Fire brick problem. PLEASE HELP!!

[scubadan77]

Re: Fire brick problem. PLEASE HELP!!

I've just done my floor and are about to a temp to build the dome.I am using a small angle grinder with a diamond disc that cost me ?3 from the Chinese shop and it is cutting the fire bricks like butter!!! good luck with your build

[fornax hominus]

Re: Fire brick problem. PLEASE HELP!!

I made a drip onto the brick cut and it went way faster ..bur way messier .
Check out a hardware store with chinese imorts I buy 7'' blades on sale @ pricess auto

[Tscarborough]

Re: Fire brick problem. PLEASE HELP!!

That is why, for example, portland cement is packaged at 94#s +/-, and not 100#. 94# of cement = 1 CuFt.

It varies by manufacturer and area, for example here, Texas Lehigh Portland cement is 92.6#, Alamo Portland cement is 92.59 and Lehigh white portland is 94#.

[Tscarborough]

Re: Fire brick problem. PLEASE HELP!!

Ready-mix concrete plants weigh, but the weights they use are based on volumetric ratios. You should use volume for mixing mortar. That is how the BIA and ASTM both recommend and use in their specifications.

[huskerduck]

Re: Fire brick problem. PLEASE HELP!!

I used volume measure and how long it stays workable depends on the environment. I made a significant mix of the dry ingredients and then mixed batches of mortar small enough that I used them in 10 minutes or so before it went off.

Interesting on volume, we have been mixing our own concretes and mortars for a project and was talking to the people at Sakcrete about a 6 sack mix ....long story short there were a lot of 1:1:2:3 type scenarios on the ole interwebs that were talking "buckets" or "shovels" and the Sakcrete guy said it was weight and when we weighed our pails we used ( 2 gallon I think) a pail of Portland weighed 20.8 pounds and the concrete mix sand and aggregate weighed in at a whopping 29.2 pounds

Fortunately we always had 12 yards of mix delivered and 3 Pallets of Portland and kept track through the process and came out exact to 6 sacks per yard even after 36 yards, the strange thing we ran into was most certainly the water, we used a pitcher and it was amazing how the consistency would change drastically from one mixer load to the next, a cloud would cover the sun for 1 minute and you had soup, sun on the next mix and you had dry clumps, I'm guessing this mortar is the same scenario minus weight being the "volume"

[Greenman]

Re: Fire brick problem. PLEASE HELP!!

I used volume measure and how long it stays workable depends on the environment. I made a significant mix of the dry ingredients and then mixed batches of mortar small enough that I used them in 10 minutes or so before it went off.

[huskerduck]

Re: Fire brick problem. PLEASE HELP!!

You can make home brew mortar with Portland Cement, Hydrated Lime, Powdered Fireclay and fine sand 1:1:1:3.

It works fine, I used a little plasticiser in mine that just makes it a bit more pleasant to use.

Is the 1:1:1:3 by weight or container size and how long does the mix stay useable?

[Greenman]

Re: Fire brick problem. PLEASE HELP!!

You can make home brew mortar with Portland Cement, Hydrated Lime, Powdered Fireclay and fine sand 1:1:1:3.

It works fine, I used a little plasticiser in mine that just makes it a bit more pleasant to use.

[Nic Cox]

Re: Fire brick problem. PLEASE HELP!!

Thanks for all the advice so far it's been a massive help.

The next problem I can see Is that I will run out of heat proof mortar building my dome. the stuff i brought is very expensive and hard for me to get as the company is miles away and delivery seems to be expensive. Is there a way I can make my own mortar???

[tonybaker]

Re: Fire brick problem. PLEASE HELP!!

yes, the easiest way to cut bricks for the dome is to use a bolster chisel (wide blade) and a lump hammer (small sledge hammer). Put the brick on a soft but firm surface and give it a good whack all around the edge to be cut. Be sure to use safety glasses though.

I did not try to mortar the joins on the inside surface of the dome, just poked mortar in from the outside. I was conscious of the fact that I did not want mortar flaking off the inside and falling into the pizza! In the end I realised that perfection is not needed with the dome, you will tidy up the outside later with insulating material anyway.

I used perlite bricks which are easy to cut being softer, the oven heats up quickly and the heat reflects down onto two slabs of refractory material situated in the middle of the base.

We tend to use our oven most often for slow cooking tougher cuts of meat, or roasting chickens etc... It does not take much wood to get the heat up and I use old dry pallets mostly. As long as they are stamped HT you are ok to use them.

Good luck with your build and don't be too fussy!

[Novaslo]

Re: Fire brick problem. PLEASE HELP!!

Good luck Nick.
You have a long haul ahead and it will be totally worth every sweaty minute. I purchased a cheap wet saw- one that you can sell when you are done. But using the brick Bulster will make things easier. Lot of pounding though.

Wear eye protection!!
CYA

[Nic Cox]

Re: Fire brick problem. PLEASE HELP!!

Thanks for all the help it has been very useful, I also found that spraying water on the bricks as I cut them made life so much easier!!!

My oven floor is down and my soldier row up tomorrow I start on my arch, there is a high probability that I will ask for more help before the project is finished so keep an eye out for a desperate pizza enthusiast!!!

thanks again guys!!!

[cobblerdave]

Re: Fire brick problem. PLEASE HELP!!

G'day



Break the bricks in 1/2 with the brick bulster, the rough cut bit to the outside.
Saves heaps of time and energy

Regards dave

[SableSprings]

Re: Fire brick problem. PLEASE HELP!!

I have finished by oven floor now, and on Monday I shall start on the dome, this brings me to my next question; on most of the sites I've researched building my oven , people seem to cut their bricks in half to build the dome, is there a reason for this or can I use full size bricks??

In my opinion, the three reasons most people cut the bricks in half are;

1) Cost Saving - Why buy twice as many bricks as you need to do the job? Since a dome wall half a brick thick (4 1/2" or 10-12 mm) heats relatively quickly and provides plenty of stored heat after pizza for most home baking use (chicken, bread, cookies, etc.),

2) Time Saving - The full sized bricks will take much longer (and more wood) to heat and achieve thermal stability--not so important for pizza, but very important for the chicken, bread, cookies, etc.

3) Structure Specs - The increase in oven mass is obviously significant in several ways. If you go to full bricks, the time & cost increases in the build will dig into your pocketbook more deeply. There will be a need to be more conscious about the support structure of your foundation and oven platform...since there will be at least twice as much weight involved (depending on your increased mortar use covering the larger gaps that will form outside between the full bricks of the dome... ) and with a physically larger dome you will need quite a bit more insulation and stucco/finish to cover it ($). Since you will be burning a lot more wood, you'll also need to consider building a larger storage facility for it.

...if you're interested in making an oven intended for baking large amounts of bread daily--like going commercial--then the increased heat storage mass of full bricks (and a barrel shape for ease in loading/unloading) will be an advantage. If you aim for some pizza a couple times a week or for casual home baking use like most of us, then the half brick makes for a much more efficient system (less wood, less time, more pizza/bread sooner)

[Tscarborough]

Re: Fire brick problem. PLEASE HELP!!

You may need something harder than a brick. A chunk of old concrete works well.