Strength vs Simplicity

[das]

Re: Strength vs Simplicity

I contacted Asley a few weeks ago and they indicated that there were no distributors in this area that carry their MD brick. The freight cost would make them far to expensive for me. I can get the W-Greer product from several local suppliers and it is by far the cheapest.

I don't think I am concerned about the thermal properties as much as I am the durability of the product. It appears that the general concenus is that the WG low duty (the only fire brick product they make) is perfecty suitable for this project and it furhtermore would appear that the more expensive MT Savage medium duty product is simply not worth the extra expense.

This is one of those topics that gets a lot of thread space and a lot of opinion yet never gets fully answered. The FB plans appear to have changed to spec medium duty, making things that much more ambiguous with regard to the proper brick.

@Tscarborough

What is the problem with narrow face bricks? I would assume they may be more prone to spalling.

That's too bad about the Alsey bricks, I thought you may have better luck on the EC. The reason I am after Alsey bricks is they are supposed to be the most durable, which the W-G are supposed to be next best, so you should be fine. That is my second line of attack as well, though I think there also is something to the thermal properties of the higher density brick, especially with the wide variance of the readily available LD bricks sold at the local yards.


What Buckley points out about the lax industry standards makes it hard to determine what is good or not even from specs. Supposedly the Muddox, PC, and others don't meet even the new low level standards. Funny thing is Forno Bravo has some chart on Alumina content and they suggest 38% being medium duty, I called Muddox today, and well they use 38%, but were very clear they were low-duty, and supposedly they don't meet the ASTM standards.

I agree about the question never being answered. From searching here on FB it seems when the question comes up, a few jump in and say "I used such and such and my oven is fine, has a few cracks, but that is normal." Hence why I am defaulting to people that have been in the industry for years and have experience with most all the brands. I am building an oven on a stand and therefore plan on taking it with me if/when I move so I want to make it as durable as possible.

It would be interesting to know who makes the Forno Bravo bricks as it seems only a limited # of manufacturers make medium-duty, and also a more extensive reason behind their switch to medium-duty over light-duty.

[Les]

Re: Strength vs Simplicity

Orange County. Do you have a connection for Alsey?

Not for that make but there are a few builders in your area. Exceloven and Dino to name a couple. I'm sure they can lead you in the right direction. I thought you might be located in N. Cal. There is a great deal in Sacramento.

[Tscarborough]

Re: Strength vs Simplicity

Cracking, actually. There is a relationship between unit size and joint size. Standard specifications call for no units less than 25% of the normal uncut size.

[das]

Re: Strength vs Simplicity

das,

Whare are you located in Ca? It's a big state.

Orange County. Do you have a connection for Alsey?

[BeanAnimal]

Re: Strength vs Simplicity

I contacted Asley a few weeks ago and they indicated that there were no distributors in this area that carry their MD brick. The freight cost would make them far to expensive for me. I can get the W-Greer product from several local suppliers and it is by far the cheapest.

I don't think I am concerned about the thermal properties as much as I am the durability of the product. It appears that the general concenus is that the WG low duty (the only fire brick product they make) is perfecty suitable for this project and it furhtermore would appear that the more expensive MT Savage medium duty product is simply not worth the extra expense.

This is one of those topics that gets a lot of thread space and a lot of opinion yet never gets fully answered. The FB plans appear to have changed to spec medium duty, making things that much more ambiguous with regard to the proper brick.

@Tscarborough

What is the problem with narrow face bricks? I would assume they may be more prone to spalling.

[Les]

Re: Strength vs Simplicity

das,

Whare are you located in Ca? It's a big state.

[Tscarborough]

Re: Strength vs Simplicity

Also, while maintaining bond, do no use any brick that is less than 2" width on the face, and 3-4" is better.

[Tscarborough]

Re: Strength vs Simplicity

W-G light duty are fine even for commercial pizza oven use.

[das]

Re: Strength vs Simplicity

I believe the reason the Harbison Brick is so expensive is it's made in CA. HW is now part of a larger company that is local to you but the medium duty brick I believe is made in CA. I found out today the freight costs from plants across the nation and Canada adds anywhere from 25-200% to the brick cost.

I have called all around today, except ANH, for medium duty brick. I found the Alsey medium duty bricks I was after, but they were all re-brands They had traveled from IL, to WA or NorCal then to SoCal, by this time a $1.60 brick had turned into a $4.53 brick. I can buy their High-Duty indutrial bricks for $2.90. Either way it looks like freight shipping and fuel surcharges are the biggest factor on these bricks, considering they're 8lb a piece. All the brick made here in CA from Pacific and Muddox etc. are only $1.07-1.45.

Regarding Low vs. Medium Duty. On the surface the difference is temperature limit. But from the reading I did over the weekend the differences that are most relevant to us are the conductivity, and the dimensional stability from heat cycling. According to an Alan Scott book, medium duty have a heat conductivity of 60% and high duty is ~75%, therefore I figure a low duty is <50%. A. Scott said HD bricks for the hearth get too hot for bread baking and may burn the bottoms, and suggests MD, however suggests for strictly pizza a HD brick may be better suited. Jim Buckley of Rumford Fireplaces posted answers to the same question, High duty vs Low Duty firebrick on a Masonry Heater Association board. From his experience he stated that Alsey MD bricks are the best, and then seemed to suggest Whitacre-Greer or I-XL(which I hear is closing down) low-duty bricks as the next best. What he stated was that the ASTM specifications for fire-brick do no include any spec. for thermal expansion/stability which to him is the most important for longevity and reduced cracking/spalling. His suggestion for brick is based off personal experience and years of building fireplaces and fireboxes with all the major firebrick manufacturers on the market.

Considering the self-labor involved is worth much more, and suggestions from people with years of experience I plan to use either ALsey or H-W MD bricks if I can get them under $3.00, else I plan to use W-G low-duty (quasi MD bricks). I was bummed I couldn't find a full stocking Alsey distributor as they make a non-watersoluble mortar, castable refractory, fireclay, firebrick color stains, and large floor tiles as well as arch and key stones. Besides the ceramic insulation it would be a one stop shop with all the products designed to work together.

[dmun]

Re: Strength vs Simplicity

I don't think there is any advantage to medium duty firebricks at the temperatures we run. Don't spend the money, is my advice. Besides, if you are going to be doing a lot of cutting, you want easy to cut bricks.

[Les]

Re: Strength vs Simplicity

I recall the plans suggest medium duty. I know some have used light duty for their build and I haven't heard anything bad going on. If you were to fire it up everyday at crazy temps I would avoid them. If money is tight, I think you are safe.

[BeanAnimal]

Re: Strength vs Simplicity

Can anybody with knowledge jump in here? I need to get my bricks ordered so that I can get this puppy started.

[BeanAnimal]

Re: Strength vs Simplicity

So I have debated wether to start yet another thread or just defer to those who have helped here...

My only local source of fire brick is the Greer LIGHT DUTY product. Prices range from $1.25 to $1.75 each for 9 x 4.5 x 2.5

Harbison Walker quoted a whopping $2.59 each for MEDIUM DUTY brick, adding at least $350 to the cost of the oven. I can find no other lcoal medium duty bricks at supply yards or refractory distributors.

I did find a company (MT. Savage) in Maryland that manufactures MEDIUM DUTY bricks and will sell them for $1.17 each. So if I figure 300 brick to be safe, add $300 (just a guess) freight, plus the $8 pallet fee and a $35 partial pallet fee, I am looking at roughly $750, or $2.31 per brick. That is still fairly spendy but less than the local Harbison by $87!

So LIGHT DUTY $495 or MEDIUM DUTY $700

Is there ANY reason to go with the more expensive option? That is, is it AT ALL worth the extra money for the MEDIUM DUTY brick?

FWIW the tapers and arches only come in HIGH and SUPER duty products from any of the companies I have contacted... So that idea is out the wondow.

[BeanAnimal]

Re: Strength vs Simplicity

I had started to lay out each brick to ensure a perfect bond patterm, but realise that the real world and autocad will greatly differ due to mortar joints, etc. So the autocad plan is fairly generic with regard to brick widths for each ring and actual widths will need to be cut on the fly.

Autocad has been a very valuable tool for me with regard to laying out things like my arch, vent and dome. The dome will be 42" but only 19" high. I was able to simulate the offset indispinsable tool and how it would shape the dome, etc.

The software may take some of the "art" or "craft" out of the project, but I am not an artists or an old world craftsman by a long shot so I need all of the help I can get.

P.S.

The software is only a tool, the collective knowledge available here on this forum is invaluable. It is amazing to see the progression of ovens over the last several years!

[Les]

Re: Strength vs Simplicity

I have no plan to shape the bottoms to eliminate the horizontal vees.

Bean,

If you stay perfectly off bond - at the 13th course the brick is about 5/8 inch wide (you mentioned you laid this out in CAD so you see the issue). At that width, there would be no gap to speak off. Before I got to that point is where I realized the problem. Although I saw it coming, I had no appreciation of hard it was to hold onto the brick while cutting it. My advice - Make a fixture. The beauty of this forum has been evolution - go for it!