For the wind tunnel I need to bunch together hundreds of 2" sections of drinking straws to form the flow guides that will hopefully force the air flow to become approximately laminar. I thought about using spray adhesive but I figured that using glue would be extremely messy and would probably cause more turbulence than it would have eliminated.
Then I tried using my soldering iron to weld the straws together and it works very well...
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Then I tried using my soldering iron to weld the straws together and it works very well...
Look closely at the ends where the straws contact each other. At those points I quickly touched the hot iron on the plastic of both straws and they instantly fused together.
This is really handy because I can simply pack hundreds of straws into a cardboard jig (a cereal box will work perfectly) and just use the iron to weld all the straws into a single piece! I have only tried this with a few straws but I think this will work fine for a large mass of straws. The welds hold strongly although they do tend to ruin the smoothness of the plastic. I will only do the welds on one end of the straw block, the other end will have to be held in place by another means in order to have a good surface for the air flow to exit the straw bundle.
Try this for yourself and see just how strong drinking straws become when welded together. I am sure this would be an excellent construction technique for model aircraft makers. The bundle of 8 straws you see in the picture can hold 8 kilos of longitudinal compressive force without deforming! And since you're not adding the weight of adhesives, it's incredibly light.
The bundle above weighs about a gram or so but can support 8000 grams. Pretty amazing.