Completing your Wood Fired Oven | 3. Understanding Cracking
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- Опубліковано 1 жов 2024
- Small cracks are and always has been a part of owning a Wood Fired Oven. In this video we take you through the common cracks you're likely to see in your Wood Fired Oven.
Please note that it is completely normal to see some hairline cracking in your oven, in fact we can guarantee that you will! This is because you’re heating up a rigid, ceramic structure to extremely high temperatures, which creates thermal stress in the brickwork. To relieve this stress, the oven will develop several small cracks, usually around 1mm in width. It’s common to see a crack starting at the base of the dome that runs all the way up to the keystone, as well as some fine cracks in the mortar joints of the Vent Arch, and around the Flue Gallery. You’ll also see some cracks in the Perlite Render radiating from the junction with the Flue Gallery.
Don’t let these cracks concern you at all. You should be expecting them. This cracking is normal and there’s nothing that you can do to prevent it. Cracking is and always has been a part of owning a Wood Fired Oven. What’s important to know is that they won’t get worse over time, they’re just there as thermal stress relief.
If you get a large crack in your mortar (over 2mm width) then we have repair materials that can be sent out to you, however this is rare, and is usually due to the oven being over-fired early in the curing stages. Any cracking in the Perlite render will be covered by the roll-on acrylic coating that you’ll apply once the oven is fully cured.
Our Wood Fired Oven Kits are available in Australia, the USA and the UK! Check out the links below:
Australia: melbournefireb...
USA: www.flamesmith...
UK: www.kennedyfir...
CREDITS
Videography and Editing by SUB AERO MEDIA: www.subaero.me...
I am stunted how transparent your company is, Bravo! You are clearly not just selling, you really introducing your product.
Thank you! That's exactly what we're trying to do - I like to know exactly what I'm getting when I purchase something, so we want to treat others the same way we want to be treated. Thanks for the encouragement!
Wonderful series of videos, very informative! In the Understanding Cracking video you mention a product you have that can be used to repair larger cracks, larger than 2 mm. Would that be Ultrafire crack repair for wood fired ovens? As you mentioned, I have the slab cracks and they do go down into the concrete block stand, confident they are not structural. My concern is cracking around the base of my oven dome where I have it cemented to the slab. I have some long 2 mm cracks in my outer render, as well as many hairline and 1 mm cracks. Was hoping the Ultrafire repair compound is the preferred product, or something that is similar. It is applied when the oven is heated to about 280C or 480F looks very much like the acrylic render you use to seal the render layer. After using this on the cracks I would then apply an acrylic render or elastomeric paint over the whole dome. I'm in the US so we lose something in the English to English translation of product names and such. Ha! I do have big concerns about water as I live in Florida where it is always humid. Thanks so much for all the information!
Good question Russell - our repair material is more for repairing cracks between bricks, which is a special refractory mortar mix with no aggregate.
If it's just cracking in the external render layer, I would be getting some Behr Premium Exterior Elastomeric Coating onto it, as I don't know if many materials can be applied over the Ultrafire material.
Hi there I have started to fire up my wood pizza oven I saw same small cracking on the dome. I. Quiet worried about Is those hairline cracking are normal. Or is there anyway to fix or to avoid any big damage
Don't worry - hairline cracking is completely normal in a brick oven, as much as we would love to avoid it! It's a rigid masonry structure that's being taken to quite extreme temperatures so it will experience significant thermal expansion and contraction, and the hairline cracks provide stress relief for the structure.
Excellent video
Thank you very much!
I built my pizza oven. I too have hairline cracks that have appeared on the base ( made from refractory cement and without rebars....my bad ). You mentioned a product that you can send out to repair cracks. Do you sell it to anyone or just your customers please. I have thought about making up a PVA / Refractory slurry to do the job. Any thoughts please and a link to your product, if possible. Thank you.
If your suspended slab has no reinforcing in it, I suggest you get some supports underneath it right away. No amount of repair products can help if there's no reinforcing in your suspended slab - please reach out to us at sales@melbournefirebricks.com.au and we would be happy to help where we can.
I am close to completing my oven build and was wondering about firing. I saw your video on that but my question is....I plan to cover my perlite outside with mortar and complete with brick veneer for appearance. Would you recommend doing my firings first before applying the veneer or after applying the veneer? Thanks.
Hi! Emailing us is always the better way to reach us with technical questions like this one, we don't check the YT comments all that often! It would make sense to cure it beforehand so that you minimise the number of cracks coming through the external brickwork. The perlite render will develop small cracks during the curing process, so bricking over it after the cracks are formed may prevent some of those cracks from propagating through
@@TheFireBrickCo Makes sense. Thanks for the come back.
Thanks for your informative videos. I recently built a perlite oven and have possibly overheated my curing fires and now there’s a hairline crack inside the dome starting from the base shooting straight up the dome around 25cm. Should I be concerned about it or just keep on with curing? If repair is needed what do you recommend to use?
Sighs - I imagine you have built the dome using Perlite mixed with Portland Cement? If so, it's going to get a whole lot worse sadly. You can't repair it or line it with anything (it just won't bond properly in the long term). Portland cement breaks down at around 350C so the dome will end up falling apart over time, which is why you don't see many videos showing this kind of oven years later.
Question for you - can I apply an acrylic roll-on render, and then apply thinset for my mosaic? Or is that unnecessary?
Hi Andrew, that is how we would recommend doing it - cure the oven, apply the roll-on render to act as a waterproof membrane, then tile over the top.
I got a precast dome pizza oven got hair line cracks through the dome should I be worried
Hi Brett, reach out to us with some photos at sales@melbournefirebricks.com.au and we will be happy to help!
I recently had the floor of my wood fired oven crack (mini explosion) with a 3 inch circle, maybe 1/8 inch deep. The oven is finished so flipping the stone around cannot happen, what can be used to patch and safely cook on it meeting high temperatures? thanks Paul N.
Hi Paul, that's awful! Who is the manufacturer of the oven? Have you contacted them?
@@TheFireBrickCo I have reached out to the US Supplier for this SUNDAY Volta oven. No response yet. One group I contacted suggested flipping the stone over, really? on a finished oven? difficult at best. Refractory cement possibly? tks
Ben's the best number 1
Hahaha we do both have an outstanding first name!
hi there from california. i just took delivery of a relatively inexpensive clay pizza oven. unfortunately dome badly cracked on arrival. as you are experts, would you pls advise as to the type of material that would be dafe to use on the inside and outside of the dome to fix the cracks? im sure certain chemical compounds may not be safe to subject to heat and next to food... thx for any insights.
Sorry to hear that Jonathan, did the company that you bought it from have any recommendations? Send us an email to discuss it further: sales@melbournefirebricks.com.au
@@TheFireBrickCo Hi guys, thx for your comment. i am going to try Rutland outdoor (dry mix) high temp refractory cement to see if that works. taking delivery of some this week. we shall see...otherwise it will be a build from scratch!
So even if you tile or brick around it obviously it would hide it ?
Tiling will generally cover the cracks so that you won't see them.