How bad did I screw up? Used the wrong mortar

[stonecutter]

Re: How bad did I screw up? Used the wrong mortar

I'm not interested in resurrecting the topic of using red commons in ovens, if that's what someone wants to do, that's their decision. I only wanted to show an example of what can happen if you use reds that are not compatible.



This picture was posted by a friend in a professional forum. As you can see, the box was built using the same red commons as the surround. It is badly spalled and it was totally replaced with firebrick -click for close up. A firebox doesn't receive the same thermal exposure as an oven...and it wrecked the brick. I've seen this before ( never took pics ) in fireplaces and in a couple cases, some of the historic beehives I have restored. Interestingly, none of the beehives are 'reds' but resemble salmon brick, which are fired at a lower temp. They are closer to what was use in the ancient brick ovens in Europe. But those bricks with the same qualities are not readily available today, and 9 out of 10 times, 'Red' brick is designed for cavity wall veneer...vitrified to enhance resistance to water intrusion.

How do you know if the reds you choose are compatible with oven building? You don't, or can't by observation in most cases. It was said that an oven is an investment in time and resources. That is true. It is understood that reds may be the only option for some. It is also true that some reds may survive for years in an oven application. But it is not optimal ( and this is different than 'best practice' too) if you do not know what the reds are comprised of and how they are fired, then you should not use them if at all possible.

That is the point of my earlier comments...not if you should use them or if they will possibly work.

That is all......

[Campmaki]

Re: How bad did I screw up? Used the wrong mortar

And yes Stonecutter is a valuable asset to this forum. If you " one build wonders" have got everything figured out, good for you. If you want professional advice then you can also get that.

[Old_haidouk]

Re: How bad did I screw up? Used the wrong mortar

Update!

Thank you all for offering to help. That's really comforting. Here are a few more details:

The hearth is 5" reinforced concrete. On top of that I set a sheet of Durock after seeing that the components in the Durock were similar to those in heat resistant mortar. I did buy refractory mortar(white stuff good to 2500 F) but I mixed it with Type S mortar, 50/50 ratio. This made the resulting mix to harden up really fast. I did manage to set the hearth bricks with it(I found out afterwards that I should've layed them with no mortar in the joints). I also layed the base of the dome with the mix. I then completed the dome with Type S. The side of the joints exposed to the fire is minimal as I canted the bricks so I m hoping there won't be an immediate problem.
I mixed some yellow dirt with the Type S mortar and plastered the dome on the outside. I did try to find fireclay here N of Chicago but none of the Home Depos had it. Not even the brick yard I went to. So I gave up on it and used yellow dirt...

So this is a short list of my screw ups. I enclosed the dome in a brick house and after about a week of letting it dry I fired it up with a small fie yesterday. Everything seemed well but its premature to determine how well it'll hold up. I noticed the hearth built up heat fast while underneath it was only slightly warm.
The dome got only slightly hot on the outside. I intend to cover it with 4" insulation good to 2000F.

Can you suggest a roof that will provide access to the dome in case of a problem? I wanted to pour a thinner slab as a roof but that may not work well for easy access.

[oasiscdm]

Re: How bad did I screw up? Used the wrong mortar

Some of us don't have the time or patience that the johns, Russell's, kd etc had.
Or funds. I followed these builds and more and used the best took my time, but that is just who I am. We aren't all that meticulous but that is what makes up the world.

[Campmaki]

Re: How bad did I screw up? Used the wrong mortar

Here is my 5 dollars worth, build the thing the best you can. Use what you are suppose to use, if you expect to get any amount of life from the build. People I work with, always say, you can only build it as good as the materials allow. I agree to a certain point in regards to that statement. My thoughts are simple, why put all the time and effort into something that costs you a lot of time and money if you are going to do it half assed,oppps. Did I say that!!!! This site has pro,s and builders who have never touched a trowel in their lifetime. The smart ones will grab the info provided from the site itself along with the knowledge from the pro,s and run with it. If you are going to cut corners or use sub standard materials so be it. It is a lot of work to build an oven, why not do it right from the start. Wayne

[Novaslo]

Re: How bad did I screw up? Used the wrong mortar

Funny, the original poster, has no idea that everyone jumped on the thread like this.

Not being a pro and spending 3 hard months on my build, I have dreamt about it many times. I still think one of my bricks in my arch will fall down and know specifically where the weak points are. Or should I say, the places where I wish that I spent more time crafting properly.

I wish I would have created a larger flu entry.... as an example
I am very glad that I used the right materials and feel strongly that if something went wrong I could easily fix it. Perhaps with steel if I had to.

For the OP - I still think it comes down to - How done is done?

If it is done done - too late, cook ya butt off till it falls.
If it is mid build, go do it right...

That my 2 cents - from a novice.

[cobblerdave]

Re: How bad did I screw up? Used the wrong mortar

It was, but i wasn't aiming it at anyone specifically. Thanks for that.

If you have contradicting advice what do I care?..back it up with facts, not opinions. I've said before I'm not here for my ego...if that's how you want to read it, so be it.

G'day Stonecutter
Would not expect you to compromise your position, your a professional oven builder , and an asset to the forum .
I'm a mugg builder who will never forget the encouragement I got from the original plans .... It basically said.
If you have the choice between medium duty firebrick light duty firebrick or red commons .....build the oven anyway.
Regards dave

[Tscarborough]

Re: How bad did I screw up? Used the wrong mortar

An oven is an investment in time and capital. Proceed as such.

[Gulf]

Re: How bad did I screw up? Used the wrong mortar

It was, but i wasn't aiming it at anyone specifically. Thanks for that.

If you have contradicting advice what do I care?..back it up with facts, not opinions. I've said before I'm not here for my ego...if that's how you want to read it, so be it.

So mote it be

[stonecutter]

Re: How bad did I screw up? Used the wrong mortar

Kind of a sarcastic tone, but I get the point. Don't worry about any more contradicting advice from me. You da man .

It was, but i wasn't aiming it at anyone specifically. Thanks for that.

If you have contradicting advice what do I care?..back it up with facts, not opinions. I've said before I'm not here for my ego...if that's how you want to read it, so be it.

[Gulf]

Re: How bad did I screw up? Used the wrong mortar

Yeah, never mind. Fire it up, it'll be just wonderful.

Kind of a sarcastic tone, but I get the point. Don't worry about any more contradicting advice from me. You da man .

[cobblerdave]

Re: How bad did I screw up? Used the wrong mortar

G'day stonecutter
Problem is we haven't had peep out of the original poster.... Frustrating sometimes..... He could add to the collective knowledge....
Regards dave

[stonecutter]

Re: How bad did I screw up? Used the wrong mortar

Yeah, never mind. Fire it up, it'll be just wonderful.

[oasiscdm]

Re: How bad did I screw up? Used the wrong mortar

Fire it up.
Put food in it
Enjoy the eating

What will be , will be in the interim you get to taste the spoils

[Tscarborough]

Re: How bad did I screw up? Used the wrong mortar

I would at least burn it a couple of times first even if you do ultimately decide to tear it down.

Just a word on "best practice". As a professional in the industry, I have to give advice according to best practice at the very least. It is advice, not a demand or requirement, and anyone seeking advice on the internet should understand that they are getting exactly what they are paying for it. Caveat Emptor.