Public Lab Research note

Great set of instructions but ... the heat seaming video is sort of done from the wrong angle so you can't see what's happening. Any chance of posting one showing precisely where you put the iron? Do you put it on the metal rule and slide the rule down,

by skymonkey705 | August 14, 2020 15:40 14 Aug 15:40 | #24324 | #24324

Several years ago I built a 125860 cubic foot balloon,it had 22 gores one hundred feet long,a lot of seam sealing.Through a lot of trial and error and testing,I came up with a way that is fast and if done correctly as strong as the poly.I know this because I could stretch samples to more than 6 times it's length without failure.

First you need a soldering iron,a flat price of polished aluminum or stainless steel,or plate glass about 6X18 inches and a metal ruler.

Place the plate under the 2 layers that are to be welded,then about a half inch inside of the edges lay down the ruler,then slowly guide the soldering iron along the rulers edge.Move slowly along the edge making sure you don't go over the ends of the ruler.When that's done slide the plate and ruler into position to continue the weld.Practice on scraps first and try pulling them apart to test them,you will see that it is not so hard to do.I have done several hundred feet in one day this way.

Also instead of using garbage bags that require a lot of seaming,your local building supply stores carry 0.7 mil poly sheet in rolls up to 2000 square feet,in black or clear.

Hope I have been of some help,Doug.😊


Here's a heat seaming instruction set from @elainechoi89 that has some great photos attached, hope this helps!

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Thank you Doug! This is awesome. @mathew check this out—how's your balloon making going?

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