ORIGINAL: trailingedge
The type of solder you use matters less than making sure it's cleaned and heated properly. I've used both silver and rosin core with satisfactory results. I use a weller portasol. It's a little butane soldering iron/torch. It's a little on the pricey side, but once you get one, you'll pitch all of those bulky irons that tie you to the wall and are never hot enough when you need them to be. It also works really nice for removing those sections of monokote you would normally use a hobby knife for (middle of the horiz stab/ bottom of the verticle stab).
This is VERY true. Plenty of heat, and a well cleaned and fluxed joint prior to wicking in the solder will give a better result with electronics solder than a poorly prepared and inadeqautely heated silver solder joint.
I do prefer a silver content in my high stress joints such as landing gear or cabane struts. Radio Shack sells a silver solder paste in a syringe style tube. Its much stronger than electronics or plumber's solder. Its expensive... But you don't use a lot. One $4 (appx) tube will do 3 or 4 soldered landing gear assemblies.
Note... once you have soldered it up with the rosin core stuff.. if it wasn't strong enough to hold, you have to clean off ALL the old solder before using the silver solder... or the joint just won't be right.