Welding blanket for big burn

tisha2 · Post by **tisha2** » Wed Jan 16, 2008 3:58 pm

hallo ~

i am looking for some silica groundcover, aka welding blanket, to go under our large-scale art project for this year that we plan to burn to the ground at the end of the week. it is pretty big - 16'x16', so we need at least 20'x20' of ground cover. Anybody got anything leftover from prior burns??

mucho grassyass!
~tish

BitterDan · Post by **BitterDan** » Wed Jan 16, 2008 5:11 pm

Do people actually put things under their burn art? I always thought they just burned them on the playa and then "turned" the top layer of soil. Is that not the way it's done? If so I need to rethink some things for next year...

motskyroonmatick · Post by **motskyroonmatick** » Wed Jan 16, 2008 5:19 pm

The waffle was built on a layer of sheet rock to protect the playa. I have not heard how that went in regard to the burn scar but it seems like an easy way to go.

Post by **AntiM** » Wed Jan 16, 2008 5:20 pm

The burns at Roach Lake (Singularity) used sheet rock under the art.

BitterDan · Post by **BitterDan** » Wed Jan 16, 2008 5:21 pm

Sheet Rock should be cheap. After all, Empire is the sheetrock capital of the world.

Dustdevil · Post by **Dustdevil** » Wed Jan 16, 2008 6:16 pm

The sheet rock did not work well at all. Between the material falling on it and the heat it failed. You cannot burn things directly on the Playa. This is a BLM requirement. Large items, The Man, Crude Awakening etc were burned on decomposed granite and then the granite is removed. Smaller installations use a variety of methods. Angel of the Appocalypse used sheet metal that was reinforced and elevated. Wood under sheet metal done NOT work. The heat will start the wood burning. Bricks and corregated metal will work. Think "air space" between the Playa and the fire.

sputnik · Post by **sputnik** » Wed Jan 16, 2008 6:20 pm

We did the sheet metal with wood under it (with the org's guidance) in 05 for the Windmill burn. The wood ignited and we had 3 very large burn scars. Really bad. You need to get non-flammable something under your burn, and it needs to be something that can hold up when whatever you're burning collapses.

Good luck Tisha

tisha2 · Post by **tisha2** » Wed Jan 16, 2008 7:50 pm

thanks y'all ~

actually there are just a few org sanctioned methods of preventing a burn scar (yes, Dan, there has to be something under your art preventing it from leaving a mark on the playa when it burns). for the size of our project, the blanket seems the best option. since people will be climbing on it, and due to the size, 20 feet by 20 feet of sheet metal balanced on bricks isn't going to work. burning art guidelines are here:
http://www.burningman.com/installations ... ntion.html

of the options offered, due to the size and estimated heat, we've decided to go with the blanket covered in sand (which is what they say there that they use under the man - might be the DG you mentioned).

thanks for the help all! if anyone hears of a leftover welding blanket we can use let me know! danka!

BitterDan · Post by **BitterDan** » Wed Jan 16, 2008 7:58 pm

Do you mean sand or playa? Because I think sand would be considered MOOP wouldn't it?

Bob · Post by **Bob** » Thu Jan 17, 2008 10:35 am

I wrote the first draft of the org's web page on all that a few years ago after experimenting with a few different configurations of fabric, steel, sand, sheetrock, etc.

Sheet rock might seem good, but the paper smoulders under high heat and scorches the playa surface black, leaving a mixture of crumbled white gypsum and black ash behind. Might work on top of a layer of sheet metal, depending on how intense the heat is.

The higher quality fire-resistant fabrics eg silica welding blankets might seem good to use alone, but it's definitely not designed to be subjected to direct & prolonged intense heat. It burns through under a small wood fire -- I tried it. However, it does work great as a failsafe underneath a layer of two or three inches of sand. This is what the org has used for many years under the Man, and in fact they switched from the higher cost silica fabric to the cheapest fiberglassing cloth they could find, because the sand layer does the main job of insulating, and the function of the fabric is to segregate the sand & ash & fumes from the playa surface.

But there are many ways to it, including welding up raised steel supports with a sheet or plate steel tray on top -- which is what the burn platforms along the Esplanade are.

Try contacting the email links on the org's web page to find out how to obtain & use sand or whatnot, and experiment beforehand on how to raise & contain the burn so it doesn't contact the ground.

tisha2 · Post by **tisha2** » Thu Jan 17, 2008 10:58 am

thanks, Bob ~

i had sent an email and am getting info today. They do seem to mean 'sand' and not 'playa' as they tell you where to get it. I was also wondering about how to keep it from blowing away...

y'all. rock.

~t

Bob · Post by **Bob** » Thu Jan 17, 2008 11:07 am

AFAIK the DG (decomposed granite) sand for some of the funded burns is trucked from Spanish Springs down toward Reno/Sparks. The material is only $10/ton or so, and the main cost is in the transport. It's fairly coarse, similar to what's used on horse & walking paths, so very little blows away. Around the Man the carpenters typically stake down the fabric edge with a beveled 2x2, which retains the sand topping.

Toolmaker · Post by **Toolmaker** » Thu Jan 17, 2008 1:46 pm

Bob: Wouldn't a gravel type media work as well? Less chance of MOOP anywayz.

Bob · Post by **Bob** » Thu Jan 17, 2008 8:38 pm

Sand is easier to rake, sweep, shovel, level, drive stakes thru, & walk on.

Gravel has greater permeability, which would let more fumes thru. And crushed gravel might puncture the fabric.