Re: Keep the Heat B/Thermodynamics C
Posted: February 24th, 2013, 3:09 pm
For division B, regionals is 100-200, in 25 mL increments, so they weren't allowed to do 170ychen428 wrote:Isn't there a maximum of 150mL for testing???
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For division B, regionals is 100-200, in 25 mL increments, so they weren't allowed to do 170ychen428 wrote:Isn't there a maximum of 150mL for testing???
Most glues don't expand by any noticable amount (and in fact a lot actually shrink as they harden).sjwon3789 wrote:So could anyone answer my question: Are cement glue considered as "expandable glue?"
I don't really understand when they say "expandable glue." Doesn't all glues expand?
sjwon3789 wrote:So could anyone answer my question: Are cement glue considered as "expandable glue?"
I don't really understand when they say "expandable glue." Doesn't all glues expand?
Expandable glue is considered to be glues that greatly increase in volume when hardening, often turning into a hard foam. The most well known type of expanding glue is Gorilla Glue, if you've ever used it you'll know why. So if your glue doesn't do that, than you should be fine.sjwon3789 wrote:What about some glue that doesn't change size (solid)? It looks like it's expandable since it's solid but it's actually not...
Is there any type of list for expandable glues?harryk wrote:sjwon3789 wrote:So could anyone answer my question: Are cement glue considered as "expandable glue?"
I don't really understand when they say "expandable glue." Doesn't all glues expand?Expandable glue is considered to be glues that greatly increase in volume when hardening, often turning into a hard foam. The most well known type of expanding glue is Gorilla Glue, if you've ever used it you'll know why. So if your glue doesn't do that, than you should be fine.sjwon3789 wrote:What about some glue that doesn't change size (solid)? It looks like it's expandable since it's solid but it's actually not...
As for cement, real cement glue consists of a solvent often containing dissolved material of whatever the glue is meant for(ex. ABS cement will have dissolved ABS in a bottle of solvent). Cements work by actually chemically melting the surface and then in essence welding the two pieces together. Unfortunately many glues are called cement that aren't really cement.
You could search google for a list, but since the number of different glues is so great(practically infinite), you're unlikely to find a useful list. It should just be common sense to identify an expanding glue. Let a test sample harden and if it grew in volume and is now full of air bubbles, it is an expandable glue. If it didn't, then its not.awesome90220 wrote:Is there any type of list for expandable glues?harryk wrote:sjwon3789 wrote:So could anyone answer my question: Are cement glue considered as "expandable glue?"
I don't really understand when they say "expandable glue." Doesn't all glues expand?Expandable glue is considered to be glues that greatly increase in volume when hardening, often turning into a hard foam. The most well known type of expanding glue is Gorilla Glue, if you've ever used it you'll know why. So if your glue doesn't do that, than you should be fine.sjwon3789 wrote:What about some glue that doesn't change size (solid)? It looks like it's expandable since it's solid but it's actually not...
As for cement, real cement glue consists of a solvent often containing dissolved material of whatever the glue is meant for(ex. ABS cement will have dissolved ABS in a bottle of solvent). Cements work by actually chemically melting the surface and then in essence welding the two pieces together. Unfortunately many glues are called cement that aren't really cement.
In the two competitions, I have had so far, I would have to say, YUPsjwon3789 wrote:Also, do we need to take out our beaker? Like, my beaker is attached to this insulators (not transparent)...?