Finally started

[mnl]

Re: Finally started

Thanks John. It is mostly refractory cement which is how I got the close joints. The thickness is supposed to be no more than 2mm with what I was using. The walls and the vault are done with this, but I needed something a bit more forgiving with the front bricks coming down at the front, therefore used home brew. I had some left over, therefore just put a thin layer over the top of the vault rather than throwing out. Guess I should leave it a couple of days or a week if I can. Maybe next weekend.

Regards

Mark

[chubbybones]

Re: Finally started

Did you cut all your tapered bricks at the arch with a grinder like me?
Heaps of fun eh? If i ever do another oven ill be getting a brick saw for sure.

[mnl]

Re: Finally started

Agree on the fun of cutting bricks with a grinder. I got a 230mm grinder as the small one I had was not big enough to get through the bricks.

The agreement I had with my wife is that if a tool has a use after the oven, it does not count towards the cost of the oven. After cutting my last brick, I was very tempted to throw it out I was so sick of the sight of it and worried about hurting myself with it. I have since found out they are banned on some mine sites because they are too dangerous.

I agree a brick saw is the way to go if I ever do it again.

[chubbybones]

Re: Finally started

Yea the big grinders are far from elegant.I almost clipped my leg on a couple of occassions trying to make compound cuts in awkward positions so you definately need to have your wits about you when using one.

Having said that ,i can almost taste the pizza now so all that effort was worth while.

[mnl]

Re: Finally started

First fire tonight. Just did some newspaper to start the process. As you can see from the photo, I still have some of my arch support inside the oven that it will have to burn out.

[chubbybones]

Re: Finally started

Wow you move along quickly
Nice work mark.Im guessing you're going to move onto the sides for some buttressing now.Are you going with a concrete mix or vermi mix there?
Keep it up
Cheers John.

[mnl]

Re: Finally started

Hi John

Do you think I need to buttress the walls?

If so, was planning on just doing vermimix over some ceramic fibre blanket. I also have some calcium silicate boards left over that I might use for the side and back walls for insulation and just put the blanket over the curved top. I was wondering about making the mixture a with a bit higher cement ratio to give it a bit more strength although understand it will make it not as insulating. Also still deciding what to do with the side walls of the cover for the top and whether to do besser brick walls or just metal stud walls that then get rendered.

Cheers Mark

[chubbybones]

Re: Finally started

Hi John

Do you think I need to buttress the walls?

If so, was planning on just doing vermimix over some ceramic fibre blanket. I also have some calcium silicate boards left over that I might use for the side and back walls for insulation and just put the blanket over the curved top. I was wondering about making the mixture a with a bit higher cement ratio to give it a bit more strength although understand it will make it not as insulating. Also still deciding what to do with the side walls of the cover for the top and whether to do besser brick walls or just metal stud walls that then get rendered.

Cheers Mark

Well at some point you're going to need some support and insulation on the sides i guess,better sooner than later,especially if you are going to start lighting fires internally.
Thats pretty much what i did Mark. I used a 5:1 vermi -mix sandwiched by the oven and some concrete blocks.You may want to opt for either more insulation or thermal mass,depending on your needs though.
If you recall my thread at the start i was going down the route of Alan Scotts original design which basically is a lot more thermal mass than is necessary for the casual user.I opted to change the design for something more versatile to allow for quicker firings and a decent amount of heat retention.So in the end i dont really have much thermal mass at all,just 75 mm all round and approxiamately 125 mm of insulation all around.
Of course i cant yet say how effective that combination is until i start using it regularly but its seems to be a popular formula around here.
You'll work out what suits you best.

Cheers,John.

[mnl]

Re: Finally started

Agreed, I will need to do something, so I should get in and do it, especially some buttressing for the side walls. So the plan for this weekend is:

1. 50mm calcium silicate boards on the flat sides and back of the oven
2. 50mm ceramic fibre blanket insulation (that I picked up yesterday) on the top and other curved surfaces
3. Concrete blocks around the outside
4. Vermiculite and GP cement mixture between the concrete blocks and insulation

If I can get that done in a weekend, I will be happy.

A couple of questions. I have read somewhere on the forum that you should mix the vermiculite and cement by hand rather than in a mixer as it will break down the vermiculite too much. Is this right?

Also, anybody got a rule of thumb how much vermiculite I will need to fill a certain space, ie, how much will 100L of vermiculite make in a 6:1 cement ratio? Just trying to work out how much vermiculite I need.

Cheers

Mark

[chubbybones]

Re: Finally started

Sounds good Mark.I would say thats more than adequate insulation.As for the vermi-mix i think its also a good idea to do it by hand for the reason you've mentioned.I used up 4 bags(100L) of vermiculite.I would say you need at least 3 bags depending how thick you are going.Someone might be able to give you a formula for measuring how much you need.

[mnl]

Re: Finally started

This mornings job was too vcrete the oven. The vcrete is over 50mm of calcium silicate boards on the sides and 50 - 75 mm of ceramic blanket on the top.

How long before I can start driving the moisture out of the vcrete?

[mnl]

Re: Finally started

This is the flue pipe stand I made. Two bits of angle and a bit of bore pipe.

[chubbybones]

Re: Finally started

Looking good !
At this rate you're going to break the some sort of record for completing a pizza oven in next to no time
I would probably let the vermi-mix cure for a few days,i think most ppl leave it for a week.It might be a good idea to put some shade/waterproof covering over it so the sun doesnt effect the curing process too much (depending on how hot it gets there) or in case it rains.
What type of flue are you going for?I like what you did there but the bore seems a bit small? or it could just be the picture.
Keep up the great work and by all means slow down!

[cobblerdave]

Re: Finally started

This mornings job was too vcrete the oven. The vcrete is over 50mm of calcium silicate boards on the sides and 50 - 75 mm of ceramic blanket on the top.

How long before I can start driving the moisture out of the vcrete?

Gudday
With 50 mm of ceramic blanket and FB board the heat transfer will be slow even if they are damp. With a fire in the oven it will be a slow stew rather than "driven". Be really carful with the fires, least you crack your works.
At this time the sun and particularly the wind will do the work safely over a number of weeks.
regards Dave

[mnl]

Re: Finally started

What type of flue are you going for?I like what you did there but the bore seems a bit small? or it could just be the picture.

Just using a stainless flue, single walled, 150mm. I would have preferred a 200mm flue but struggled to find one in Brisbane. I ended up going to a place called Mr Stoves who recommended that 150mm would be enough.

Be really carful with the fires, least you crack your works.
At this time the sun and particularly the wind will do the work safely over a number of weeks.

Thanks Dave, are you suggesting I should wait a couple of weeks before starting curing again to allow the vcrete to dry naturally for a while?