Home Brew

[Islandguy]

I have built 3 ovens over 3 years using the Home brew recipe as a castable over a sand form with a wire form cage 4" thick. That first oven is trailer mounted and has spent most of its life outside year round in the pacific northwest. It cracked during curing before it was ever fired and still has the same cracks with very little change since it was made and has been towed a couple thousand miles. The Home Brew formula is incredibly tough remember final strength is only achieved after firing the oven the home brew is not just a cement or mortar it is a fired clay it does not achieve full strength until you cook it out fully.

the original oven even after being soaked in the rain for weeks just takes a extra hour or bit more to steam out and come to heat. My experience does not lead me to think sealing is required.

1-1-1-3 is a Solid Mix.

[Gulf]

Another way to say it would be 1:1:6 of portland:lime:sand, yes?

That is correct for type-N mortar.

does my fire mortar withstand the elements just like the regular Type-N masonry cement?

I don't have enough years of first hand experience with hombrew to answer that for sure. There are a lot of builds on this site that has the entry brick and it's home brew exposed. I haven't heard of any problems with the mortar not holding up. It is just that the home brew recipe is designed primarily as a refractory mortar. But, unless your oven is under some type of cover, you may want to think about a clear masonry sealer or an additive. That advice goes for any mortar recipe that you use for the exterior.

[llamabucket]

Not exactly.

Type-N masonry cement is 1 part portland and 1 part hydrated lime. Add 1 part of that mix (after mixing the two) to 3 parts sand and you have Type-N masonry cement. So, the formula from scratch for type-N mortar is 1/2 part portland, 1/2 part hydrated lime and 3 parts sand.

Home brew refractory mortar is 1 part portland, 1 part hydrated lime, 1 part fireclay, and 3 parts sand.

Fantastic thank you!!! Another way to say it would be 1:1:6 of portland:lime:sand, yes?

Also, does my fire mortar withstand the elements just like the regular Type-N masonry cement? As I'll have areas where both types of mortar will be exposed. I assume it will but just checking

[Gulf]

Not exactly.

Type-N masonry cement is 1 part portland and 1 part hydrated lime. Add 1 part of that mix (after mixing the two) to 3 parts sand and you have Type-N masonry cement. So, the formula from scratch for type-N mortar is 1/2 part portland, 1/2 part hydrated lime and 3 parts sand.

Home brew refractory mortar is 1 part portland, 1 part hydrated lime, 1 part fireclay, and 3 parts sand.

[llamabucket]

Yes! It will be separated from the fire bricks and exposed to the elements. So with this traditional mortar recipe, the only difference is just not adding fire clay?

I'm reading it may not be workable and to add something to it?

If it is for another layer of brick to add to the thermal layer, by all means. However, If that layer of brick is separated from the thermal layer by insulation and is subject to the elements, you may want to go with a more traditional mortar. The old formula for Type N masonry cement is 1 part hydrated lime and 1 part portland cement. Add 1 part of that mix to 3 parts sand and you have Type-N mortar. That formula works very well .

[Gulf]

If it is for another layer of brick to add to the thermal layer, by all means. However, If that layer of brick is separated from the thermal layer by insulation and is subject to the elements, you may want to go with a more traditional mortar. The old formula for Type N masonry cement is 1 part hydrated lime and 1 part portland cement. Add 1 part of that mix to 3 parts sand and you have Type-N mortar. That formula works very well .

[llamabucket]

UPDATE! So everything worked perfectly! The fire mortar came out amazing and our firebricks are in place. Thank you for your help!

One other question, we have a lot of the fire mortar ingredients left. We'll be covering the whole oven with an arch of red house bricks and I'm wondering if we can use the same recipe we used for the refractory mortar on these as well? I see recipes for regular mortar call for portland cement, sand, hydrated lime anyway...and some even suggest adding fireclay for workability so I'm thinking why not?

[Gulf]

....................."To use as lime wash.................."

"Lime wash" is what we called "white wash". The main ingredient in white wash is hydrated lime. I think that it will work just fine .

[llamabucket]

Hey! Here's an update! This is what it says on the back of the bag. Does this confirm it's good for mortar? I'm concerned as it says it can be used for gardening since I hear that lime is either, or. Not for both building and gardening?

"To use as lime wash, mix 6kg with water to a creamy consistency and allow to stand 10 minutes before using. A small capful of dissolved salt added to this mixture will improve adhesion considerably. For sweetening lawn and garden soil, apply a week before or after fertilizer has been added. The recommended dosage is 24 sq. m per 6kg bag"

I think that the hydrated lime that you have found will be just fine. That is what the recipe calls for. I could not even get that locally. I think that the "Type S" hydrated lime is preferred ( for workability) , but not a critical indgredient as long as you have hydrated lime. Maybe Tscarborough or others will advise.

[llamabucket]

Oh that's wonderful! I'm racking my brain trying to figure out if what I bought is type-n? Type-s? What the difference it would make for the Homebrew recipe?

I was also suggested Dolomite by a pottery shop owner but I disregarded it as no one here seems to use this. After some googling however, I've discovered there's Dolomitic Type-S Hydrated Lime too??? I'm wondering if that's what he was referring to?

Either way, if the hydrated lime I bought will work well then that would be perfect!

I'd love to hear what others think too!

Thank you

I think that the hydrated lime that you have found will be just fine. That is what the recipe calls for. I could not even get that locally. I think that the "Type S" hydrated lime is preferred ( for workability) , but not a critical indgredient as long as you have hydrated lime. Maybe Guest or others will advise.

[Gulf]

I think that the hydrated lime that you have found will be just fine. That is what the recipe calls for. I could not even get that locally. I think that the "Type S" hydrated lime is preferred ( for workability) , but not a critical indgredient as long as you have hydrated lime. Maybe Tscarborough or others will advise.

[llamabucket]

Hey all! I'm having a very hard time finding hydrated lime, but I finally picked this up after days of searching: http://www.rona.ca/en/hydrated-lime
It doesn't say "Type S" which has me concerned. Is this the stuff to use?

[Tscarborough]

Re: Home Brew

It is it's thermal stability.

[v12spirit]

Re: Home Brew

I'm tempted to use crushed basalt instead of sand in my homebrew as it was the material used in ovens built by old timers grannies. Moreover. I found Wiley's steel oven clad with cement fondue and crushed basalt. Is it the structural strength what makes this material used or its heat retention?

[v12spirit]

Re: Home Brew

Thanks Tom. Should have done that long time ago.