Drying it all out, when, what, how

[pistolpete]

I've read and seen lots of comments in the various posts about lighting fires to help dry your oven out but could not find one place to come for some info on it so thought I'd create one!

I'm building and oven at the minute (West Yorkshire Dry Stone Build) and hoping to get to the stage of finishing the dome this weekend.

I'm aware that a series of small fires to help drive out the water in all the mortar is required over a number of days.

So some questions:

* Once I finish building the dome itself, how long should I wait before I start my first fire?
* How many fires are "good enough"
* Do I put my insulation blanket on first?
* Do I get all my fires out the way before I put the final render on?
* How many fires?
* How long to burn them for?

Thanks in advance, just trying to schedule in my first pizza session so the wife can get excited

Pete

[turkey]

I soaked all my bricks and you can see the air inside bubble out when submerged but the force the water is exerting is tiny so if this was the cause then any mechanical force would have done the same. I can't see a brick in your pics to highlight but I would take a brand new brick and test. Worse case. Is as you say chipped corners but once you split it in two you will have another useable face (this is the face seen for all ny bricks)

It really helps cutting as its wet through so much better lubricated, wet bricks create clay when cut where dry bricks create smoke and dry cuts will shorten the life of the saw. I had wet bricks and a constant stream of water to cool the blade and clear the waste, the cuts where easy and the blade looks good as new.

I

[pistolpete]

Is this one in response to my other comment about my bricks chipping when soaked?

What about drying out fires?

Pete

[faz]

In my opinion, there is no exact science to the drying fires. If you follow the principle of the FB drying plans without getting too bogged down in maintaining the times/temperatures that they state you will be fine. Just start small and only slowly build up the size and duration of the fire.

Remember - plenty of patience is required - don't be tempted to chuck on a few more logs just to see what happens

[turkey]

Jul 20, 2012 19:50:28 GMT pistolpete said:

Is this one in response to my other comment about my bricks chipping when soaked?

What about drying out fires?

Pete

it was, replied using my phone and had been up 24hrs or so, not quiet sure how I replied to a previous thread here, that takes talent ;-)

re during fires slow slow slow but the reason is simple, steam is your enemy. In your come its 4.5 inches thick so even without insulation if you crank up the heat its possible to get hit enough for steam on the inside which will force its way out and can cause damage. Here I don't think the blanket effects it do much, but does slow air circulation over the outer face of the bricks so probably slows the process.

then the certificate/cement layer us very wet, but this is mire porous so I am not sure but think if your dome was dry but this was wet and you really cranked the heat in the dome you would be fine as the blanket insulation will regulate the heat getting to this and even for hit I think steam could easily escape without trauma.

if you want to use it soon I would aim to dry it as a brick structure and then insulate, and then deal with drying the wet insulation but believe the oven us useable then, once fully dry it will work better but should be massive crack safe.

small cracks are to be expected, I used builders sand in my homebrew instead of sharp so the outer joints tracked but was sound, had a think skim of mix later anyhow to be safe. This dried before putting on insulation so had it pretty hot with no I'll effects so far, outer insulation is still wet thanks to the weather, but hope this coming heat will finally dry it out.