Feyerabend’s critiques the application of scientific theory to social prescriptions.  But this quotation struck me because it could be re-applied to the contemporary art world so easily.  Sophistication without content.  It is, however, fascinating how crude and superficial attacks on content-less sophistication have been subsumed into a sophisticated discourse.

oh man, venomous attacks against a vague subject like the “art world.”  I must be tired. oh well, POST!

Grassroots Mapping PDX 6/26/2010: helium flight from mathew lippincott on Vimeo.

Grassroots Mapping PDX 6/26/2010: Solar Hot Air flight from mathew lippincott on Vimeo.

From the solar balloon flights.  I really wish I could send these balloons above 150ft, as is RJ and I we only got shots of the beach.

/* rant

this is a great shot of me and robby kraft inflating a solar balloon on 7/27, taken by Samantha Mitchell.  We never got into the Sauve Island airspace though, the Sheriff told us to stop.  He was jovial, but wouldn’t give us a charge or cite what statute we were violating.  I actually had to chase him down and harangue him before he conceeded that he’d ticket us for “harassing wildlife.” The only wildlife we harassed was the pig tooling around in a pickup truck.  We had the decency to walk into the refuge on foot.

*/

Helium Flight

I’ve got over 800 photos that need stitching from this one, my dad and I went to a little over 1000 ft on the beach at Seaside, OR.

Solar Balloons:

Regular charcoal sucks, no matter how finely ground.  In my tests over this month I couldn’t get it to coat the balloon well.  My previous successes were with Char-Kole brand compressed charcoal, ground up.  Jeffery Warren copied my building instructions and tried charcoal in Georgia (EU) without success.

I still want to test lamp black, but Cabot pigments STILL hasn’t sent me samples (ordered them the 2nd week in June).  Go with iron oxide black (sold as tempura pigment, or from industrial suppliers).  Iron oxide black consistently generates roughly 500g of excess lift from a 12-foot tetrahedron.  the easiest way to test the lift of a balloon is to tie a water bottle to it and empty out the water until the balloon is airborne.

Use a mattress blower to disperse the pigment when the balloon is mostly full.  It pulverizes and disperses, and possibly, through proximity to the motor, charge them a bit.

I stand by my dislike of black HDPE, because it is weak and tears easily when hot.

Helium

My balloons have, until now been all solar, so these were my first helium flights. Helium is great. it rides proudly in the wind, owing to a favorable ratio of static lift to surface area/drag. But helium is expensive. I spent four times as much on helium as I did on all other supplies.  After flying my very thin HDPE .3mil balloons and watching the helium leak out over a 3 hour  period, I think a more substantial balloon aught to surround such an expensive gas.

I might try some PET film, which retains helium better, but it’s cost ($15 vs $0.50) makes me averse to it.

Or I might switch to hydrogen. I’m excited about this method of urine electrolysis. Apparently it’s far more efficient than water, and I’m already carrying it around!

Grassroots Mapping PDX 6/26/2010: heat seaming from mathew lippincott on Vimeo.

Taping Instructions

Follow the first two pages of my Balloon Building Guide to make a tetrahedron balloon.  Tape carefully.

My balloon guide’s rigging is for short flights in confined urban areas.  We’re going to use a different rigging for aerial photography.

One corner of the balloon is used for filling, and is tied off, like a trash bag.  A second corner is re-enforced, and a loop of tape attached.  To the tape is tied a short length of line.  The knot used is a Bowline.

Grassroots Mapping PDX 6/26/2010: Rigging a balloon for flight from mathew lippincott on Vimeo.

attach a swivel to the balloon so that any spinning won’t twist the line or the camera.

in the mean time, enjoy an entire Andy Warhol installation, reproduced and on sale from a Chinese wholesaler.

Conclusions

The four thicknesses I could find were .315 mil (millionths of an inch) .69 mil, 1 mil, and 3 mil. Two complications to the tests were that the .69 mil was white, meaning it had added pigment, and the balance was only accurate to 1 gram, so I wasn’t able to figure out the rate of loss.  I took photos of the balloons every 20 minutes from 10pm to 12pm, and then measured them this morning at 8AM.  I then re-filled the .69 mil and 1 mil balloons for a second round of testing, realizing I’d incorrectly filled them the night before.

The conclusion i could draw was that .315 mil loses 1/4 to 1/3 of it’s helium over two hours, which means it probably is a poor choice for helium balloons.  Each balloon had around 3 grams of lift.

.315 mil on the left.

.315 mil balloon after 2 hours, partially deflated but still floating.

The unfilled the white .69 mil balloon weighed about 3g.  Full, it barely registered on the balance, and this morning the balance still oscillated between 0 and 1g. The 1 mil balloon, which weighed 2g unfilled and registered 1g filled, weighed 2g this morning, with no appreciable loss of gas.   I should have noticed immediately that I’d screwed up, but I was distracted and cleaning the kitchen while running the tests. I must have filled the 1 mil and .69 mil balloons with a mixture of air and helium.  This is confirmed by re-filling them this morning and watching them float.

So I ran the test again, filling both balloons up.  The overnight test, although botched, was confirmed this morning.  Over two hours, you can see the 1 mil clear balloon lose lift, while the white balloon remains buoyant.

Why would thicker, clear HDPE lose helium faster than white .69 HDPE?  I believe it is the inclusion of metal oxide to tint the white plastic.  White pigment is either zinc oxide or titanium dioxide (or lead oxide in really old stuff).  This would also explain why the white HDPE is heavier than the thicker clear stuff.