Home Brew

[v12spirit]

Re: Home Brew

G'day
Homebrew is softer and can fill larger gapes. Its a mortar designed to fill the gapes between brick units, its a gasket rather than a super hard "glue"
I think you are looking for your samples to be super hard and cured fully but that's not what homebrew is. Its a mortar pure and simple
Regards Dave

Those experiments were tempting me to order cement fondue and clad with it 50.50 with sand. Do you mean homebrew will do the job better?
By the way, does a bag of cement fondue has an expiration date as the bags of Portland cement? I'm just afraid I will end up buying expired fondue while I could keep experimenting with fresh homebrew..

[cobblerdave]

Re: Home Brew

G'day
Of course these samples are not entirely cured. The Portland cement may be set but not cured that will take a month to get near to its ultimate strength. As for the lime it can be a longer period for it to combine with CO2 it will the heat from an oven will accelerate this otherwise it can be years.
Yes Ciment fondue makes a fast setting mortar its completely cured in the first 24 hrs. Its heat resistant to twice the temps of a WFO. But it cant be used to span a gape of more than 5 mm its too hard and it will crack. Homebrew is softer and can fill larger gapes. Its a mortar designed to fill the gapes between brick units, its a gasket rather than a super hard "glue"
I think you are looking for your samples to be super hard and cured fully but that's not what homebrew is. Its a mortar pure and simple
Regards Dave

[v12spirit]

Re: Home Brew

That is exactly what happened with me the first day. Eager to hear more from your progress.

[DavidApp]

Re: Home Brew

Having made a small sample of home brew I cast a piece about 8' diameter by 1 1/2 " thick and left it to set overnight. About 12 hours later I removed the casting from the tub. It had set but the edge was crumbly. After 24 hours I can break pieces off the edge and they crumble. I will keep checking it at 24 hour intervals.
I made up another small batch, wet 2 brick segments as I would when I was laying the dome. Then mortared them together with the home brew mix. The mortar grabbed quickly. I will check the bond in the morning.

I know how strong Heat Stop 50 is because I tried to remove a brick that had slipped a fraction. I could not pry it out and hitting it did not budge it. I decided to leave it as it seemed it would take a lot of effort to remove it.

David

[v12spirit]

Re: Home Brew

Thanks Saovicente, DavidApp.
I appreciate your details and trial to make a sample. In the first attempt, I let the brew dry in the weather. Ended up quite crumbly. The second was yesterday. I made 1.5 Liters brew and covered it immediately with plastic and left it outside 3-15 C.

Saovicente. Looks like I have to do it again using your sophisticated recipe. What did you mean by 6 to 9 mil of plastic. I may even warm the steel liner to keep the brew warm.

DavidApp. The Portland cement is fresh. I just used it fo other applications and it hardened pretty well. Eager to hear about the results of your experiment.

[DavidApp]

Re: Home Brew

Just a thought.
How fresh is your Portland cement? I have been using home brew to cover the outside od my dome. Heat Stop 50 is too expensive to use for that.
I did not notice that it was crumbly and after 10 days it is defiantly very hard.

I will make up a small batch and let you know how it is after 24 hours.
I understand that Portland cement powder will lose something as it ages. Last year I made some Vcrete with an old bag of Portland cement and it a long time to fully set.

David

[Saovicente]

Re: Home Brew

Yes. Exposure to heat will harden the brew. But was your brew initially crumbly? I mean after a week?

It will strengthen the mix but one must make sure it is a slow, steady process, otherwise there will be a multitude of cracks, especially if the oven if of a singular form. For my mix the compressive strength has been impressive.

To answer your question: No! it did not crumble at all. I have had a few years experience playing with concrete mixes and one of a multitude of factors to good results is heat retention. Simply make your mix (Make sure it is not a slurry mix, nor does it need to be on the dry side) break up your form into four or more pieces (I made 6) Wait a few hours for the form to harden a bit (pending surrounding temperature) cover the lovely beauty with 6 to 9 mil of plastic and a blanket or two (again depending on the surrounding temperature - I made my beauty around the end of march) and let it sit covered for at least 1 to 2 weeks or more. If you need to - put an oil heater under the table to keep the mix hot, especially during the first week. When you touch the mix, it should feel hot to very warm and there should beads of sweat dripping of the plastic.


As an old idiom goes: more than you bargain for hopefully it helps answer your question.

[v12spirit]

Re: Home Brew

I made a barrel oven with the 3.1.1.1 recipe with the add-on of stainless "melt extract" needles and poly fibers to great success. The oven has gotten stronger from the past six or so months of usage. I last used it on New Years day (temperature was in the low teens) and it performed flawlessly.

Yes. Exposure to heat will harden the brew. But was your brew initially crumbly? I mean after a week?

[Saovicente]

Re: Home Brew

I made a barrel oven with the 3.1.1.1 recipe with the add-on of stainless "melt extract" needles and poly fibers to great success. The oven has gotten stronger from the past six or so months of usage. I last used it on New Years day (temperature was in the low teens) and it performed flawlessly.

[david s]

Re: Home Brew

Try making a couple of litres of the brew and cover it for a week so it doesn't dry out. Consistency should be "ball up" ie take a handful and make it into a ball. Throw it about a foot into the air, it should not fall apart. Too much or too little water will weaken it.

[v12spirit]

Re: Home Brew

I used hydrated lime, Portland cement, clay, and sand in the 1:1:1:3 ratio. The 300 ml brew sample was left 3+ days.. Still crumbly; I could even break it by hands! Does the small volume of the sample weakens the brew that much?

[david s]

Re: Home Brew

Hard to say from your description, but I use silica sand which tends to have more angular grains which grip better than rounded ones, but any sand should do.

[v12spirit]

Re: Home Brew

You can crush firebrick, I have done quite a lot, but it is really hard work. Do not try crushing insulating firebricks because although they're much easier to crush, You will be introducing air into your mixture.You have to use dense firebricks.You could use crushed basalt but it won't make the mix any denser than using sand.Sand will make the most workable mix and allow you to apply it with the least amount of air in the brew so it would be the best option I should think.

I have three types of sand; two come with pearl-like fine grains one of them is sliver white and the second is reddish, the third is almost like a yellow powder. The first two are more expensive but available as leftovers from my original oven build. Are there any advantages among each over the other?

[david s]

Re: Home Brew

You can crush firebrick, I have done quite a lot, but it is really hard work. Do not try crushing insulating firebricks because although they're much easier to crush, You will be introducing air into your mixture.You have to use dense firebricks.You could use crushed basalt but it won't make the mix any denser than using sand.Sand will make the most workable mix and allow you to apply it with the least amount of air in the brew so it would be the best option I should think.

[v12spirit]

Re: Home Brew

Thanks mates for the helpful inputs. I'm happy that the "claimed" hydrated lime will do the job. I just hope I'm sold the right material.
If I were using my homebrew in making castable refractory (In my case I'm cladding a steel dome oven) is it better to substitute sand with crushed basalt? I found some posts talking about using crushed basalt in castable refractories.. and can I use crushed fire bricks instead or a combination of both? Feels like both have some thermal properties that sand does not have so that I'm tempted to incorporate one or both in my homebrew.