The word on playa dust and links for the newbie -

[gyre]

Yes to the silicone. and make sure you give wiring a generous coat. The first time I went to the playa I started having corrosion problems on the battery of my truck. That was solved using the little anti-corrosive felt rings you can get at an auto parts store for under a couple of dollars.


My research into the dust continues. Fascinating stuff.

Thanks ^Rhino...I'll check out those felt rings. All in all we'll have 4 batteries and we don't want them corroding. There's a tiny little semi-exposed wire couplet that holds our trailer fuse. If that fucks up we're screwed. It will be coated liberally.

I presume you're talking about a spray on electrical silicone?
I hope we're talking about the same form of silicone.
Silione dielectric grease is available in small tubes, but I recommend a large tub.
It will last you a while.
Carlton-bates or some other electronic supply house is the easiest source.
Bearing grease, especially high temperature moly, can be used in an emergency, but bear in mind that some grease is conductive and/or flammable.

Silicone conformal coating or something similar can be used on circuit boards and some rigid circuits.
I love the clear silicone.
Best clear coat I've ever seen.

I haven't had any electrical corrosion issues myself.

(Silicone caulk is extremely corrosive to metal.)

[dewnorth]

Two questions:

1.) I've seen several numbers mentioned as the pH of playa dust. Does anyone have the "final answer"?

2.) Bandanas seemed to work to keep out dust.I can see through the holes in bandanas. So was I deluding myself? Are bandanas truly effective?


The BLM's exhibit at BRC 2009 said the EPA is concerned with dust particles 10 micrometers or smaller because those particles "generally pass through the nose and throat and enter the lungs."

They haven't studied dust levels at Black Rock Desert, but they studied Owens Lake Bed. When winds got above 20 mph, dust levels were way above safe levels. And with winds above 30 mph, dust levels skyrocketed. (But I guess we didn't need a study to tell us that.)

No information was given about dust particle size at Black Rock Desert, so their information was anecdotal at best.

[gyre]

I know one doctor out there whose whole family wears high quality surgical masks all the time.

[ygmir]

well, one statistic might by of great value for long term effects:

no one who went to burning man (BRC, playa location, specifically), that is still alive, went more than 21 years ago........

[ZaphodBurner]

I apologize if it offends your sensibilities. If you consider it lazy, so be it.

Fuck everybody else and their e-playa opinions. I enjoyed reading your post. I have to admit I had to read it twice to get it, and I have to take your data on faith, but, thanks.

The vinegar+playa dust=science fair experiment caught my interest, also the HCl comment. Are you saying not to use HCl, even on concrete, or just the muriatic acid form (extremely concentrated)?

Spraying your feet with vinegar water feels a little better than using straight water. For my scientific research I filled one spray bottle with tap water and another with diluted vinegar and applied them to the soles of my well-playafied feet. After ten long minutes of preparation and a few seconds of hard research my results were conclusive; the one that smelled funny felt better.

I will not be attempting this experiment with HCl.

[^Rhino!]

Thank you, Zaphod Burner.

In answer to your question,the strength of hydrochloric acid is measured either in 'normality' or 'molarity', dependent upon what your needs are in doing chemistry. Pure HCl is a gas., but when it gets down to 10% concentration it's used as a concrete cleaning agent called 'muriatic acid'. Still, at that concentration it can burn skin, sort of like a sunburn feeling. Wear plastic or butyl rubber gloves when using.

At 1% and less concentrations, it's used as a reagent in testing in geosciences along with Alizarin Red (a dye) to separate calcite from dolomite in rocks. Stains calcite red, in the same reaction that colors easter eggs red.

Even lesser concentrations occur naturally in the human body. It's the main component of 'stomach acid', that helps you digest your food.

Dewnorth, I haven't been able to find a reference on particle sizes in playa dust. I assume sand, silt, and clay sizes are present, but in what proportions I don't know.

As for pH, to get a good pH measurement, it has to be put in DI (distilled deionized) water and then the pH is taken twice, once in a water only solution, and then in a CaCl (calcium chloride) buffered solution if you use the USDA method. I don't know the answer to that either.

[Token]

So sticking your playa feet into a tub of your own vomit would be therapeutic!

I love me some science in action.

[EmilyD]

Yes to the silicone. and make sure you give wiring a generous coat. The first time I went to the playa I started having corrosion problems on the battery of my truck. That was solved using the little anti-corrosive felt rings you can get at an auto parts store for under a couple of dollars.


My research into the dust continues. Fascinating stuff.

Thanks ^Rhino...I'll check out those felt rings. All in all we'll have 4 batteries and we don't want them corroding. There's a tiny little semi-exposed wire couplet that holds our trailer fuse. If that fucks up we're screwed. It will be coated liberally.

I presume you're talking about a spray on electrical silicone?
I hope we're talking about the same form of silicone.
Silione dielectric grease is available in small tubes, but I recommend a large tub.
It will last you a while.
Carlton-bates or some other electronic supply house is the easiest source.
Bearing grease, especially high temperature moly, can be used in an emergency, but bear in mind that some grease is conductive and/or flammable.

Silicone conformal coating or something similar can be used on circuit boards and some rigid circuits.
I love the clear silicone.
Best clear coat I've ever seen.

I haven't had any electrical corrosion issues myself.

(Silicone caulk is extremely corrosive to metal.)

WHEW!!! I'm so glad you clarified the spray on electrical silicone. I was going to use the caulk...that's what we artcar folks use for almost everything. I just naturally assumed....whew, and double whew! Thanks for checking that. ^Rhino you "rock"! ;-)

[chris2010]

I'm going to dispel a lot of rumors and stuff with this post about playa dust....

Thanks for the info!

[theCryptofishist]

Sometimes epa or osha or someone else with a lab will run these for you.

Can we have a show of hands for people who want more government agencies involved? And um, I don't know about OSHA, but EPA is not swimming in cash.

[robbidobbs]

OK, here's the 11 years of experience talking...
Skin will soak up the alkaline talc that's omnipresent.
That's the facts, Jack.
You can counter this with vinegar or whatever substance that you choose to neutralize the alkali. Chemistry bay-bee. Intoxication isn't an excuse.
Do not wear sandals or go bare-foot for more than a very short period of time. You will be fucked in 2 days unless you take extraordinary precautions. Just ask Box.

1. Wear good shoes and cotton socks.
2. Wash your feet with vinegar water daily if you don't.
3. Slather your feet with moisturizer before retiring to your sleeping quarters without fail.
4. If you get playa-foot, you're fucked for about 3 months.
5. Playa-foot sucks.

YMMV.

(Loving you, Fishy)

R.

[gyre]

Sometimes epa or osha or someone else with a lab will run these for you.

Can we have a show of hands for people who want more government agencies involved? And um, I don't know about OSHA, but EPA is not swimming in cash.

Srsly?

EPA only exists to serve as an industry front to pacify the public, while business as usual continues.

Nightline is doing a story on that right now.
Well known that booms don't work.
Public relations.

Any time epa can serve a useful purpose, I'm all for it.
Those labs stay open whether they have anything to do or not.
And identifying hazardous substances seems within their purview.

But you could always try a government supported school.

[Bling]

Rhino, I was hoping you'd answer the question about whether Playa dust contains respirable crystalline silica, which is a carcinogen? I've heard that this was mistaken, but would love to hear that from an actual geologist who has looked at the composition of the dust.

[Bob]

Dewnorth, I haven't been able to find a reference on particle sizes in playa dust. I assume sand, silt, and clay sizes are present, but in what proportions I don't know.

Overview by Mike & Barbara Bilbo re: the area landscape, citing numerous geological, hydrogeological & geomorphological studies:
http://www.blackrockdesert.org/friends/ ... -landscape

A decade ago I tested a surface sample from the 1999 event site. The fines content (clay and silt) of the sample was 99 percent (passing the 200-mesh sieve), ie negligible sand. The sample had an Atterberg liquid limit of 44, with a plasticity index of 18, indicating a borderline clay to silt soil of medium plasticity (USCS classification CL to ML).

So, the near-surface playa soil may be about half clay, half silt. As the above article states -- "no source of fine sand exists in the area". Even the aeolian dunes on the playa margins are comprised of clay and silt, not sand. Deep below the surface, and near canyon washes, I'm sure you'd find coarse-grained sand and gravel deposits interfingered with the clay and silt.

In any case, it would be interesting to go back and sample from more locations mid-playa and along the margins, and estimate the proportions of clay species via x-ray diffraction. My sample was from about the top 4+ inches of soil, but a sample skimmed from the uppermost crust might have a much higher content of alkali minerals, though frankly the alkali content wasn't of much interest to me. The purpose of my sampling was to obtain a few buckets to do testing of various burn scar prevention methods, which were then reviewed by Mike Bilbo when he was still with the Winnemucca BLM office.

[^Rhino!]

Bob,

It's a lean clay to an elastic silt then, right?

Then the article by Keith Papke makes some real sense. He's a geologist with the Nevada Bureau of Geology and Mines, who wrote an article in the journal Clay and Clay Minerals.

I'd strongly suspect that you have a mixture of halloysite and montmorillonite as part of the clay fraction. And remember something, and this is something that some geotechnical engineers forget from time to time, that the most persistent specie of clay PARTICLE SIZE is not necessarily a clay MINERAL. It's QUARTZ.

The halloysite in the mix comes from hydrothermally-altered (hot springs in the area, right? Makes even more sense) pyroclasts of volcanic rock from the Tertiary-aged volcanics flows in the area. I'd suggest that you get a copy of the article for your perusal, and maybe we can discuss it here, too.

It's free ati:

http://www.clays.org/journal/archive/vo ... 9-2-71.pdf

I still want to do XRD, and the little tubules of halloysite might just give me an excuse to talk somebody into doing it just for a reference sample. The best pics I've seen of the stuff are SEM photomicrographs:

http://www.scielo.br/img/revistas/aabc/ ... 8fig11.gif

http://www.scielo.br/img/revistas/aabc/ ... 8fig9d.gif

Hope that's the kind of opinion you're looking for.

[Bob]

Rock flour from glaciation, arid weathering or whatever is still clay from an engineering perspective, and would still have x-ray diffraction signatures. And yes anywhere you have volcanics you'd have montmorillonite as a product, but I have a feeling the playa is a smorgasbord of fine junk.

[gyre]

I blame the dpw.

[Bob]

I blame the dpw.

For what, the serpentine dunes, the access roads etched into the surface, or the persistent patchouli smell at the hot springs?

[gyre]

Draining the lake.

[^Rhino!]

You could have any of the following list of minerals from the smectite greoups:

Nontronite
Saponite
Bentonite
Montmorillonite

I know quite a bit about them.

[Bling]

And silica? Pretend I know nothing whatsoever about geology and you'll be pretty much on track...

[Snow]

yes there is plenty of silica contained in playa dust

[Bling]

Respirable crystalline silica?

[Snow]

Yes crystaline silica, whose most common form is Quartz. And as noted above seems to be the most commonly occuring mineral in playa dust. Which makes sense since the rocks that make up most of the mountains around the Black Rock Desert are relatively high in quartz.

Don't forget about argilicious generation of clay minerals. Argilic alteration is a dominant mechanism round these parts. Our Au industry depends on it.

[Bling]

My understanding is that respirable crystalline silica is a particular size of particles. Do you have proof that this is present in Playa dust?

[Snow]

"proof?" Scientifically defendable proof, no, as I have not collected and analyzed a sample myself, but sounds like Bob has. Based on his numbers (99% passing of a 200 sieve) 99% of his sample (of playa which may very from blowing dust slightly) was less than 74 microns in size. Given the high quartz content of the playa, as mentioned several times, would lead one to believe that yes there is a high amount of respirable quartz (silica) in the playa dust. I need to research exactly what the partical size that makes it respirable, likely defined by OSHA/MSHA. But playa dust is a VERY fine dust indeed, and as a burner know that I can breath it in.

I'm no doctor (a geologist/engineer) but I'd say try to breath as little as possible.

[Bling]

We were planning to breathe as little as possible. This pdf has good info--but I didn't see anything about particle size: http://ntp.niehs.nih.gov/ntp/roc/eleven ... 61sili.pdf.

If you look at the periods of time needed to cause silicosis, it's important to keep in mind that occupational exposure may be limited to an hour or two per day--vs. potentially 24/7 x 7 days (168 hours) in one week on Playa...

[Bob]

Doesn't the Survival Guide recommend a dust collection system in every camp?

[ygmir]

good call, Bob.......I'll set out my "little black book", it collects a lot of dust........*pout*........

[Ugly Dougly]

Draining the lake.

Re-fill it!

Will there be a Dust Collection Station near Center Camp this year? Will ^Rhino have his XRD in good repair and running at full capacity?