domes

[timburly]

So the minions are requesting a dome for the 2007 burn. Thought I would get started into the plans supplies ect. So I'm looking for a bulk/wholesaler of 1 inch EMT conduit. Any dome builders out there have some good leads?

[unjonharley]

Don't know about the emt. But Harbor Freight has the press you will need. You can always sell it when you done. $109.99

[spectabillis]

just do the igloo thing and try it with ice.

[EspressoDude]

So the minions are requesting a dome for the 2007 burn. Thought I would get started into the plans supplies ect. So I'm looking for a bulk/wholesaler of 1 inch EMT conduit. Any dome builders out there have some good leads?

if you want EMT, try Platt, Eoff, North Coast. Best pricing likely on bundles of 100 sticks..

In electrical trade this is a commodity item, and prices change very rapidly, often daily

Also Home Depot

[Dork]

Seems like it's early enough to not be in a big rush to buy new conduit. I'd check metal recyclers and construction sites for cutoffs that are long enough for the dome you're planning.

Check the phone book for metal and electrical supply houses. You may or may not be able to get something cheaper than the big retailers.

[unjonharley]

There is a metal cuting band saw on sale for 160$ at Harbor Frieght also.

[timburly]

not planning on buying the conduit for some time.....just trying to get things in order. Don't wan't to do what ive done in years past and do things last min :)

but then isn't that the burner way LOL

[EspressoDude]

It will be more $$$$ later..

Copper wire has doubled in the last year, 8x over 20 years.

Don't wait too long. You might check some big Electrical contractors for job scraps/remnants. If not a full stick it usually gets tossed at end of job

[StevenGoodman]

Also, you might look into buying an existing dome from someone. People build them, use them for a few years, and then decide they don't need them.

Our camp brought a nice "steel" dome (not EMT) this year, and we never even got around to setting it up! I expect we will decide to sell it soon.

[Toolmaker]

Just cut up my tubing today, I went with 6061 Aluminum as opposed to the conduit. It cost a fair amount more but will be stronger since the walls are much thicker than the el cheapo conduit. I used the plans from the folks at spacelounge (THANKS SPACELOUNGE!!!). Been planning on making one for years now and finally got around to doing it. I am engraving the pieces tomorrow. I am going to drill holes on the inside and put small eyebolts in so I can hook stuff up on the inside. I will be able to hang stuff up along the inside to keep more room available. I was think of maybe a net/hammok but have to test the strength once the frame is assembled. The shade cloth I havent made a final decision on. Green to match the theme is only like 60-70 percent and I am more favorable to black which is like 80+.

[MikeVDS]

Hammocks should be fine. We used them this year on a EMT conduit dome with 3-4 foot struts.

Parachutes make nice, cheap covers.

How did you crimp the ends of the aluminum conduit?

[geekster]

So the minions are requesting a dome for the 2007 burn. Thought I would get started into the plans supplies ect. So I'm looking for a bulk/wholesaler of 1 inch EMT conduit. Any dome builders out there have some good leads?

If you want to run down to SF you might be able to buy our dome. We are getting rid of it. Nothing wrong with it, just don't want to mess with it anymore.

[Dork]

I'm also interested in how the crimping/drilling goes, if that is how you're joining them. Aluminum is not quite as easy going as steel.

I hate parachutes. They catch the wind and usually don't quite fit right. If you can swing the shade cloth you'll be very happy. If you hunt around you can find light colored 90% or just use two layers of 60%. We had 60% this year and I would have preferred something a little more opaque.

[Toolmaker]

I'm also interested in how the crimping/drilling goes, if that is how you're joining them. Aluminum is not quite as easy going as steel.

If you plan on using counduit it's easy.. you just need a hydralic press. Cheapest place I have seen em is where Unjon mentioned. Matter of fact harbor is a good place to get alot of tools cheap but remember you get what you pay for. Since I used something stronger I had to use oxy/acet torch to heat the end than press em flat.

Drilling Alum is actually easier if you put a center punch in, you can use a drill press and use a vise please. NO GLOVES!! A Glove can get you caught up something awful. If you MUST drill by hand than use lower RPMs and be careful, Alum is kinda gummy and will tend to grab the drill when the tool loads up. Again the center punch will give you a good spot to start your drill so it won't "walk".

[MikeVDS]

[quote]
I hate parachutes. They catch the wind and usually don't quite fit right.
[/quote]
I've only done one, but we actually designed the dome to fit a parachute we found on e-bay. Fits perfect and clips on nicely. Haven't had any problems yet.

[LeChatNoir]

Hey Toolmaker...

I was a CNC machinist for about 7 years running WEDM machines in a tool and Die shop. I could run all the other machines in there too. Now I bang an anvil for a living. Lots of good skills were picked up in those years spent in that shop.

For our dome cover we used a silver tarp with white camo netting over it in '05. Kept it very cool and comfy.

'06 was just the silver tarp and it was much warmer.

If you go with a solid membrane, black will cook you alive, man. The sun there is intense. Shade cloth might be less so, but either way, the lighter the color the better.

We used 3/4" EMT for our 23' dome and it works great. I'm thinking of building a better one eventually and like your idea of 6061 tubing. This year we also added rooms off the dome to form bedrooms arrayed around a central communal space. Couple that with hanging plywood shelves and it worked out great.

[diane o'thirst]

I can attest to Aluminet as a dome cover. We used ~600 sq. feet of it on our common area this year and it's nicely transparent while providing shade. Temps under the 'net were 10 degrees below ambient outside.

It can get rather pricey (35¢/sq foot for 90% shade) and it's delicate. You have to use special gripper-type grommets with it but they come with the cloth. It breathes, it's not very heavy (I estimate our hank weighed about 20 pounds all told) and minimum order is $200. But our camp certainly didn't regret the purchase.

[Ron]

....

If you go with a solid membrane, black will cook you alive, man. The sun there is intense. Shade cloth might be less so, but either way, the lighter the color the better.....

Actually, having used black shade cloth for a while now I can attest that it works just as well, if not better than, lighter stuff. Counter intuitive, I know, but it jibes with the observations of myself, my camp mates, and the hundred or so folk who lounge under our black pyramid at any given daylight time in BRC. Here's my guess as to why;

The sunlight hits the black shade material and a big chunk of the available light energy gets soaked up. The black shade material gets hot as hell. But the people under it are hit by light which now has much less available energy to produce heat than it would have had it passed through a white barrier. A bit of breeze, the fact that heat travels up, and the space between the black shade cloth and the folks under it all add up to making black shade cloth the way to go. If we're talking about actual shade cloth, engineered and manufactured to block light while allowing air flow. If it's black canvass vs. white canvass I don't know which wins but my money is on the white.

Ron

[LeChatNoir]

I was thinking more of a situation with it drapped over the dome, covering it almost completely, rather than strung above an area with the sides open. But then again, it may well work just fine like that even, since it's perforated. Airflow is pretty important whatever the cover, though.

[Ron]

I was thinking more of a situation with it drapped over the dome, covering it almost completely, rather than strung above an area with the sides open. .....

Cool, 'cause that's what I was describing. :) The shade material of our pyramid goes from the ground (where it's staked down to make a playa barrier for the sod) to the apex, 26' up. Folk are able to lay comfortably from the edge all the way up to the top, on the tower.

As a camp we had much discussion about the black color, but in practice it's worked wonderfully the past few years.

Ron

[LeChatNoir]

That's really pretty interesting... I suppose the fact that there is airflow through the material completely inverts the way the cover functions, making black actually a better cooling choice. Weird...

Well... maybe not weird, but at least a bit surprising and counter intuitive when first examined. I'll have to explore this idea now.

[timburly]

We're planning on a dome party some time this winter in Portland Oregon. We will have an EMT cutter, hydraulic press, press plates, as well as a drill press to complete the cutting, smashing, and drilling of the conduit.

If there is any interest in joining us let us know :)

/timburly

[Fex]

If you have any question about black vs. light colors being better for desert shade structures, just google "bedouins" and look for pictures. These desert nomads have been using almost exclusively black tents since time immemorial, and their entire culture is based on living in the desert, not just visiting. their tents are like the black robes that many of them wear -- black enough to block the sun but billowy/airy enough to negate the radiant heat.

[diane o'thirst]

Take a look at desert-dwelling animals, like the oryx and Akhal Teke horses. Their hair has a silvery sheen to it.

I was going to build a bamboo dome but I decided on building a hexayurt instead. I have a couple bamboo sources, enough to make an 8' radius 5V dome, but I'm not a math whiz and one still has to buy/make the covering. Besides, I saw how small a hexayurt compacts down into

[MikeVDS]

As a color you're better off with a more reflective color (silver is best but white works well too). Unfortunately it's not that simple. You want to reflect light, prevent too much from penetrating and allow the wind to pass through to remove excess heat with the typical shelter design. Light color breathable materials typically let more light pass through than dark colored breathable materials. If those are your two options the dark color may work better because less radiation will pass through to heat up things inside the tent and the breeze passing through will take away most of the heat collected by the dark colored material. The grass filled pyramid is the perfect example of this. The material easily let a breeze pass through and was dark enough to keep most of the sun out. To keep as much sun out with a lighter material you'd have to constrict the wind flow so that you would not get as much of a breeze, allowing heat to stay trapped in the material, essentially making a low powered oven.

[Bob]

Thy dome is as a flock of goats, that appear from Mount Gilead.

[diane o'thirst]

Question (and mild thread drift):

Thinking of painting the outside of the hexayurt silverish (sheen, not reflective) over white primer, and the inside black, sod-over-tarp floor. I'll be using evaporative cooling (a sprayer shot in the air from time to time). Material will be 2-ply corrugated cardboard with one door and two windows.

The intent is to keep it warm at night and cool during the day.

Workable?

Side note: Grass has been shown to be 12 degrees cooler than hard surfaces.

[MikeVDS]

That might work well. I'd be a little worried about wind if you just use one layer of that cardboard.

There are 3 main components to heat transfer, radiation (infrared or light energy), convection (caused by flow, usually air or water), and conduction (heat transfered by material touching). By insulating your structure to all three of these you can keep a more constant temperature. Reflective surface keeps your structure from absorbing radiation. The smaller the surface area the less convection from the wind will effect it. This can also be countered by reducing conduction from the outer layer of the structure to the inner layer. An air gap is usually the easiest way to insulate. Fiberglass insulation creates pockets of air and prevents it from flowing, which is why it works so well. Corrugated cardboard also works well but I'm not sure just 1 layer will work well. I hope you plan on more than that.

By adding grass you are adding a large heat sink. Grass is mostly water and can hold a large amount of energy proportional to the same volume of air. So if you start with 60 degree F grass and introduce 80 degree air, it will absorb heat from the air and be able to absorb enough heat from the air to reduce it many degrees more than it will increase in temperature. It can work the other way by keeping a room warmer in cold temperature, but considering the conditions of the playa I think you may end up colder at night if you have grass than if you don't have grass, but on the plus side it should keep you cooler in the day as well. You also need to watch out in cold weather because grass has water and if you water it, you can get wet. Water is a good conductor of heat and if evaporated takes a lot of energy with it so can cause a lot of heat loss, which is also very beneficial during the day.

[diane o'thirst]

The hexayurt site shows how to guy it down (of course I'm bringing mylar strips and tennis balls for my lines )

I'm going for the 6 - 4x8' walls 8' ceiling model because my werewolf costume will be 6.5' tall and an 8-foot ceiling wouldn't be as aggravating to stand up in. Besides, I need to fit a queen-size aerobed.

Since when standing up, my head would be in the ceiling, I was going to paint the roof silverish and only have that one layer; the walls of course would be more than one but I don't want to have a ton of cardboard in my trailer. Two-ply corrugated has a lot of airspace and when stood on end is very strong. I have a book that describes how to make furniture with it.