Wetting the Bricks

[Evets]

I have a couple questions concerning my oven build. Firstly, I know that prior to setting brick with mortar, the bricks should be wet. Question is, HOW wet? Is a quick dip good enough? Or maybe a 30 second soak? Or should they be totally saturated?
Secondly, as far as laying the bricks for the cooking floor; can the sand/clay mix be left dry, or must it be mixed with water?
I appreciate any wisdom you all may care to share.

Steve

[Ken524]

Re: Wetting the Bricks

Steve,

When you start laying bricks, drop several in a big bucket of water and let them soak until they stop bubbling. Usually 4 or 5 minutes will do it. The idea is to saturate the bricks with water so they don't suck the moisture out of the mortar before it cures.

Lay your floor bricks on dry sand/clay.

Good luck with your build!

[Brent Woo]

Re: Wetting the Bricks

I have a couple questions concerning my oven build. Firstly, I know that prior to setting brick with mortar, the bricks should be wet. Question is, HOW wet? Is a quick dip good enough? Or maybe a 30 second soak? Or should they be totally saturated?
Secondly, as far as laying the bricks for the cooking floor; can the sand/clay mix be left dry, or must it be mixed with water?
I appreciate any wisdom you all may care to share.

Steve

Personally, I would give the bricks at least a 30 second soak. I go with soaking till the bubbles stop. In keep a 5 gallon bucket nearby, grab a couple and stick them in as I lay the mortar on the bricks I just took out. The bucket also comes in handy in removing any extra mortar off your hands or tools.

Brent

[Evets]

Re: Wetting the Bricks

Great! Thanks! I'm glad you said DRY sand/clay is ok, because that's what I already did!

[Tscarborough]

Re: Wetting the Bricks

Surface saturated dry is what you want. Do not soak the brick, but dip them.

[leckig]

Re: Wetting the Bricks

looks like this is a very controversial topic. Saturated bricks slide and need support, seems like fairly dry bricks stick much easier. Some people say dry bricks will suck too much water from the mortar and render it weak, some people say the opposite is true.

The truth is out there...

[Tscarborough]

Re: Wetting the Bricks

It is not controversial to those in the masonry industry. Here is the relevant section in the standard specification:

A. Wetting Brick:
1. Wet brick with absorption rates in excess of 30 g./30 sq. in./min. (30 g./194 cm2/min.) determined by ASTM C 67, so that rate of absorption when laid does not exceed this amount.

2. Recommended procedure to insure that brick are nearly saturated, surface dry when laid is to place a hose on the pile of brick until the water runs from the pile. This should be done one day before brick are to be used. In extremely warm weather, place hose on pile several hours before brick are to be used.



Firebrick are on the high end of the absorption scale, and in the context of laying brick at home, i.e. slowly, it is not practical to use the described method. The best way to do it is to briefly dip the brick into a bucket of water or mist it prior to laying it.

[Derkp]

Re: Wetting the Bricks

I agree with tscarborough, wet the bricks by dipping of spraying them. My bricks had years of grime on them and I power washed most of them as I installed them. If the bricks were too wet the mortar did not stick well. After I washed them I let them set until I could climb up and set them, the surface was not soaked but moist the mortar worked great. They seemed to dry out very quickly in direct sun, 85 degrees plus.

Derk

[leckig]

Re: Wetting the Bricks

maybe the ebook should be updated with this info. Thanks so much for the detailed explanation! Some of my bricks soaked for days.. now I am worried a bit.

[Tscarborough]

Re: Wetting the Bricks

No worries, just put them in the sun. Since they have a high rate of absorption they also have a high rate of moisture loss.

[Derkp]

Re: Wetting the Bricks

I agree with tscarborough, they will dry out quick in the sun, I just kept the mortar moist with a spray bottle.

I just pulled my forms and I see a fair amount of gaps where there is not enough mortar on the inside joint, or none in places. Can I repoint those joints or will the heat just pop them out in the curing/cooking process?

Can I use regular mortar for the locking in layer on the outside of the arch or does it need to be refractory? I only have the ingredients for homebrew left.

Thanks,

Derk

[Tscarborough]

Re: Wetting the Bricks

You can fill them, and can use regular mortar outside, but if you have the stuff to make homebrew I would.

[Derkp]

Re: Wetting the Bricks

I have the ingredients for the homebrew, I will use it for both the inside and outside. I am going to sieve some playground sand for a little finer mortar for the inside gaps. I have industrial quartz from HD that I can use for the outside mixture.

Thanks

[jmhepworth]

Re: Wetting the Bricks

I hate to disagree with someone who quotes an actual standard, but my experience with Heatstop was that if the firebrick was just moist the joint failed more often than if the brick was soaked. The Heatstop rep I talked with on the phone told me to make sure the brick was wet. He also told me to use cold water. My experience in soaking the brick until the bubbles stopped worked.

[Tscarborough]

Re: Wetting the Bricks

The great thing about standards and specifications is that they allow for wriggle room. Conditions and materials differ, and the bottom line is that what works on the jobsite is what should be used. If you are in the Utah desert at 100 degrees with a wind, what works for me in Austin with 80 degrees and 30% humidity will not work for you, nor will 40 degrees and 100% humidity.

The key concept is that the laid brick should grab quickly and not require more than a moment or 2 to support itself.