#1  
Old 06-24-2007, 12:01 AM
Peasant
 
Join Date: Sep 2006
Location: Australia
Posts: 27
Default Dome stayed up this time!

Have just finished my dome Mk II after an initial collapse. Thanks to forum advice this version looks more like an dome and importantly has stayed up!

It ain't pretty (trapezoids etc. are out of my league) but will hopefully do the job. See photos attached.

I have two decisions to make now, and would appreciate any comments/opinions :
1. By building a chimney does it add to efficiency/ease of use, or is it mainly aesthetics on an outdoor oven?
2. Undecided about how to finish the dome. My choice is to either use layers of sand and cement render OR use a thermal blanket and chicken wire before the render finish.

Cheers Steve
Attached Thumbnails
Dome stayed up this time!-dome-done.jpg   Dome stayed up this time!-dome-roof-inside.jpg   Dome stayed up this time!-oven-jack.jpg   Dome stayed up this time!-sand-dome.jpg  

Last edited by KISS4me; 06-24-2007 at 12:41 AM. Reason: extra photos for interest
Reply With Quote
  #2  
Old 06-24-2007, 06:02 AM
nissanneill's Avatar
Il Pizzaiolo
 
Join Date: Apr 2007
Location: Adelaide, South Australia
Posts: 1,875
Thumbs up Re: Dome stayed up this time!

Goes to show what that Aussie inginuity can do when you get the right advice.
Well done mate!
Now you can dry it out and start to enjoy thr fruits of your labours.

Neill
Reply With Quote
  #3  
Old 06-24-2007, 08:08 AM
maver's Avatar
Master Builder
 
Join Date: Aug 2006
Location: Puyallup, WA
Posts: 571
Default Re: Dome stayed up this time!

Looks good - it's going to work fine for you. If you can use a thermal blanket you should, sand is a poor insulator as has been described here many times in the past. Chimney? Should help with draw to develop better convection in the oven, but you would not be the first oven to go without. There may be a minor safety feature in having a chimney - it keeps you away from the hot gasses exiting the oven - if you don't use a chimney please remember that the upper few inches of your oven opening are a danger zone when the oven is in use.
Reply With Quote
  #4  
Old 06-24-2007, 04:37 PM
nissanneill's Avatar
Il Pizzaiolo
 
Join Date: Apr 2007
Location: Adelaide, South Australia
Posts: 1,875
Thumbs up Re: Dome stayed up this time!

Steve,
I used a 25mm themal blanket on my 40" Pompeii. Cut it to size and nailed it in postion with galvanised clouts just enough to hold it in position. Then covered it with chicken wire and then plastered it with 3 layers of vermiculite cement. A little difficult to apply and hold on the vertical sections but made it a little stickier with the addition of a little fireclay. Now, after 6 hours of fierce fire for pizzas and 2 hours cooking the same, the top of my oven is COLD. I topped off the third layer with a render which I intend to mosaic tile to complete the oven and also to make it totally waterproof.
See the progress pics on:
http://www.fornobravo.com/forum/f21/...10-a-2119.html (Neill's Pompeii #10)

All the best with your decission.

Neill
Reply With Quote
  #5  
Old 06-24-2007, 05:21 PM
Bacterium's Avatar
Master Builder
 
Join Date: Apr 2007
Location: Adelaide - South Oz
Posts: 560
Default Re: Dome stayed up this time!

good work Kiss4me....go the insulation

After much thought about insulation "I bit the bullet"........ so I'm currently insulating mine - thermal blanket is on and vermiculite (actually used perlite) is underway (gee its a bit tricky getting it to stick on the steep sided parts)

got my blanket for about AUS$120.......600mm x 7.2m roll which is 25mm thick...... had some left over
__________________
Cheers
Damon


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Reply With Quote
  #6  
Old 06-24-2007, 11:40 PM
Journeyman
 
Join Date: Oct 2006
Location: Adelaide, Australia
Posts: 257
Default Re: Dome stayed up this time!

Steve,

Great job and congratulations after the minor set-back. I think I would have just given up or called in the brickie. Pizze just around the corner now!

And it sure looks prettier than mine – have just laid the floor and started cutting the bricks for the ‘floor ring’ today when the rain came …

Would agree with others to include the blanket insulation and perlite/vermiculite concrete before rendering (this from a man who is yet to get to this stage though!) There are numerous references on this forum to the importance of insulation all around the oven, and it makes sense – both for minimising heat-up time and retaining all that heat.

Damon, Neill,

As a matter of interest, where did you get your blankets, and what product did you use? There seem to be two different products available here – one that is a blend of Silica fibres and either Calcium/Magnesium Oxide fibres (like Insulfrax & Superwool 607), or Alumina fibres (like Cerablanket). They all seem to offer similar thicknesses, densities, widths and roll lengths. At this stage I’m leaning towards two ½”, ¾” or even 1” layers of 96kg/m3 density blanket, criss-crossed over the dome.

Cheers, Paul.
Reply With Quote
  #7  
Old 06-25-2007, 05:08 AM
Peasant
 
Join Date: Sep 2006
Location: Australia
Posts: 27
Default Re: Dome stayed up this time!

Thanks for postive feedback.

I am now convinced that I need to use a blanket.
Have not sourced the material yet, so I cannot help you with this Paul.
Neill's advice on how to insulate with 25mm blanket (galv clout sheet on, followed by chicken wire and perlite mix, finished off with render) sounds achievable.

Also convinced that a short chimney is worth the effort.

Will post progress report.

Cheers Steve
Reply With Quote
  #8  
Old 06-25-2007, 08:30 AM
james's Avatar
Brick Oven Merchant
 
Join Date: Mar 2005
Location: Pebble Beach, CA
Posts: 4,648
Default Re: Dome stayed up this time!

When you buy a full roll of ceramic fiber insulation -- use the whole thing. Just put the extra on top of the dome, or in the area between the top of the dome and the vent. It gets hot there, and more is always better.
James
__________________

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Reply With Quote
  #9  
Old 06-25-2007, 03:50 PM
nissanneill's Avatar
Il Pizzaiolo
 
Join Date: Apr 2007
Location: Adelaide, South Australia
Posts: 1,875
Thumbs up Re: Dome stayed up this time!

Steve,
I don't feel comfortable suggesting that we buy materials from another supplier especially when such a fabulous forum provided by Forno Bravo is being used by us to achieve our builds. However, since they are not here in Australia and freight will put a higher cost on the products, contact a company called Thermal Ceramics:
Thermal Ceramics - A World Force In Heat Management
They are an international company and the lady that I have been dealing with in Adelaide is so helpful and switched on, it was an absolute pleasure doing business with them.
They have everything that you will need but they no longer carry nor make fire bricks.
I bought their 25mm thermal blanket 610mm wide by 7.??metres for Aus$77 + GST. They also have a 50mm blanket for the same price but only half the length. I decided against that as I wanted a hard surface which will be tiled to ensure waterproofing a little later.
I only put a single layer of the 25mm blanket on but have around 1 metre left over which I plan on using some for my doors. I also used the corner offcuts to pack in around behind my lights to protect the wiring from the heat. It works well.
If you tack it on with the galvanised clouts, position them into the softer mortar but don't hammer them all the way home. I only tapped the heads flush with the blanket top. The chichen wire can be distorted and squashed in ares where it is too wide, just keep it thin so that your steel cement trowel doesn't catch on raised wire which will cause the vermiculite to fall out. I found it easier to put some vermiculite cement on a brickies trowel and then push it off onto the dome but just below the areas where it is holding on.
It is quite difficult to get the vermiculite cenent to stick to the blanket, however if you start at the easy top section and work your way down and around but ensure that you keep dragging your trowel upwards and onto the area that has gone on OK. If you change your direction, it will simply fall away and get you rather frustrated. It was on the second layer that I included around 50% as much Fireclay as cement into the mix which makes it a little more stickier. The mix I used was 5 vermiculite:1 portland cement:1/2 fireclay. Remenber that fireclay is also a good absorber of heat so i wouldn't use it all the way through the vermiculite layer as it will reduce the isulating properties. I only used it through necessity on the vertical areas and only on the second and third applications, ie after the blanket and the first vermiculite layer.
Don't try to make the layer greater than 25mm as it simply will fall off on the vertical areas, but if you keep it around the 1" mark, you will ensure that an even 3" or 75mm will be all over the dome. I put the second and third layers onto very fresh previous layers to ensure better adhesion, rather than waiting a week between layers. It only takes around an hour for each layer so one in the morning and one in the afternoon and then again next day wil see a good dome covering. It took 3 bags of vermiculite for the dome insulation which is also available from Thermal Ceramics (Aus$26+/100 litre bag). The final layer was plaster sand 3:1 portland cement and this went on easily in a 1/2 - 3/4" layer which will waterproof the dome and a great base to glue the ceramic tiles onto.
If you want, do as James suggested and use the last bit of blanket over the dome top - vent area, where you have the hottest fire.
If you want any other help please feel free to contact me direct email or through the forum. I am more than happy to help you (or anyone else).
Good luck.
Neill

Last edited by nissanneill; 06-25-2007 at 03:58 PM.
Reply With Quote
  #10  
Old 06-25-2007, 05:03 PM
Bacterium's Avatar
Master Builder
 
Join Date: Apr 2007
Location: Adelaide - South Oz
Posts: 560
Default Re: Dome stayed up this time!

Neil, thats a good price on the thermal blanket(approx.$85 including GST).....your about $35 in in front of me ....AUS prices that is.
I got mine from Avero (previously called Alphacon). He was able to get all the stuff - blanket, firebricks/blocks, clays and other heatproof coatings.

Vermiculite/perlite was about the same, I got it from the local landscape supplier.


Couple more things on applying the thermal blanket.
The 1inch thick stuff was a bit bulky to work with so had to be patient to shape it. I just laid it on and where there were any joins I over lapped it and put wide strips of blanket over them. This actually helped it all hold in place, so I could then carefully put chicken wire over the whole lot (large single sheet). Then I carefully stretched/pulled the wire past the blanket and used masonary nails into the brick edges (below the blanket) to secure the wire. I suppose the trick is not to compress the blanket as that would reduce the thickness and potentially reduce it's thermal capability.

I have most of my perlite on now and when thats done I was thinking of adding another layer of chicken wire over the top of that. Hopefully this will help my render (stucco) coats to stick on nicely.

At the time.....because I hadn't decided on my exact method of insulation I actually cured my oven at the dome only stage (I had a chicken wire/mortar capping on it) and then used it for about 2 months. This was kind of a good thing as I noticed how much heat actually being lost.
I'm guessing I don't need to recure it as the blanket/vermiculite layers will keep the heat away from the outer render (stucco) coat as it undergoes its own curing.


......I'm going to do part 2 thread of my oven progress soon. Hendo I'll try and put the details of things like what type of blanket I used etc......stay tuned Redgum Roarer Part 2..........sorry kiss4me - hope you don't feel like I'm hijacking your thread.
__________________
Cheers
Damon


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
A Potential New Low Dome Design james Pompeii Oven Construction 17 08-14-2008 12:44 PM
Connecting front to dome whocanitbenow Pompeii Oven Construction 8 06-08-2007 07:20 AM
Casa 100 Dome Help dalucca2003 Modular Refractory Oven Installation 6 05-09-2007 02:12 PM
Dome Angle Question james Pompeii Oven Construction 0 01-17-2007 01:26 PM
help 4.5 vs 9 inch bricks for the dome kambos Newbie Forum 5 05-02-2005 10:51 AM


All times are GMT -7. The time now is 07:53 AM.

Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
© 2006/10 Forno Bravo, LLC