in it, this can lead to salt stains appearing on the render. Best to use plastering sand and maybe a waterproofing additive within your mix.
UK only of course.

[Mullster]

Always use plastering sand, it’s the correct sand to use for rendering as it’s been thoroughly washed removing the clay in it which will cause render to crack. Building sand has a higher water demand and that means during the drying out process you are more likely to get cracking and shrinkage issues which has adverse effects either immediately or later on.
It will also have lots of salt in it, this can lead to salt stains appearing on the render. Best to use plastering sand and maybe a waterproofing additive within your mix.
UK only of course.

Great advice thanks - shame I can’t use what I have but there’s not much use making it all nice and then it cracking straight away

[hughjamton]

you could get away using it as a scratch coat.

[Mullster]

How exciting is buying your first bag of logs???

A grown adult shouldn’t be so excited to buy some logs. Maybe it was the bag of free kindling they threw in too, maybe just the fact that I was buying them from the farm shop I’ve come to have an unhealthy love of (the meat is amazing and all organic). Either way that bag of logs has me dreaming of fire and counting down to next weekend.

In the meantime I created a temporary door for one of the storage areas and used a leftover pallet to lift the logs from the floor - keeping them dry and safe before they make beautiful fire for me!

[Mullster]

First curing fire!

Its here! I finally arrived at the point of the first fire! Following the 7 day guide I loaded a few balls of newspaper into the oven and set my first fire. The paper lit easily (no surprise) and it burned well. I used a full newspaper in the end for a fire of about 10 mins.

Ive bought a laser thermometer so had fun checking the temperature at various points of the oven. Saw the dome hit 200F towards the top of the oven so even though it was brief I thought I’d play it safe and leave it at that for tonight. Kindling fire tomorrow.

The flue seemed to work, drawing the smoke up - there’s no soot on the oven front - which feels like a good sign to start with.

I want to reiterate a massive thanks to all of you who have got me this far and encouraged me along the way.

I know I’m not home and dry yet - more still to do before I can taste pizza over and over again.

[Mongo]

Really nice. Love the decorative fascia. That's a pretty big fire. Be careful with paper, it can spike your temp really fast. Do you have briquettes/heat beads? Much easier to control.

Nice work. Congratulations.

[Mullster]

Really nice. Love the decorative fascia. That's a pretty big fire. Be careful with paper, it can spike your temp really fast. Do you have briquettes/heat beads? Much easier to control.

Nice work. Congratulations.

By briquettes do you mean charcoal? I have some of those I could use.

Im really pleased with the fascia - I’m hoping to find some concrete varnish to make it even shinier.