36" build in Tallahassee - AKA Bruce's Folly

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Bruce,
The fb board is still a concern of mine I'm trusting I made the right decision. hope it don't come back to bite me. Since I decide to move on in my build, no one has posted anything further. Makes me wonder. I hope I have'nt affended anyone with my kidding around. If I did, my appologies to all. I value everyones opinion and need all the help I can get. Feel free to post on my thread.

Actually, I was a bit worried about having a difference in compression because one quadrant of the floor insulation is biosoluble and the rest are HW CF. the biosoluble has a very different texture compared to the CF and is much more fragile. I purchased the biosoluble board from skyline and there was no spec sheet on their site. I found another site that carried both types of board and compared the specs. Both boards had the same rating of less then 10% at 4,000 lbs per sq. inch. I think us 1st timers worry too much. One of the reasons I decided to take a shot at this is that it seems that as long a the dome doesn't collapse, there is enough insulation, and you get the water out (and keep it out) the resulting oven is at least functional. For example, with all our worry about the tapering bricks and small gaps, it appears that builds simply using 1/2 bricks and mortar work just fine.

I see you have really thought out the oven support. I think it will be plenty. I questioned it also till I seen the pictures underneath. I think it is rock solid with all blocks and angle underneath.

Don't know if you looked at my first thread:

http://www.fornobravo.com/forum/f6/p...rth-18862.html

I was trying to come up with an approach to the stand that I could do myself while working from my wheelchair. My first approach using some metal shelves spanning the cinder block was abandoned following a number of helpful comments. An alternative and cost effective idea was offered:

Bruce,

I can't imagine building anything on a $67 dollar shelf from Costco, heavens forbid, anything safe. $67 might get you enough blocks for your support?

So I pretty much just added cinderblock to pretty much fill in the interior of the stand and used extra angle to support the board over the storage area. I used the surface bonding because I read that it was rated to make mortar less structural walls when the interior and exterior surfaces of the block were coated. I am very confident in the resulting stand, at least here in Florida where frost and seismic activity are not a worry. Sink holes on the other hand...

Thanks again for checking in and giving the:

Bruce,

I can't imagine building anything on a $67 dollar shelf from Costco, heavens forbid, anything safe. $67 might get you enough blocks for your support?

Bruce

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Kbartman,
By the way, the last few days I started paying attention to the break down of active uses. Just looking at the number of users viewing threads at any one time I was surprised that so few were commenting. But then I saw that very few were members of the site. For example, right now there are 6 members and 146 guests on the site. So now I think I am more surprised at how many comments we are getting.

[kbartman]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Bruce,
No I have'nt read your first thread I will though. I got to gets some sleep to day I'm working nights. Funny you should mention sink holes. How about giving me a warm fat fuzzy on this one. While cutting the pool deck floor for the fondation I discover a viod beneath the concrete slab about 8" X 2' At the time I contributed to improper fill around the pool when install 1970 I figure. I filled it in and moved on. Then yesterday I notice a few old step cracks in the wall surrounding the pool. Is my build doomed for failure from bad insulation or a sink hole........ I sure need some warm fat fuzzies. Off to bed wish me sweet dreams. ...LOL

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Actually, I'd be more worried about that meteor...

Sweet dreams and fat warm fuzzy to ya.

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Actually, I was a bit worried about having a difference in compression because one quadrant of the floor insulation is biosoluble and the rest are HW CF. the biosoluble has a very different texture compared to the CF and is much more fragile. I purchased the biosoluble board from skyline and there was no spec sheet on their site. I found another site that carried both types of board and compared the specs. Both boards had the same rating of less then 10% at 4,000 lbs per sq. inch.
Bruce

Looks like I posted too soon regarding the biosoluble board. I emailed Skyline and within a few hours they replied that the compressive strength of the ceramic fiber board is 0.3MPa. This compares to .5 MPa of their comparable CF board. I am going to start trimming floor brick and deal with this issue once that is done. I think I have enough scape pieces of the CF board to replace the biosoluble. Glad I caught this now and not when well into building the dome.

[UtahBeehiver]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Bruce,

I accidently responded to you on Kb thread.

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Bruce,

When you get done trimming the Ca Sil to where you want, take your leftover mortar as you lay your bricks and render the sides of the Ca Sil board. The mortar will keep the Ca Sil from getting damaged, broken, dented while you do your dome.

Sounds like good advice. If the material stays in place I will do this.

I tried calculating the lbs per sq. inch placed on the board below the perimeter brick. I expected the result to be low, but not as low as I calculated and this was with higher then expected dome weigh. In addition at least some of the load will be transferred to the remaining board. I hope someone checks my math.

I used the following formula and values:
Weight of dome (estimated to be 2000 lbs)/Area of space between inner and outer perimeter of bricks
The first value was ((pi x 22 squared) - (pi x 18 squared))=503 sq inches
So 2000/503=4 lbs per sq inch.

Really doesn't sound like much. According to a conversion site on the web, .3 is about 44 psi and .5 is about 73 psi.

I found this definition of MPa in connection with material compression strength:

MPa is one million pascals.

A pascal, Pa, is one newton per square meter (N/m^2)

So a MPa is one million newtons per square meter.

"In material strength, it represents how much stress (force per cross sectional area) that a material can withstand without breaking/rupturing/stretching or whatever other criteria you use for failure."
What is MPa stand for when it comes to material strength? - Yahoo! Answers

Anyone comment who has experience with this issue. Thanks, Bruce

[UtahBeehiver]

Re: 36" build in Tallahassee - AKA Bruce's Folly

It should stay just fine here is a pic of mine. I learned this a little late in my build.

[cobblerdave]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Gudday Bruce
Don't loose that Bio-sol ...... It will come in handy for insulation in your future door.
Regards dave

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Sounds like good advice. If the material stays in place I will do this.

It should stay just fine here is a pic of mine. I learned this a little late in my build.

Thanks for the pic, looks really well done. However, I miscommunicated on that part of my post. At the time I was questioning whether or not the biosoluble board needed to be replaced. Based on information to date, it looks like it can remain. Hope to get some more expert options on this. Bruce

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Gudday Bruce
Don't loose that Bio-sol ...... It will come in handy for insulation in your future door.
Regards dave

That's the plan, though still haven't figured out how to fabricate the door so that now that it involves an arch. May have to take a pause this weekend and work it out. Bruce

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Well in addition to all the questions and dithering over the biosoluble board, I actually made some real progress on the floor. I pretty much wore out the blade doing all the cuts. The darker bricks are still wet from going through the saw. Feels good to manage this much. Bruce

[kbartman]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Bruce,
Nice floor moving right along. Consider the sanding I did on my floor I’m really pleased with how my turned out.

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Bruce,
Nice floor moving right along. Consider the sanding I did on my floor I?m really pleased with how my turned out.

Agree that your floor looks very good, could you describe your technique (e.g., type of sander used ect...), either on this thread or on yours? Thanks, Bruce

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

I tried calculating the lbs per sq. inch placed on the board below the perimeter brick. I expected the result to be low, but not as low as I calculated and this was with higher then expected dome weigh. In addition at least some of the load will be transferred to the remaining board. I hope someone checks my math.

I used the following formula and values:
Weight of dome (estimated to be 2000 lbs)/Area of space between inner and outer perimeter of bricks
The first value was ((pi x 22 squared) - (pi x 18 squared))=503 sq inches
So 2000/503=4 lbs per sq inch.

I'm still hoping someone will check my math on this, still seems very low.