home brew mix

[waynespizzaworld]

I am wondering what kind of range for joint thickness you can get a way with when using the home brew mix of Portland, Sand, Lime and Fireclay.

Does one worry about using coarser sand in the mix for thicker mortar joints?

I have not used the home brew before but leaning in this direction for my next oven. Back to the mesh of sand, is there a recommended mesh to go with for gaps ranging from 1/16” to say one inch for some of the tapered joints in the dome?

Also when I am shopping for the lime, is there anything specific I should be asking for, or is all lime the same.

Thanks Wayne

[BarryKeith]

I would buy the refactory mortar.

[Cheesesteak]

Get Hydrated Lime - it should be widely available.

Regarding the mortar - any time I had a large gap (1/8" or more) I used brick shavings / wedges as fill between bricks - with the mortar.

Two reasons . . .

It's a great way to get rid of the hundreds of brick "shims" left from cutting bricks and it helps reduce the size of all the mortar joints.

Take a look at my oven in this post:

http://www.fornobravo.com/forum/8/ch...tml#post113880 (Cheesesteak's WFO build - Take Two.)

You can see the brick shims sticking out in the mortar joints. Let it dry a couple of days and tap them with a mason's hammer - they break off clean at the dome.

I've completed my dome, cured it and made pizzas and don't have any cracks at all.

[rodeair]

I just finished the dome for my 42 inch WFO. I never have used the store bought mortar, but really liked the homebrew. I used "hydrated lime" and "fine sand". Don't use the playground or all purpose sand. The nice thing about the homebrew was the ability of adding water as you go to keep the consistancy the way you like. For my dome I used about 50 lbs of portland, half a bag of lime, about 50 lbs of fireclay and about 150 lbs of sand.
Leigh

[Les]

Originally Posted by waynespizzaworld

or is all lime the same.

No, some is a white powder used in mortar mix and some are green that are used in Corona's.

I think I filled gaps around 5/8 inch wide. I would go w/ cheesesteak's recommendation of using the brick as shims. In hindsight, I would have done the same

[waynespizzaworld]

Leigh, so it sounds like its OK to rehydrate the mix as you go if it starts to dry out, which sounds good. This brings to mind another question I forgot to ask, how long is your work time with a mix? The store bought product I used on my last build had a very short work time and you were not supposed to rehydrate it so it meant making lots and lots of small batches.

And Les, its a good thing I know what a Corona is or may have been shopping for the green stuff........haha. Are you saying Les, that about 5/8th of an inch is about the max joint gap to be working with?

Thanks guys.

[rodeair]

Wayne, I usually mixed a batch which would be enough for about 10 bricks. That mix was about 6 cups sand and 2 cups others. That typically would last me for a couple of hours. I did rehydrate as needed, which was nice considering the 95 degree days. Also depending how long the bricks soak would determine how wet the mortar was. After the many courses, I was able to figure the wetness such that even the 75 degree course would stick after holding it for just a minute. I never needed props to hold the bricks as I went. Like I say, I love that homebrew stuff.
Leigh

[Tscarborough]

Best practice for portland cement mortars is ONE retempering. I would not exceed that.

[rodeair]

My practice was to mix the mortar fairly loose, keep what I wasn't using in a covered bucket in the shade, then mist the mortar in the tray with a spray bottle when needed. Hope that wasn't overdoing it, seemed to set up real well so far.
Leigh

[NYC]

Where can I see the exact ingredients and rations for this "home brew" mortar?