Glue hint!
 

If you want to make something watertight, or if two things have to remain together for life, you may want to use glue.
One of my favorites is EPOXY two-component glue. It's specifications are outstanding!
One rather big disadvantage is it's long curetime especially when you use small quantities (generaly the case). One drop can take 1 week to completely cure (harden).
Now the hint:
Put the needed quantity of the two component (50%-50%; using more hardener reduces curetime anyway but alters the good specs of the final product) in a non-metalic recipient (you can take the bottom of a plastic bottle). Don't mix (blend) the components yet. Put the recipient in the microwave (+- 40s at 600W). If you spot fumes switch off the microwave sooner. The components should be liquid as water right now.
Mixing of the components is very easy (piece of cake ;) )
Apply this homemade glue where needed (take off grease before with isopropanol; you may use another cleaner but isopropanol is safe for plastics!!!!).
Your curetime is reduced from one week to less than an hour!
Rate this one!
After I found out this behaviour and spoke with a German scientist, this microwave-procedure is used on industrial scale.
PS don't try *everything* out in the microwave; it could be dangerous. This hint however turns out to be safe. Keep an eye on the proces and stop the microwave when you see fumes.

good tip... but does your food tast the same when you use the microwave? :D

No tast (no bad taste!)
 

No, the food has no bad taste; therefore it is a good hint :D

I use "Ace Hardware Marine Epoxy". Very strong bond, completly waterproof and will glue anything. 90min set time, 12 hours for a full cure.

Great stuff.

@WebMasta33
 

Hmmm, seems that they added some accelerators to that mixture. Keep us posted if you might try the microwave-tip.
Anyway we agree on the outstanding results with EPOXY ;)

hmmm, well epoxy is heat activated (ever felt how it gets warm when is reacts?) so this makes a lot of sense. Good tip Gadget!!

Right, epoxy is exotherm. But for small volumes, the released heat during the chemical reaction is hardly benificial for the reactionspeed. With some raw basiccomponents you can get up to 1 week curetime.
Heating up has an influence on reactionspeed. That's true. The microwaves here are rather used as an reaction-initiator (the 'mixture' quickly cools down after removing it from the oven, but the benificial effect remains).

yea kinda depends on what ur doin and what ur gluein...epoxy is great (good tip btw)..but i luv aquarium glue for clear stuff and water tight stuff(basicly 100% silicon)

Yes, you're right but I said epoxy is ONE of my favorites :D
Silicone is an other one...
Unfortunately I have no tip for silicone apart from the warning when using silicone as demoulding agent for polyurethanes. This could result in a splendid blowing of the PU (some solvents used in silicone could react as fysical blowing/foaming agent).
Need no picture of what is looks like when you intend to mould something and it finally turns ou to be 10 times the original size ;)