I don't recommend buying epoxy in the syringe. I used to use it all the time, but after about three or four uses, if you're not VERY careful, one of the tubes will likely plug up just a little bit thus making it difficult to get equal amounts of epoxy, which is important! I recommend going to a hobby shop and buying the stuff that comes in two 4oz bottles and while you're at it, buy some mixing cups, which will be little clear plastic cups that you can measure the right amount of epoxy every time. What I have noticed is that the epoxy itself is denser than the hardener, so if you put the epoxy (usually the clear one) in the cup first, then the hardener, and hold it up, you can tell what you need to add to make it even. The cups that I have a set of lines on the side...2.5, 5, 7.5, etc, that you can use, so when you get to 2.5, stop, then add the other part until you get to 5, and you're mixture will be almost exactly perfect. I personally prefer, after the two are even, to add one or two more drops of hardener, just in case.
If you've gots lots of money, splurge and buy a set of West Systems epoxy or similar. I'll let someone that knows more about that stuff to talk about it...
CARL!!
Usually, the 12-20 minute epoxy is what you'll want to use for most applications, and when you have mixed it, the 12 minute stuff is thicker than yellow glue, but not by much. As the time goes up, the epoxy gets thinner, which is why most people recommend buying 30 minute epoxy for HPR, because it is thin enough and has a long enough setting time that the epoxy will soak into the part for a STRONG bond. Also, for doing fillets, I use 12 minute epoxy, since it is thick enough that it won't run and you block it with a tape dam in the front and back. Does anyone has a pic showing a tape dam?
OH, BTW, I use toothpicks for mixing the epoxy in the small cup, and I don't really follow any set pattern, but usually what I'll do ispick the cup up, turn it a little so it's at a angle, and most of the epoxy is at one side of the cup, and fold the epoxy into itself. I'll do this for about a minute, then I'll return the cup to level and go around the cup in a circle and get all the stuff off the bottom, then put the cup an angle again a fold it over itself some more.
That's basically all I know about epoxy and most of its uses. This was just for standard epoxy. There is Finishing Epoxy, with is thinner and takes a LONG time to set, which allows it to soak into fiberglass real well. DO NOT USE FINISHING EPOXY FOR GENERAL CONSTRUCTION!!!!!!!!!!!! It is too flexible and not strong enough for that use!
Jason