Search for polyurethane rubber in Topics


What flexible rubber can i use that will stick to ceramic to make it shock proof?

When the ceramic is broken it does not fall apart completely because its bonded with rubber

Question by abigailjade    |  last reply


Trying to find a silicone/rubber/plastic sealer for cedar twigs with needles

Hi.  In crafts, I use cedar twigs with the needles attached and do not want to undergo the 5-6 wk process of preserving them with glycerine.  Right now, they are spray painted/polyurethaned.  Have tried glue and hair spray as well.  When these die...they become brittle and shatter at a touch.  I want something clear as  I will continue with the spray paint but need it to keep the needles in place, even if broken.  Any ideas?  Please email ragtag435@charter.net.  Thank you thank you thank you.  : )  Stephanie

Question by ragtag    |  last reply


Convert Crayons into 2mm+ Leads Like Graphite Lead

Hello! I want to recycle crayons and thought of converting them into 2mm lead or larger in diameter (since there’s only a certain thickness where crayons can be sturdy). I also thought the crayons should be mixed with something since they’re wax. I was thinking of buying a silicone mold rubber to make a mold (may make the lead bend since it’s flexible but easy to remove), a polyurethane mold rubber, or a protruder like the old fashioned way. Silicone mold rubber is expensive ($30+). I originally thought of it as a craft, but it’s too complicated for a craft. Thank you for your time!

Topic by TrixiaL    |  last reply


The Swallowtail Challenge.

Apparently, swallowtail butterflies have posed a bit of a puzzle to the sort of chap that studies that sort of thing. Butterflies actually have two pairs of wings - fore and aft, if you like.  Most butterflies have these pairs separated, to allow greater control over their flight, but swallowtail wings overlap, effectively becoming a single wing. They are stuck with a simple up-and-down flap.  The puzzle was; where does the control come from. It is hard to measure the forces acting on and in a live butterfly, so the researchers built a model - a small version of the hobbyists rubber-powered ornithopter, the same size and weight of a real swallowtail. They cast replica wings from fluorocarbons and polyurethane, and set it off in front of slow-motion video cameras. The conclusion? The unique shape of the wing provides automatic control - the combination of flexibility of the wing and the rigidity of the veins provide a passive control and stability. The point? Why am I posting this here?  As a challenge: the swallowtail ornithopter was (except for the wings), very basic - wire frame and a rubber band. How small could such an aircraft go? How tiny could you, dear reader, build a working ornithopter? Institute of Physics article. (Free registration required to read it in full, if you are quick)

Topic by Kiteman    |  last reply


Avoiding corrosion when bolting galvanized steel drawer slides to aluminum for camper van bed

Hey guys,Going to build this bed:or something very similar. She says she has 6 sliders at 100lbs each, but I imagine she has 6 slides at 100lbs per pair. Either way, I've already purchased 3 pairs of 500lb drawer slides. The problem is, they're galvanized steel. How do I attach them to aluminum L beams? I can use some thick mil rubber tape between the two materials, but what about the fasteners? Some sort of plastic washer and polyurethane sealant around the head and threads touching the galvanized rail side? What should I use to isolate one from the other?FWIW, I'll probably use 6061 for the frame, which I believe has an anodic index of .9-.95, and the zinc rails are, I believe, 1.25. They're within or close to the .25 threshold so am I worrying about nothing?Cheers

Topic by withalligators    |  last reply