Share your crack stories

[oasiscdm]

Re: Share your crack stories

Gudday
Think again .....I have gapes between my bricks which at one stage I didn't like so ..... I ignored the one set of advice to ignore it. I liked the one that said crawl in with a piping bag of mortar . I did manage to crawl in to my 12x 20 entrance to discover ones torso blocks both light and air. Scared the hell out of me.

Regards dave

Hi Dave

i resemble those remarks ......as an aside. I once renovated a bathroom and my plumber mate wanted me to crawl under house to put in a support under the shower base [hate that]. I panicked as there wasn't a lot of room he came under like a bloody rabbit and i got out, well tried too.

The access to under the house was only 4 bricks high. Got in easily on the way out i got half way [head outside, thank god] but got stuck and panicked. layed there for nearly 30 minutes to try to calm down before i could wriggle out. when you panick your chest expands.

It was the biggest my chest has ever been

So i understand how you may have felt squeezing into that small space, no light [or air] i had light and air but still scared the shit out of me.. as i couldn't move the more i panicked the more my chest expanded.

the funny thing was my mate couldn't get out either........ as there was this fat man blocking his exit. LOL

[cobblerdave]

Re: Share your crack stories

Gudday
I built with a soldier course cause it was in the plans....but now I agree with you david s and most will ......but it's still in the plans

Regards dave

[david s]

Re: Share your crack stories

Thanks Dave.

I attached a photo of my situation. You can only see cracks from the inside of the oven. I fired it up last night. I don't think they got any bigger. At some point, do I fill with mortar or just let it be a trademark of my WFO?

I have never really understood why a soldier course is recommended. Usually cracks in the dome begin at the base, which is the weak point of the dome and want to travel vertically. By doing a soldier course you are merely encouraging this to occur. The only advantage that I can see is that you get a little extra height at the perimeter of the dome. That could be achieved by laying two normal courses without leaning them in on the dome radius profile and laying them in bond. Is the soldier course recommended in the Pompeii plans and if so can anyone support it's advantages?

[cobblerdave]

Re: Share your crack stories

Gudday
Think again .....I have gapes between my bricks which at one stage I didn't like so ..... I ignored the one set of advice to ignore it. I liked the one that said crawl in with a piping bag of mortar . I did manage to crawl in to my 12x 20 entrance to discover ones torso blocks both light and air. Scared the hell out of me.
But I"m stubborn as well as stupid. So I ventured back with lamp and extraction (shop vac ). Filled a small space above the entrance and to one side and retreated to see if it would work.
The mortar fell out,I stopped worrying about , and set about cooking and eating and enjoying my oven

Regards dave

[CoyoteVB]

Re: Share your crack stories

Thanks Dave.

I attached a photo of my situation. You can only see cracks from the inside of the oven. I fired it up last night. I don't think they got any bigger. At some point, do I fill with mortar or just let it be a trademark of my WFO?

[cobblerdave]

Re: Share your crack stories

Gudday
Not having "best practice" doesn't mean your oven will not work.
Use your oven and see what happens first. I recon it will still works cracks or no cracks. If they upset you on the outside of the dome enclose the whole dome and fill with pealite. Out of sit out of mind.

Regards dave

[CoyoteVB]

Re: Share your crack stories

I think I will just fire it and bake another pizza. If I have a complete dome failure it will probably be speculator. I will post a picture of my dilemma shortly.

[mikku]

Re: Share your crack stories

or a size bigger pants, suspenders or a belt!

[stonecutter]

Re: Share your crack stories

Wouldn't "moon beam", "high beam", "low beam", "running lights", or "harry" be better? At least it would be more descriptive of "phases of the moon?"

No.


He never showed his whole posterior, which nullified any term given to full exposure, and as for the extent of hair covering said posterior, I never cared to look longer than a millisecond.

The nickname was not only a name....it was a suggestion. Like this, "You need some spackle, Spackle."

In his case, the name was perfect. And it never ceased to produce belly laughs from everyone...except him of coarse. You would think he would buy longer tailed shirts...oh well.

[mikku]

Re: Share your crack stories

This reminded me of a guy I worked around a while back. Same problem and no matter how hard you tried not to see...you did.

We called him spackle. More of a sheetrocker term but you get the idea.

Wouldn't "moon beam", "high beam", "low beam", "running lights", or "harry" be better? At least it would be more descriptive of "phases of the moon?"

Yuck! Don't get me going, have touble sleeping as it is!

[mikku]

Re: Share your crack stories

I don't know if that is the cause, probably more likely the firing thing--your floor bricks are still movable right? Probably a combination of everything! The pros would know, just have to get their attention!

Now you need to work on the fix... As brickie and stonecutter suggest, maybe you need to work 20 or 30 years perfecting the technique of flicking mortar with a great deal of accuracy. Then you can do your repairs successfully by filling the cracks when they unexpectantly appear--without even having to get inside the oven! But try to keep your eyes peeled for the occasional "full moon". That is the most difficult to get out of your mind!

All joking aside, keep asking the pros... or maybe better yet, search the archives--you never know what is there until you look deeper. That way, you keep the "wolf" at bay! So it can answer more important questions???

[CoyoteVB]

Re: Share your crack stories

Mikku-

I think you may have identified the source of my mysterious crack. I attached the first row with a thin layer of mortar. I also mortared the joints and back using a heavy coat of Mortar.

Brian

[stonecutter]

Re: Share your crack stories

I used to work in a bricklaying gang where one guy used to always have his crack showing as he bent forwards, every time you turned around you got an eye full, he thought it was hilarious until I started flicking mortar at his crack.

He never did cover it up though.
I nicknamed him Crackers.

This reminded me of a guy I worked around a while back. Same problem and no matter how hard you tried not to see...you did.

We called him spackle. More of a sheetrocker term but you get the idea.

[david s]

Re: Share your crack stories

Almost all ovens and kilns have some cracks. Wood fired ovens are heated way too fast for the refractory to cope with the expansion that takes place. Around 300 C per hour. The industry standard for kilns is 100 C per hour. Firing with wood is way harder to control than oil, gas or electricity. The crown of the dome and the centre of the floor are heating up way faster than the outer perimeter. I think that is why the cracking starts down there. Also it is the weakest part of the dome.if you want to be kind to your refractory then take it slow, but nobody really wants to do that. We tend to try to get it to temp as fast as possible,a hence we have some cracks.

[mikku]

Re: Share your crack stories

It does not make any sense.
Your dome is built on top of the floor--
If you initially put anything down, even a sheet of newspaper that would prevent the brick dome from sticking to the hearth firebrick; and the hearth firebrick not mortared down in anyway--except for a possible sand and fireclay slurry...

Everything should be able to move freely with expansion.

Further, you have several layers of ceramic blanket insulating the dome--so no direct contact to your outer render.. Here nothing to restrict movement...

Possibly ceramic fiber is not what it is cracked up to be! Maybe it allows masonry to heat up in excess too quickly? Where perlite vermiculite moderate the heat up? But that discussion does not help your situation!

The real guys in the know who could answer these questions need to help here.
Right now simple reasoning from another newbie isn't producing any acceptable answers.. Except..possible normal expansion and drying, cracks that do not show up until extended usage and not to worry about! But just a guess.. mine isn't even fired once and I'm doing everything against better advice!

Keep asking--the pros will surely step in to assist!